diff --git a/backend/crates/gateway-admin/src/lib.rs b/backend/crates/gateway-admin/src/lib.rs
index 2ff747863..9c3e8981a 100644
--- a/backend/crates/gateway-admin/src/lib.rs
+++ b/backend/crates/gateway-admin/src/lib.rs
@@ -255,7 +255,6 @@ pub async fn initialize(
 
     let accounts = Arc::new(DefaultAccountsService::new(
         store.accounts(),
-        store.settings(),
         registry.clone(),
         snapshot.clone(),
         probe.clone(),
diff --git a/backend/crates/gateway-admin/src/model/accounts.rs b/backend/crates/gateway-admin/src/model/accounts.rs
index 1d4452ffe..84a44696e 100644
--- a/backend/crates/gateway-admin/src/model/accounts.rs
+++ b/backend/crates/gateway-admin/src/model/accounts.rs
@@ -1,6 +1,6 @@
 //! 多 Provider 账号目录与连接测试的公共事实。
 
-use std::{pin::Pin, time::SystemTime};
+use std::pin::Pin;
 
 use chrono::{DateTime, Utc};
 use futures::Stream;
@@ -9,151 +9,10 @@ use gateway_core::routing::ProviderKind;
 
 use super::{PageSize, Revision, observability::TimeRange};
 
-/// Provider 账号当前可用性；权威定义与字符串编解码在 gateway-core，此处仅复用。
-pub use gateway_core::engine::credential::AccountAvailability;
-
-/// 管理页使用的归一化账号状态。
-///
-/// 只回答两个问题：是否可调度、是否需要人工干预。具体错误原因不进入此枚举，
-/// 由 [`AccountErrorReason`] 承载；新增原因只扩展 reason，不改变分类。
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum AccountStatus {
-    /// 正常，可调度。
-    Normal,
-    /// 配额耗尽（持久化终态），等待额度恢复，无需干预。
-    QuotaExhausted,
-    /// 限流中（quota 快照级信号），自动恢复，无需干预。
-    RateLimited,
-    /// 管理员手动停用（`enabled = false`）。
-    Disabled,
-    /// 错误（过期 / 失效 / 封禁等），需要人工干预。具体原因见 [`AccountErrorReason`]。
-    Error,
-}
-
-impl AccountStatus {
-    /// 返回稳定 wire 值。
-    #[must_use]
-    pub const fn as_str(self) -> &'static str {
-        match self {
-            Self::Normal => "normal",
-            Self::QuotaExhausted => "quota_exhausted",
-            Self::RateLimited => "rate_limited",
-            Self::Disabled => "disabled",
-            Self::Error => "error",
-        }
-    }
-
-    /// 解析稳定 wire 值。
-    #[must_use]
-    pub fn parse(value: &str) -> Option<Self> {
-        match value {
-            "normal" => Some(Self::Normal),
-            "quota_exhausted" => Some(Self::QuotaExhausted),
-            "rate_limited" => Some(Self::RateLimited),
-            "disabled" => Some(Self::Disabled),
-            "error" => Some(Self::Error),
-            _ => None,
-        }
-    }
-}
-
-/// 状态派生所需的最小事实；由 store / use_case 各自构造，派生规则唯一。
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct AccountStatusSignals {
-    pub enabled: bool,
-    pub availability: AccountAvailability,
-    pub access_token_expired: bool,
-    pub quota_limit_reached: bool,
-    /// 429 临时限流（Redis 冷却）到期时间；`Some` 表示账号当前处于临时限流。
-    pub rate_limited_until: Option<SystemTime>,
-}
-
-impl AccountStatusSignals {
-    /// 派生产出运营分类。终态优先于瞬时信号：停用 > 配额耗尽 > 错误 > 限流。
-    #[must_use]
-    pub const fn derive(self) -> AccountStatus {
-        if !self.enabled {
-            AccountStatus::Disabled
-        } else if matches!(self.availability, AccountAvailability::QuotaExhausted) {
-            AccountStatus::QuotaExhausted
-        } else if self.access_token_expired
-            || matches!(
-                self.availability,
-                AccountAvailability::Expired
-                    | AccountAvailability::Invalid
-                    | AccountAvailability::Banned
-                    | AccountAvailability::Unknown
-            )
-        {
-            AccountStatus::Error
-        } else if self.rate_limited_until.is_some() {
-            AccountStatus::RateLimited
-        } else if self.quota_limit_reached {
-            AccountStatus::QuotaExhausted
-        } else {
-            AccountStatus::Normal
-        }
-    }
-}
-
-/// 错误分类下的具体原因；仅在 `AccountStatus::Error` 时存在。
-///
-/// 受控枚举用于展示与聚合，扩展不改变状态分类。
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum AccountErrorReason {
-    Expired,
-    TokenExpired,
-    Invalid,
-    Banned,
-    Unknown,
-}
-
-impl AccountErrorReason {
-    /// 返回稳定 wire 值。
-    #[must_use]
-    pub const fn as_str(self) -> &'static str {
-        match self {
-            Self::Expired => "expired",
-            Self::TokenExpired => "token_expired",
-            Self::Invalid => "invalid",
-            Self::Banned => "banned",
-            Self::Unknown => "unknown",
-        }
-    }
-
-    /// 解析稳定 wire 值。
-    #[must_use]
-    pub fn parse(value: &str) -> Option<Self> {
-        match value {
-            "expired" => Some(Self::Expired),
-            "token_expired" => Some(Self::TokenExpired),
-            "invalid" => Some(Self::Invalid),
-            "banned" => Some(Self::Banned),
-            "unknown" => Some(Self::Unknown),
-            _ => None,
-        }
-    }
-}
-
-/// 由信号派生错误原因；非错误分类（正常 / 配额耗尽 / 限流 / 停用）返回 `None`。
-///
-/// 与 [`AccountStatusSignals::derive`] 保持同一判定：`Error` 当且仅当此处返回 `Some`。
-#[must_use]
-pub fn derive_error_reason(signals: &AccountStatusSignals) -> Option<AccountErrorReason> {
-    if !signals.enabled {
-        return None;
-    }
-    match signals.availability {
-        AccountAvailability::QuotaExhausted => None,
-        AccountAvailability::Ready => signals
-            .access_token_expired
-            .then_some(AccountErrorReason::TokenExpired),
-        AccountAvailability::Expired => Some(AccountErrorReason::Expired),
-        AccountAvailability::Invalid => Some(AccountErrorReason::Invalid),
-        AccountAvailability::Banned => Some(AccountErrorReason::Banned),
-        AccountAvailability::Unknown => Some(AccountErrorReason::Unknown),
-    }
-}
+pub use gateway_core::engine::credential::{
+    AccountErrorReason, AccountStatus, AccountStatusFacts, AccountStatusProjection,
+    CredentialState, QuotaAccessState, QuotaEvidence, QuotaState, resolve_account_status,
+};
 
 /// 账号列表排序字段。
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -207,11 +66,11 @@ pub struct AccountRecord {
     pub access_token_expires_at: Option<DateTime<Utc>>,
     pub next_refresh_at: Option<DateTime<Utc>>,
     pub enabled: bool,
-    pub availability: AccountAvailability,
-    pub availability_observed_at: DateTime<Utc>,
-    /// 最近一次非 ready 状态变更的原始原因（上游错误原文 / 原因码）；恢复 ready 后清空。
+    pub credential_state: CredentialState,
+    pub credential_observed_at: DateTime<Utc>,
+    pub quota: QuotaState,
+    pub last_error_reason: Option<AccountErrorReason>,
     pub last_error_message: Option<String>,
-    pub quota_observed_at: Option<DateTime<Utc>>,
     pub created_at: DateTime<Utc>,
     pub updated_at: DateTime<Utc>,
 }
@@ -296,11 +155,18 @@ pub struct AccountUsageWindowResult {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct AccountPage {
     pub config_revision: Revision,
-    pub items: Vec<AccountRecord>,
+    pub items: Vec<AccountPageItem>,
     pub total: u64,
     pub summary: AccountSummary,
 }
 
+/// 同一状态快照下的账号事实与唯一状态投影。
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AccountPageItem {
+    pub account: AccountRecord,
+    pub projection: AccountStatusProjection,
+}
+
 /// 统一账号目录的全局状态计数，不受当前筛选和分页影响。
 ///
 /// 计数与 [`AccountStatus`] 一一对应，由 store 按派生状态聚合。
@@ -342,9 +208,7 @@ pub enum AccountConnectionTestEvent {
     Content {
         text: String,
     },
-    Completed {
-        account_status: AccountStatus,
-    },
+    Completed,
     Failed {
         message: String,
         provider_error_code: Option<String>,
@@ -352,7 +216,6 @@ pub enum AccountConnectionTestEvent {
         upstream_status: Option<u16>,
         upstream_content_type: Option<String>,
         upstream_body: Option<String>,
-        account_status: AccountStatus,
     },
 }
 
diff --git a/backend/crates/gateway-admin/src/model/observability.rs b/backend/crates/gateway-admin/src/model/observability.rs
index 018474966..00740dc09 100644
--- a/backend/crates/gateway-admin/src/model/observability.rs
+++ b/backend/crates/gateway-admin/src/model/observability.rs
@@ -439,25 +439,15 @@ pub struct RequestMetricPoint {
     pub costs: Vec<CurrencyCost>,
 }
 
-/// 账号池容量统计。
-///
-/// 首页概览的 `unavailable` 表示不可参与调度，包含配额耗尽及过期、禁用和封禁账号。
-///
-/// `quota_exhausted`（402 确认耗尽）与 `rate_limited`（429 限流中）单列，
-/// 以便状态详情展示和诊断。
+/// 账号池的统一五态统计。
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub struct AccountPoolMetrics {
     pub total: u64,
-    pub enabled: u64,
-    pub unavailable: u64,
-    pub active: u64,
-    pub rate_limited: u64,
-    pub expired: u64,
-    pub invalid: u64,
+    pub normal: u64,
     pub quota_exhausted: u64,
-    pub refreshing: Option<u64>,
+    pub rate_limited: u64,
     pub disabled: u64,
-    pub banned: u64,
+    pub error: u64,
 }
 
 /// Dashboard 中一个账号的模型级用量事实。
@@ -488,7 +478,7 @@ pub struct DashboardAccountRequestBucket {
     pub request_count: u64,
 }
 
-/// Dashboard 中一个账号的完整用量与公共状态事实。
+/// Dashboard 中一个账号的完整用量事实。
 #[derive(Debug, Clone, PartialEq)]
 pub struct DashboardAccountUsage {
     pub account_id: String,
@@ -497,8 +487,6 @@ pub struct DashboardAccountUsage {
     pub name: String,
     pub email: Option<String>,
     pub plan_type: Option<String>,
-    pub enabled: bool,
-    pub availability: String,
     pub request_count: u64,
     pub success_count: u64,
     pub input_tokens: Option<u64>,
diff --git a/backend/crates/gateway-admin/src/model/provider_credentials.rs b/backend/crates/gateway-admin/src/model/provider_credentials.rs
index 3489bb012..970068f21 100644
--- a/backend/crates/gateway-admin/src/model/provider_credentials.rs
+++ b/backend/crates/gateway-admin/src/model/provider_credentials.rs
@@ -11,10 +11,7 @@ use gateway_core::{
 
 use super::{
     AdminError, MutationActor, MutationContext, PageSize, Revision,
-    accounts::{
-        AccountAvailability, AccountErrorReason, AccountRecord, AccountStatus, AccountSummary,
-        AccountUsage,
-    },
+    accounts::{AccountRecord, AccountSummary, AccountUsage, CredentialState},
 };
 
 /// Provider-owned JSON；公共层只搬运且 Debug 不输出值。
@@ -55,24 +52,24 @@ pub struct CredentialCursor {
 /// Provider credential 列表查询。
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct CredentialListQuery {
-    pub availability: Option<CredentialAvailabilityFilter>,
+    pub credential_state: Option<CredentialStateFilter>,
     pub enabled: Option<bool>,
     pub window: CredentialListWindow,
 }
 
-/// Credential 可用性筛选；支持一个 wire 值对应多个持久状态。
+/// Credential 状态筛选。
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub enum CredentialAvailabilityFilter {
-    Exact(AccountAvailability),
-    AnyOf(Vec<AccountAvailability>),
+pub enum CredentialStateFilter {
+    Exact(CredentialState),
+    AnyOf(Vec<CredentialState>),
 }
 
-impl CredentialAvailabilityFilter {
+impl CredentialStateFilter {
     #[must_use]
-    pub fn matches(&self, availability: AccountAvailability) -> bool {
+    pub fn matches(&self, credential_state: CredentialState) -> bool {
         match self {
-            Self::Exact(expected) => *expected == availability,
-            Self::AnyOf(expected) => expected.contains(&availability),
+            Self::Exact(expected) => *expected == credential_state,
+            Self::AnyOf(expected) => expected.contains(&credential_state),
         }
     }
 }
@@ -155,8 +152,8 @@ pub struct PreparedCredentialCreate {
     pub access_token_expires_at: Option<DateTime<Utc>>,
     pub next_refresh_at: Option<DateTime<Utc>>,
     pub enabled: bool,
-    pub availability: AccountAvailability,
-    pub availability_observed_at: DateTime<Utc>,
+    pub credential_state: CredentialState,
+    pub credential_observed_at: DateTime<Utc>,
 }
 
 /// Provider 对一份导入文档的完整验证结果。
@@ -603,15 +600,31 @@ pub struct ProviderQuota {
     pub observed_at: Option<DateTime<Utc>>,
     pub refresh_token_expires_at: Option<DateTime<Utc>>,
     pub windows: Vec<ProviderQuotaWindow>,
-    /// 快照级限流事实（顶层或任一窗口触顶）；Admin 状态派生用，前端不再遍历窗口猜测。
+    /// 展示用快照级触顶事实（顶层或任一窗口触顶）；不参与账号五态派生。
     pub limit_reached: bool,
-    /// 429 临时限流（Redis 冷却）到期时间；`Some` 时账号处于临时限流，到期自动恢复。
-    /// 与 `limit_reached`（配额耗尽）是独立维度，不污染额度窗口。
-    pub rate_limited_until: Option<DateTime<Utc>>,
     pub provider_data: Option<ProviderDocument>,
 }
 
 impl ProviderQuota {
+    /// 返回账号展开面板使用的当前额度窗口用量。
+    ///
+    /// 只选择具备完整时间边界且可按账号归属的窗口；优先级与 Dashboard
+    /// 代表性额度窗口一致，同一优先级保持 Provider 投影顺序。
+    #[must_use]
+    pub fn representative_window_usage(&self) -> Option<&AccountUsage> {
+        self.windows
+            .iter()
+            .enumerate()
+            .filter(|(_, window)| {
+                window.local_usage_attribution == QuotaLocalUsageAttribution::AccountWide
+                    && window.window_seconds.is_some()
+                    && window.reset_at.is_some()
+                    && window.local_usage.is_some()
+            })
+            .min_by_key(|(index, window)| (quota_usage_priority(window), *index))
+            .and_then(|(_, window)| window.local_usage.as_ref())
+    }
+
     /// 返回 Dashboard 使用的代表性额度比例。
     ///
     /// 优先使用短周期窗口，再依次使用周、月和其它窗口；同一优先级取较高的已用比例。
@@ -703,9 +716,7 @@ impl fmt::Debug for ProviderExport {
 #[derive(Debug, Clone, PartialEq)]
 pub struct AccountDirectoryItem {
     pub account: AccountRecord,
-    pub status: AccountStatus,
-    /// `status == Error` 时的具体原因；其余状态为 `None`。
-    pub error_reason: Option<AccountErrorReason>,
+    pub projection: gateway_core::engine::credential::AccountStatusProjection,
     pub usage: Option<super::accounts::AccountUsage>,
     pub quota: ProviderQuota,
 }
diff --git a/backend/crates/gateway-admin/src/ports/store.rs b/backend/crates/gateway-admin/src/ports/store.rs
index 7e8584fac..411f0072d 100644
--- a/backend/crates/gateway-admin/src/ports/store.rs
+++ b/backend/crates/gateway-admin/src/ports/store.rs
@@ -11,7 +11,7 @@ use super::backup::BackupStorePorts;
 use crate::model::{
     MutationContext, Revision,
     accounts::{
-        AccountListQuery, AccountPage, AccountRecord, AccountUsage, AccountUsageWindowQuery,
+        AccountListQuery, AccountPage, AccountPageItem, AccountUsage, AccountUsageWindowQuery,
         AccountUsageWindowResult, DeleteAccounts, SetAccountEnabled,
     },
     auth::{AdminAuditEvent, AdminSession},
@@ -83,7 +83,7 @@ pub type AdminStoreResult<T> = Result<T, AdminStoreError>;
 pub trait AccountStore: Send + Sync {
     async fn list_accounts(&self, query: AccountListQuery) -> AdminStoreResult<AccountPage>;
 
-    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountRecord>>;
+    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountPageItem>>;
 
     async fn load_account_usage(
         &self,
diff --git a/backend/crates/gateway-admin/src/use_case/accounts.rs b/backend/crates/gateway-admin/src/use_case/accounts.rs
index 24eae9c09..d57df6043 100644
--- a/backend/crates/gateway-admin/src/use_case/accounts.rs
+++ b/backend/crates/gateway-admin/src/use_case/accounts.rs
@@ -1,6 +1,6 @@
 //! 统一账号目录与跨 Provider 动态分派。
 
-use std::{collections::BTreeMap, sync::Arc, time::SystemTime};
+use std::{collections::BTreeMap, sync::Arc};
 
 use async_trait::async_trait;
 use chrono::{Duration, Utc};
@@ -18,8 +18,7 @@ use crate::{
         AdminError, MutationContext,
         accounts::{
             AccountConnectionTestEvent, AccountConnectionTestEventStream, AccountListQuery,
-            AccountRecord, AccountStatus, AccountStatusSignals, AccountUsageWindowQuery,
-            derive_error_reason,
+            AccountPageItem, AccountUsageWindowQuery,
         },
         observability::TimeRange,
         provider_credentials::{
@@ -28,10 +27,7 @@ use crate::{
             ProviderQuotaWindow, QuotaLocalUsageAttribution,
         },
     },
-    ports::{
-        provider::ProviderAdminRegistry,
-        store::{AccountStore, SettingsStore},
-    },
+    ports::{provider::ProviderAdminRegistry, store::AccountStore},
 };
 
 use super::{
@@ -79,7 +75,6 @@ pub trait AccountsService: Send + Sync {
 
 pub(crate) struct DefaultAccountsService {
     accounts: Arc<dyn AccountStore>,
-    settings: Arc<dyn SettingsStore>,
     providers: ProviderAdminRegistry,
     snapshot: Arc<dyn SnapshotControl>,
     probe: Arc<dyn AccountProbe>,
@@ -89,14 +84,12 @@ impl DefaultAccountsService {
     #[must_use]
     pub(crate) const fn new(
         accounts: Arc<dyn AccountStore>,
-        settings: Arc<dyn SettingsStore>,
         providers: ProviderAdminRegistry,
         snapshot: Arc<dyn SnapshotControl>,
         probe: Arc<dyn AccountProbe>,
     ) -> Self {
         Self {
             accounts,
-            settings,
             providers,
             snapshot,
             probe,
@@ -106,7 +99,7 @@ impl DefaultAccountsService {
     async fn load_account(
         &self,
         account_id: &ProviderAccountId,
-    ) -> Result<AccountRecord, AdminError> {
+    ) -> Result<AccountPageItem, AdminError> {
         self.accounts
             .load_account(account_id.as_str())
             .await
@@ -119,32 +112,32 @@ impl DefaultAccountsService {
         account_id: &ProviderAccountId,
     ) -> Result<
         (
-            AccountRecord,
+            AccountPageItem,
             Arc<dyn crate::ports::provider::ProviderAdmin>,
         ),
         AdminError,
     > {
-        let account = self.load_account(account_id).await?;
+        let item = self.load_account(account_id).await?;
         let provider = self
             .providers
-            .require(&account.provider_kind)
+            .require(&item.account.provider_kind)
             .map_err(|error| map_provider_error(error, "provider account"))?;
-        Ok((account, provider))
+        Ok((item, provider))
     }
 
     async fn attach_quota_local_usage(
         &self,
-        accounts: &[AccountRecord],
+        accounts: &[AccountPageItem],
         quotas: &mut [ProviderQuota],
     ) -> Result<(), AdminError> {
         let windows = accounts
             .iter()
             .zip(quotas.iter())
-            .flat_map(|(account, quota)| {
+            .flat_map(|(item, quota)| {
                 quota
                     .windows
                     .iter()
-                    .filter_map(|window| quota_usage_window(&account.id, window))
+                    .filter_map(|window| quota_usage_window(&item.account.id, window))
             })
             .collect::<Vec<_>>();
         if windows.is_empty() {
@@ -158,12 +151,12 @@ impl DefaultAccountsService {
             .into_iter()
             .map(|result| ((result.account_id, result.key), result.usage))
             .collect::<BTreeMap<_, _>>();
-        for (account, quota) in accounts.iter().zip(quotas) {
+        for (item, quota) in accounts.iter().zip(quotas) {
             for window in &mut quota.windows {
                 if window.local_usage.is_none()
                     && window.local_usage_attribution == QuotaLocalUsageAttribution::AccountWide
                 {
-                    let key = (account.id.clone(), window.key.clone());
+                    let key = (item.account.id.clone(), window.key.clone());
                     if let Some(usage) = usage_by_window.get(&key) {
                         window.local_usage = Some(usage.clone());
                     }
@@ -178,33 +171,19 @@ impl DefaultAccountsService {
         account_id: &ProviderAccountId,
         refresh_quota: bool,
     ) -> Result<AccountDirectoryItem, AdminError> {
-        let (account, provider) = self.provider_for_account(account_id).await?;
-        let settings = self
-            .settings
-            .load_runtime_settings()
-            .await
-            .map_err(|error| map_store_error(error, "runtime settings"))?;
+        let (stored, provider) = self.provider_for_account(account_id).await?;
+        let account = &stored.account;
         let now = Utc::now();
-        let retained_range = retained_usage_range(now, settings.usage_retention_days);
         let rolling_range = TimeRange {
             start: now - Duration::hours(24),
             end: now,
         };
         let ids = vec![account.id.clone()];
-        let (usage, rolling_usage) = futures::try_join!(
-            async {
-                self.accounts
-                    .load_account_usage(retained_range, &ids)
-                    .await
-                    .map_err(|error| map_store_error(error, "account usage"))
-            },
-            async {
-                self.accounts
-                    .load_account_usage(rolling_range, &ids)
-                    .await
-                    .map_err(|error| map_store_error(error, "rolling account usage"))
-            },
-        )?;
+        let rolling_usage = self
+            .accounts
+            .load_account_usage(rolling_range, &ids)
+            .await
+            .map_err(|error| map_store_error(error, "rolling account usage"))?;
         let rolling_usage = rolling_usage.into_iter().next();
         let mut quota = provider
             .quota(ProviderQuotaRequest {
@@ -215,17 +194,15 @@ impl DefaultAccountsService {
             .await
             .map_err(|error| map_provider_error(error, "provider quota"))?;
         self.attach_quota_local_usage(
-            std::slice::from_ref(&account),
+            std::slice::from_ref(&stored),
             std::slice::from_mut(&mut quota),
         )
         .await?;
-        let signals = account_signals(&account, &quota, now);
-        let error_reason = derive_error_reason(&signals);
+        let usage = quota.representative_window_usage().cloned();
         Ok(AccountDirectoryItem {
-            status: signals.derive(),
-            error_reason,
-            usage: usage.into_iter().next(),
-            account,
+            projection: stored.projection,
+            usage,
+            account: stored.account,
             quota,
         })
     }
@@ -234,13 +211,12 @@ impl DefaultAccountsService {
 #[async_trait]
 impl AccountsService for DefaultAccountsService {
     async fn list(&self, query: AccountListQuery) -> Result<AccountDirectoryPage, AdminError> {
-        let (page, settings) = futures::try_join!(
-            self.accounts.list_accounts(query),
-            self.settings.load_runtime_settings(),
-        )
-        .map_err(|error| map_store_error(error, "account directory"))?;
+        let page = self
+            .accounts
+            .list_accounts(query)
+            .await
+            .map_err(|error| map_store_error(error, "account directory"))?;
         let now = Utc::now();
-        let retained_range = retained_usage_range(now, settings.usage_retention_days);
         let rolling_range = TimeRange {
             start: now - Duration::hours(24),
             end: now,
@@ -248,22 +224,19 @@ impl AccountsService for DefaultAccountsService {
         let ids = page
             .items
             .iter()
-            .map(|account| account.id.clone())
+            .map(|item| item.account.id.clone())
             .collect::<Vec<_>>();
-        let (usage, rolling_usage) = futures::try_join!(
-            self.accounts.load_account_usage(retained_range, &ids),
-            self.accounts.load_account_usage(rolling_range, &ids),
-        )
-        .map_err(|error| map_store_error(error, "account usage"))?;
-        let usage = usage
-            .into_iter()
-            .map(|usage| (usage.account_id.clone(), usage))
-            .collect::<BTreeMap<_, _>>();
+        let rolling_usage = self
+            .accounts
+            .load_account_usage(rolling_range, &ids)
+            .await
+            .map_err(|error| map_store_error(error, "rolling account usage"))?;
         let rolling_usage = rolling_usage
             .into_iter()
             .map(|usage| (usage.account_id.clone(), usage))
             .collect::<BTreeMap<_, _>>();
-        let mut quotas = futures::future::join_all(page.items.iter().map(|account| async {
+        let mut quotas = futures::future::join_all(page.items.iter().map(|item| async {
+            let account = &item.account;
             let account_id = ProviderAccountId::new(account.id.clone())
                 .map_err(|_| AdminError::invalid("Invalid provider account ID"))?;
             // 单个账号的 quota 投影失败（Provider 未注册或 quota 读取失败）不拖垮整页：
@@ -307,14 +280,12 @@ impl AccountsService for DefaultAccountsService {
             .items
             .into_iter()
             .zip(quotas)
-            .map(|(account, quota)| {
-                let signals = account_signals(&account, &quota, now);
-                let error_reason = derive_error_reason(&signals);
+            .map(|(item, quota)| {
+                let usage = quota.representative_window_usage().cloned();
                 AccountDirectoryItem {
-                    status: signals.derive(),
-                    error_reason,
-                    usage: usage.get(&account.id).cloned(),
-                    account,
+                    usage,
+                    account: item.account,
+                    projection: item.projection,
                     quota,
                 }
             })
@@ -342,7 +313,7 @@ impl AccountsService for DefaultAccountsService {
         for account_id in account_ids {
             let account = self.load_account(&account_id).await?;
             grouped
-                .entry(account.provider_kind)
+                .entry(account.account.provider_kind)
                 .or_default()
                 .push(account_id);
         }
@@ -385,7 +356,8 @@ impl AccountsService for DefaultAccountsService {
         context: &MutationContext,
         account_id: ProviderAccountId,
     ) -> Result<AccountRefreshResult, AdminError> {
-        let (account, provider) = self.provider_for_account(&account_id).await?;
+        let (stored, provider) = self.provider_for_account(&account_id).await?;
+        let account = stored.account;
         let prepared = provider
             .prepare_refresh(PrepareCredentialRefresh {
                 account: account.clone(),
@@ -436,8 +408,8 @@ impl AccountsService for DefaultAccountsService {
         account_id: ProviderAccountId,
         upstream_model: UpstreamModelId,
     ) -> Result<AccountConnectionTestEventStream, AdminError> {
-        let (account, provider) = self.provider_for_account(&account_id).await?;
-        let initial_status = account_status(&account, false, Utc::now());
+        let (stored, provider) = self.provider_for_account(&account_id).await?;
+        let account = stored.account;
         let model = upstream_model.as_str().to_owned();
         let operation = provider
             .connection_test_operation(&upstream_model, CONNECTION_TEST_INPUT)
@@ -454,8 +426,6 @@ impl AccountsService for DefaultAccountsService {
             },
         ];
         let probe = Arc::clone(&self.probe);
-        let accounts = Arc::clone(&self.accounts);
-        let stored_account_id = account.id.clone();
         let terminal = futures::stream::once(async move {
             let result = probe
                 .probe(AccountProbeRequest {
@@ -465,22 +435,12 @@ impl AccountsService for DefaultAccountsService {
                     operation,
                 })
                 .await;
-            let status = accounts
-                .load_account(&stored_account_id)
-                .await
-                .ok()
-                .flatten()
-                .map_or(initial_status, |account| {
-                    account_status(&account, false, Utc::now())
-                });
             match result {
                 Ok(result) => result
                     .text
                     .into_iter()
                     .map(|text| AccountConnectionTestEvent::Content { text })
-                    .chain(std::iter::once(AccountConnectionTestEvent::Completed {
-                        account_status: status,
-                    }))
+                    .chain(std::iter::once(AccountConnectionTestEvent::Completed))
                     .collect(),
                 Err(error) => {
                     let upstream_status = error
@@ -506,7 +466,6 @@ impl AccountsService for DefaultAccountsService {
                         upstream_status,
                         upstream_content_type,
                         upstream_body,
-                        account_status: status,
                     }]
                 }
             }
@@ -523,49 +482,10 @@ fn empty_quota() -> ProviderQuota {
         refresh_token_expires_at: None,
         windows: Vec::new(),
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     }
 }
 
-/// 构造状态派生所需的信号快照。
-fn account_signals(
-    account: &AccountRecord,
-    quota: &ProviderQuota,
-    now: chrono::DateTime<Utc>,
-) -> AccountStatusSignals {
-    AccountStatusSignals {
-        enabled: account.enabled,
-        availability: account.availability,
-        access_token_expired: account
-            .access_token_expires_at
-            .is_some_and(|expires_at| expires_at <= now),
-        quota_limit_reached: quota.limit_reached,
-        rate_limited_until: quota.rate_limited_until.map(SystemTime::from),
-    }
-}
-
-/// 账号运营分类（互斥展示状态）。
-fn account_status(
-    account: &AccountRecord,
-    quota_limit_reached: bool,
-    now: chrono::DateTime<Utc>,
-) -> AccountStatus {
-    let quota = ProviderQuota {
-        limit_reached: quota_limit_reached,
-        ..empty_quota()
-    };
-    account_signals(account, &quota, now).derive()
-}
-
-fn retained_usage_range(now: chrono::DateTime<Utc>, retention_days: u32) -> TimeRange {
-    // 账号留存投影是内部查询，不受外部观测接口 366 天上限约束。
-    TimeRange {
-        start: now - Duration::days(i64::from(retention_days)),
-        end: now,
-    }
-}
-
 fn quota_usage_window(
     account_id: &str,
     window: &ProviderQuotaWindow,
diff --git a/backend/crates/gateway-admin/src/use_case/observability.rs b/backend/crates/gateway-admin/src/use_case/observability.rs
index eaa809890..a116f81b6 100644
--- a/backend/crates/gateway-admin/src/use_case/observability.rs
+++ b/backend/crates/gateway-admin/src/use_case/observability.rs
@@ -127,7 +127,7 @@ impl ObservabilityService for DefaultObservabilityService {
         let max_concurrent_per_account = u64::from(settings.max_concurrent_per_account);
         let active_accounts = runtime_slots
             .as_ref()
-            .map_or(observation.provider_accounts.active, |slots| {
+            .map_or(observation.provider_accounts.normal, |slots| {
                 slots.active_accounts
             });
         let total_slots = active_accounts.saturating_mul(max_concurrent_per_account);
@@ -484,8 +484,7 @@ impl DefaultObservabilityService {
         });
         let quota_used = futures::future::join_all(quota_reads).await;
         for (account, used_percent) in accounts.iter_mut().zip(quota_used) {
-            account.quota_used_percent = used_percent
-                .or_else(|| (account.availability == "quota_exhausted").then_some(100.0));
+            account.quota_used_percent = used_percent;
         }
     }
 
diff --git a/backend/crates/gateway-admin/tests/main.rs b/backend/crates/gateway-admin/tests/main.rs
index ee8b8d334..735ff1fe1 100644
--- a/backend/crates/gateway-admin/tests/main.rs
+++ b/backend/crates/gateway-admin/tests/main.rs
@@ -129,7 +129,6 @@ fn representative_quota_should_prefer_short_window_and_highest_usage() {
             quota_window("shortTerm", Some(14_400), Some(45.0)),
         ],
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     };
 
diff --git a/backend/crates/gateway-admin/tests/use_case/accounts.rs b/backend/crates/gateway-admin/tests/use_case/accounts.rs
index 4f1e97377..43b4d1fec 100644
--- a/backend/crates/gateway-admin/tests/use_case/accounts.rs
+++ b/backend/crates/gateway-admin/tests/use_case/accounts.rs
@@ -5,7 +5,10 @@ use chrono::{TimeDelta, Utc};
 use futures::{StreamExt as _, future::BoxFuture};
 use gateway_core::{
     engine::{
-        credential::{OpaqueProviderData, ProviderAccountId},
+        credential::{
+            AccountStatusFacts, CredentialState, OpaqueProviderData, ProviderAccountId,
+            QuotaEvidence, QuotaState, resolve_account_status,
+        },
         probe::{AccountProbe, AccountProbeError, AccountProbeRequest, AccountProbeResult},
     },
     error::{ClientVisibleUpstreamError, GatewayError, GatewayErrorKind},
@@ -18,7 +21,7 @@ use gateway_admin::{
     model::{
         AdminError, MutationContext, Revision,
         accounts::{
-            AccountAvailability, AccountConnectionTestEvent, AccountListQuery, AccountPage,
+            AccountConnectionTestEvent, AccountListQuery, AccountPage, AccountPageItem,
             AccountRecord, AccountSummary, AccountUsage, AccountUsageWindowQuery,
             AccountUsageWindowResult, DeleteAccounts, SetAccountEnabled,
         },
@@ -378,6 +381,7 @@ pub(super) struct FakeAccountStore {
     fail_commit: Mutex<bool>,
     audit_requests: Mutex<Vec<String>>,
     quota_window_usage: Mutex<Vec<AccountUsageWindowResult>>,
+    quota_window_queries: Mutex<Vec<AccountUsageWindowQuery>>,
 }
 
 impl FakeAccountStore {
@@ -393,6 +397,7 @@ impl FakeAccountStore {
             fail_commit: Mutex::new(false),
             audit_requests: Mutex::new(Vec::new()),
             quota_window_usage: Mutex::new(Vec::new()),
+            quota_window_queries: Mutex::new(Vec::new()),
         })
     }
 
@@ -408,6 +413,13 @@ impl FakeAccountStore {
         *self.quota_window_usage.lock().expect("quota window usage") = usage;
     }
 
+    fn quota_window_queries(&self) -> Vec<AccountUsageWindowQuery> {
+        self.quota_window_queries
+            .lock()
+            .expect("quota window queries")
+            .clone()
+    }
+
     pub(super) fn set_accounts(&self, accounts: Vec<AccountRecord>) {
         *self.accounts.lock().expect("accounts") = accounts;
     }
@@ -438,6 +450,22 @@ impl FakeAccountStore {
             .expect("audit requests")
             .push(context.request_id.clone());
     }
+
+    fn page_item(account: AccountRecord) -> AccountPageItem {
+        let facts = AccountStatusFacts {
+            enabled: account.enabled,
+            credential_state: account.credential_state,
+            access_token_expires_at: account.access_token_expires_at.map(Into::into),
+            quota: account.quota,
+            rate_limited_until: None,
+            last_error_reason: account.last_error_reason,
+            last_error_message: account.last_error_message.clone(),
+        };
+        AccountPageItem {
+            account,
+            projection: resolve_account_status(&facts, std::time::SystemTime::now()),
+        }
+    }
 }
 
 #[async_trait]
@@ -445,12 +473,13 @@ impl AccountStore for FakeAccountStore {
     async fn list_accounts(&self, _: AccountListQuery) -> AdminStoreResult<AccountPage> {
         self.record("store.list_accounts");
         let accounts = self.accounts.lock().expect("accounts").clone();
+        let total = accounts.len() as u64;
         Ok(AccountPage {
             config_revision: revision(1),
-            items: accounts.clone(),
-            total: accounts.len() as u64,
+            items: accounts.into_iter().map(Self::page_item).collect(),
+            total,
             summary: AccountSummary {
-                total: accounts.len() as u64,
+                total,
                 normal: 1,
                 quota_exhausted: 0,
                 rate_limited: 0,
@@ -460,7 +489,7 @@ impl AccountStore for FakeAccountStore {
         })
     }
 
-    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountRecord>> {
+    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountPageItem>> {
         self.record("store.load_account");
         // probe 后的账号状态覆盖只对同一 id 生效；其余按账号列表查询。
         let account = self
@@ -477,7 +506,7 @@ impl AccountStore for FakeAccountStore {
                     .find(|account| account.id == account_id)
                     .cloned()
             });
-        Ok(account)
+        Ok(account.map(Self::page_item))
     }
 
     async fn load_account_usage(
@@ -490,8 +519,12 @@ impl AccountStore for FakeAccountStore {
 
     async fn load_account_usage_by_windows(
         &self,
-        _: &[AccountUsageWindowQuery],
+        windows: &[AccountUsageWindowQuery],
     ) -> AdminStoreResult<Vec<AccountUsageWindowResult>> {
+        *self
+            .quota_window_queries
+            .lock()
+            .expect("quota window queries") = windows.to_vec();
         Ok(self
             .quota_window_usage
             .lock()
@@ -815,7 +848,11 @@ fn provider_registry_should_reject_duplicate_kind() {
 async fn connection_test_should_probe_unavailable_account() {
     let provider = FakeProviderAdmin::new("xai", events());
     let mut account = account_record("xai");
-    account.availability = AccountAvailability::QuotaExhausted;
+    account.quota = QuotaState::exhausted(
+        QuotaEvidence::UsageLimitReached,
+        std::time::SystemTime::now(),
+        None,
+    );
     let store = FakeAccountStore::with_account(account, events());
     let services =
         accounts_service_with_probe(provider, store, Arc::new(FailingAccountProbe)).await;
@@ -837,7 +874,6 @@ async fn connection_test_should_probe_unavailable_account() {
             message,
             provider_error_code: Some(code),
             provider_error_type: Some(error_type),
-            account_status: gateway_admin::model::accounts::AccountStatus::QuotaExhausted,
             ..
         }) if message == "included usage exhausted"
             && code == "usage_exhausted"
@@ -846,7 +882,7 @@ async fn connection_test_should_probe_unavailable_account() {
 }
 
 #[tokio::test]
-async fn connection_test_rate_limited_probe_preserves_normal_account_status() {
+async fn connection_test_rate_limited_probe_returns_provider_failure() {
     let events = events();
     let provider = FakeProviderAdmin::new("xai", events.clone());
     let store = FakeAccountStore::new("xai", events);
@@ -869,9 +905,10 @@ async fn connection_test_rate_limited_probe_preserves_normal_account_status() {
     assert!(matches!(
         events.last(),
         Some(AccountConnectionTestEvent::Failed {
-            account_status: gateway_admin::model::accounts::AccountStatus::Normal,
+            message,
             ..
         })
+        if message == "xAI free model quota is exhausted"
     ));
 }
 
@@ -897,10 +934,7 @@ async fn connection_test_should_preserve_disabled_account_status() {
 
     assert!(matches!(
         events.last(),
-        Some(AccountConnectionTestEvent::Failed {
-            account_status: gateway_admin::model::accounts::AccountStatus::Disabled,
-            ..
-        })
+        Some(AccountConnectionTestEvent::Failed { .. })
     ));
 }
 
@@ -949,7 +983,7 @@ async fn accounts_refresh_should_keep_guard_through_store_commit() {
     assert_eq!(result.config_revision, revision(2));
     assert_eq!(result.account.account.provider_kind.as_str(), "openai");
     assert_eq!(
-        result.account.status,
+        result.account.projection.status,
         gateway_admin::model::accounts::AccountStatus::Normal
     );
 
@@ -990,7 +1024,7 @@ async fn accounts_list_should_return_complete_directory_semantics() {
     let account = page.items.first().expect("account item");
     assert_eq!(account.account.provider_kind.as_str(), "openai");
     assert_eq!(
-        account.status,
+        account.projection.status,
         gateway_admin::model::accounts::AccountStatus::Normal
     );
 }
@@ -1016,7 +1050,6 @@ async fn accounts_list_should_degrade_quota_failure_to_empty_window_without_drop
             provider_data: None,
         }],
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     });
     let failing = FakeProviderAdmin::new("xai", events.clone());
@@ -1064,10 +1097,14 @@ async fn accounts_list_should_degrade_quota_failure_to_empty_window_without_drop
 }
 
 #[tokio::test]
-async fn accounts_list_should_prefer_quota_exhaustion_over_stale_token_expiry() {
+async fn accounts_list_should_prefer_credential_error_over_quota_exhaustion() {
     let provider = FakeProviderAdmin::new("openai", events());
     let mut account = account_record("openai");
-    account.availability = AccountAvailability::QuotaExhausted;
+    account.quota = QuotaState::exhausted(
+        QuotaEvidence::ProviderDenied,
+        std::time::SystemTime::now(),
+        None,
+    );
     account.access_token_expires_at = Some(Utc::now() - TimeDelta::minutes(5));
     let store = FakeAccountStore::with_account(account, events());
 
@@ -1086,17 +1123,17 @@ async fn accounts_list_should_prefer_quota_exhaustion_over_stale_token_expiry()
         .expect("usage-limited account directory");
 
     assert_eq!(
-        page.items.first().expect("account item").status,
-        gateway_admin::model::accounts::AccountStatus::QuotaExhausted,
+        page.items.first().expect("account item").projection.status,
+        gateway_admin::model::accounts::AccountStatus::Error,
     );
 }
 
 #[tokio::test]
-async fn accounts_list_should_map_unknown_availability_to_error_not_normal() {
+async fn accounts_list_should_map_unknown_credential_to_error_not_normal() {
     // Unknown 不可调度，Admin 不得显示为 normal。
     let provider = FakeProviderAdmin::new("openai", events());
     let mut account = account_record("openai");
-    account.availability = AccountAvailability::Unknown;
+    account.credential_state = CredentialState::Unknown;
     let store = FakeAccountStore::with_account(account, events());
 
     let page = accounts_service(provider, store)
@@ -1114,15 +1151,13 @@ async fn accounts_list_should_map_unknown_availability_to_error_not_normal() {
         .expect("unknown account directory");
 
     assert_eq!(
-        page.items.first().expect("account item").status,
+        page.items.first().expect("account item").projection.status,
         gateway_admin::model::accounts::AccountStatus::Error,
     );
 }
 
 #[tokio::test]
-async fn accounts_list_should_map_rate_limited_from_quota_limit_reached() {
-    // ready + 快照级 quota.limitReached → quota_exhausted（配额耗尽）；
-    // rate_limited 只来自 ProviderQuota.rate_limited_until（429 Redis 冷却）。
+async fn accounts_list_should_not_derive_rate_limited_from_provider_quota_view() {
     let provider = FakeProviderAdmin::new("openai", events());
     provider.set_quota(ProviderQuota {
         observed_at: Some(Utc::now()),
@@ -1141,7 +1176,6 @@ async fn accounts_list_should_map_rate_limited_from_quota_limit_reached() {
             provider_data: None,
         }],
         limit_reached: true,
-        rate_limited_until: Some(Utc::now() + TimeDelta::minutes(5)),
         provider_data: None,
     });
     let store = FakeAccountStore::new("openai", events());
@@ -1158,17 +1192,16 @@ async fn accounts_list_should_map_rate_limited_from_quota_limit_reached() {
             sort: None,
         })
         .await
-        .expect("rate limited account directory");
+        .expect("account directory with display quota cooldown");
 
     assert_eq!(
-        page.items.first().expect("account item").status,
-        gateway_admin::model::accounts::AccountStatus::RateLimited,
+        page.items.first().expect("account item").projection.status,
+        gateway_admin::model::accounts::AccountStatus::Normal,
     );
 }
 
 #[tokio::test]
-async fn accounts_list_should_map_quota_exhausted_when_only_limit_reached() {
-    // ready + 快照级 quota.limitReached、无 429 冷却 → quota_exhausted。
+async fn accounts_list_should_not_derive_exhaustion_from_provider_quota_view() {
     let provider = FakeProviderAdmin::new("openai", events());
     provider.set_quota(ProviderQuota {
         observed_at: Some(Utc::now()),
@@ -1187,7 +1220,6 @@ async fn accounts_list_should_map_quota_exhausted_when_only_limit_reached() {
             provider_data: None,
         }],
         limit_reached: true,
-        rate_limited_until: None,
         provider_data: None,
     });
     let store = FakeAccountStore::new("openai", events());
@@ -1204,11 +1236,11 @@ async fn accounts_list_should_map_quota_exhausted_when_only_limit_reached() {
             sort: None,
         })
         .await
-        .expect("quota exhausted account directory");
+        .expect("account directory with display quota limit");
 
     assert_eq!(
-        page.items.first().expect("account item").status,
-        gateway_admin::model::accounts::AccountStatus::QuotaExhausted,
+        page.items.first().expect("account item").projection.status,
+        gateway_admin::model::accounts::AccountStatus::Normal,
     );
 }
 
@@ -1233,7 +1265,6 @@ async fn accounts_list_should_attach_local_usage_to_quota_windows() {
             provider_data: None,
         }],
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     });
     let store = FakeAccountStore::new("openai", events());
@@ -1243,7 +1274,7 @@ async fn accounts_list_should_attach_local_usage_to_quota_windows() {
         usage: quota_local_usage("acct_test", 4_330_000),
     }]);
 
-    let page = accounts_service(provider, store)
+    let page = accounts_service(provider, store.clone())
         .await
         .accounts()
         .list(AccountListQuery {
@@ -1257,11 +1288,23 @@ async fn accounts_list_should_attach_local_usage_to_quota_windows() {
         .await
         .expect("quota window usage");
 
-    let usage = page.items[0].quota.windows[0]
+    let item = &page.items[0];
+    let usage = item.quota.windows[0]
         .local_usage
         .as_ref()
         .expect("quota window local usage");
     assert_eq!(usage.total_tokens, Some(4_330_000));
+    assert_eq!(
+        item.usage.as_ref().and_then(|usage| usage.total_tokens),
+        Some(4_330_000),
+    );
+
+    let queries = store.quota_window_queries();
+    assert_eq!(queries.len(), 1);
+    assert_eq!(queries[0].account_id, "acct_test");
+    assert_eq!(queries[0].key, "primary");
+    assert_eq!(queries[0].range.start, reset_at - TimeDelta::hours(5));
+    assert_eq!(queries[0].range.end, reset_at);
 }
 
 #[tokio::test]
@@ -1300,7 +1343,6 @@ async fn accounts_list_should_not_attach_account_usage_to_model_specific_quota_w
             },
         ],
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     });
     let store = FakeAccountStore::new("openai", events());
@@ -1352,6 +1394,13 @@ async fn accounts_list_should_not_attach_account_usage_to_model_specific_quota_w
             ("codex-bengalfox-primary", None),
         ],
     );
+    assert_eq!(
+        page.items[0]
+            .usage
+            .as_ref()
+            .and_then(|usage| usage.total_tokens),
+        Some(12_818_806),
+    );
 }
 
 #[tokio::test]
@@ -1432,7 +1481,6 @@ fn empty_quota() -> ProviderQuota {
         refresh_token_expires_at: None,
         windows: Vec::new(),
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     }
 }
@@ -1476,10 +1524,11 @@ pub(super) fn account_record(kind: &str) -> AccountRecord {
         access_token_expires_at: Some(now + TimeDelta::hours(1)),
         next_refresh_at: Some(now + TimeDelta::minutes(30)),
         enabled: true,
-        availability: AccountAvailability::Ready,
-        availability_observed_at: now,
+        credential_state: CredentialState::Ready,
+        credential_observed_at: now,
+        quota: QuotaState::allowed(now.into()),
+        last_error_reason: None,
         last_error_message: None,
-        quota_observed_at: None,
         created_at: now,
         updated_at: now,
     }
@@ -1513,8 +1562,8 @@ fn prepared_create_with_id(
         access_token_expires_at: Some(now + TimeDelta::hours(1)),
         next_refresh_at: Some(now + TimeDelta::minutes(30)),
         enabled: true,
-        availability: AccountAvailability::Ready,
-        availability_observed_at: now,
+        credential_state: CredentialState::Ready,
+        credential_observed_at: now,
     }
 }
 
@@ -1597,9 +1646,7 @@ impl AccountProbe for FreeModelQuotaProbe {
         _: AccountProbeRequest,
     ) -> BoxFuture<'_, Result<AccountProbeResult, AccountProbeError>> {
         Box::pin(async move {
-            let mut account = account_record("xai");
-            account.availability = AccountAvailability::Ready;
-            self.store.set_account_after_probe(account);
+            self.store.set_account_after_probe(account_record("xai"));
             Err(GatewayError::new(
                 GatewayErrorKind::RateLimited,
                 "xAI free model quota is exhausted",
diff --git a/backend/crates/gateway-admin/tests/use_case/mod.rs b/backend/crates/gateway-admin/tests/use_case/mod.rs
index 576ff5ae5..c7b1b196e 100644
--- a/backend/crates/gateway-admin/tests/use_case/mod.rs
+++ b/backend/crates/gateway-admin/tests/use_case/mod.rs
@@ -20,7 +20,7 @@ use gateway_admin::{
     model::{
         MutationContext, Revision,
         accounts::{
-            AccountListQuery, AccountPage, AccountRecord, AccountUsage, AccountUsageWindowQuery,
+            AccountListQuery, AccountPage, AccountUsage, AccountUsageWindowQuery,
             AccountUsageWindowResult, DeleteAccounts, SetAccountEnabled,
         },
         auth::{AdminAuditEvent, AdminSession},
@@ -240,7 +240,10 @@ impl AccountStore for UnavailableStore {
         Err(unavailable("accounts"))
     }
 
-    async fn load_account(&self, _: &str) -> AdminStoreResult<Option<AccountRecord>> {
+    async fn load_account(
+        &self,
+        _: &str,
+    ) -> AdminStoreResult<Option<gateway_admin::model::accounts::AccountPageItem>> {
         Err(unavailable("account"))
     }
 
diff --git a/backend/crates/gateway-api/src/admin/accounts.rs b/backend/crates/gateway-api/src/admin/accounts.rs
index 7d0fa5ac0..254f3b62f 100644
--- a/backend/crates/gateway-api/src/admin/accounts.rs
+++ b/backend/crates/gateway-api/src/admin/accounts.rs
@@ -37,7 +37,7 @@ use gateway_core::{
 use serde::{Deserialize, Serialize};
 use serde_json::{Map, Value};
 
-use super::presenter::{format_compact_number, format_number};
+use super::presenter::{format_compact_number, format_decimal_currency, format_number};
 use super::{
     AdminAuth, AdminEnvelope, AdminError, AdminResponse, AdminSessionState, PageMeta,
     WireValidationError,
@@ -185,12 +185,10 @@ pub struct AccountView {
     pub authentication_kind: String,
     pub has_refresh_token: bool,
     pub status: String,
-    pub display_status: String,
     /// `status == "error"` 时的具体原因；其余状态为 `null`。
     pub error_reason: Option<String>,
     /// 最近一次失败的上游错误描述；仅错误状态存在。
     pub error_message: Option<String>,
-    pub availability: String,
     pub enabled: bool,
     pub access_token_expires_at: Option<String>,
     pub access_token_expires_at_display: Option<String>,
@@ -522,10 +520,9 @@ impl From<DomainConnectionTestEvent> for AccountConnectionTestEvent {
             DomainConnectionTestEvent::Content { text } => {
                 serde_json::json!({ "type": "content", "text": text })
             }
-            DomainConnectionTestEvent::Completed { account_status } => serde_json::json!({
+            DomainConnectionTestEvent::Completed => serde_json::json!({
                 "type": "test_complete",
-                "success": true,
-                "accountStatus": account_status.as_str()
+                "success": true
             }),
             DomainConnectionTestEvent::Failed {
                 message,
@@ -534,7 +531,6 @@ impl From<DomainConnectionTestEvent> for AccountConnectionTestEvent {
                 upstream_status,
                 upstream_content_type,
                 upstream_body,
-                account_status,
             } => serde_json::json!({
                 "type": "error",
                 "error": message,
@@ -542,8 +538,7 @@ impl From<DomainConnectionTestEvent> for AccountConnectionTestEvent {
                 "providerErrorType": provider_error_type,
                 "upstreamStatus": upstream_status,
                 "upstreamContentType": upstream_content_type,
-                "upstreamBody": upstream_body,
-                "accountStatus": account_status.as_str()
+                "upstreamBody": upstream_body
             }),
         };
         Self { data }
@@ -1365,16 +1360,16 @@ fn account_models_data(result: ProviderModels) -> AccountModelsData {
 fn account_view(item: AccountDirectoryItem, now: DateTime<Utc>) -> AccountView {
     let AccountDirectoryItem {
         account,
-        status,
-        error_reason,
+        projection,
         usage,
         quota,
     } = item;
-    let status = status.as_str().to_owned();
+    let status = projection.status.as_str().to_owned();
+    let rate_limited_until = projection.rate_limited_until.map(DateTime::<Utc>::from);
     let expires_at = account.access_token_expires_at.as_ref().map(china_rfc3339);
     let added_at = china_rfc3339(&account.created_at);
     let updated_at = china_rfc3339(&account.updated_at);
-    let (quota, refresh_token_expires_at) = account_quota_view(quota, now);
+    let (quota, refresh_token_expires_at) = account_quota_view(quota, rate_limited_until, now);
     AccountView {
         id: account.id.clone(),
         name: account.name,
@@ -1387,11 +1382,11 @@ fn account_view(item: AccountDirectoryItem, now: DateTime<Utc>) -> AccountView {
         plan_type: account.plan_type,
         authentication_kind: account.authentication_kind,
         has_refresh_token: account.has_refresh_token,
-        status: status.clone(),
-        display_status: status,
-        error_reason: error_reason.map(|reason| reason.as_str().to_owned()),
-        error_message: account.last_error_message,
-        availability: account.availability.as_str().to_owned(),
+        status,
+        error_reason: projection
+            .error_reason
+            .map(|reason| reason.as_str().to_owned()),
+        error_message: projection.error_message,
         enabled: account.enabled,
         access_token_expires_at: expires_at,
         access_token_expires_at_display: account
@@ -1411,6 +1406,7 @@ fn account_view(item: AccountDirectoryItem, now: DateTime<Utc>) -> AccountView {
 
 fn account_quota_view(
     quota: ProviderQuota,
+    rate_limited_until: Option<DateTime<Utc>>,
     now: DateTime<Utc>,
 ) -> (AccountQuotaView, Option<String>) {
     let refresh_token_expires_at = quota
@@ -1420,7 +1416,7 @@ fn account_quota_view(
         .observed_at
         .map_or_else(|| "—".to_owned(), |value| relative_time(value, now));
     let windows = quota.windows.into_iter().map(quota_window_view).collect();
-    let rate_limited_until = quota.rate_limited_until.map(|until| china_datetime(&until));
+    let rate_limited_until = rate_limited_until.map(|until| china_datetime(&until));
     (
         AccountQuotaView {
             refreshed_at_display,
@@ -1590,7 +1586,7 @@ fn account_model_usage_view(usage: AccountModelUsage, now: DateTime<Utc>) -> Mod
         billing_amount_usd: usd.map(|cost| cost.amount.as_str().to_owned()),
         billing_amount_usd_display: usd.map_or_else(
             || "—".to_owned(),
-            |cost| format!("${}", cost.amount.as_str()),
+            |cost| format_decimal_currency(cost.amount.as_str(), "USD"),
         ),
         cost_estimate_status: cost_estimate_status.to_owned(),
         known_cost_count: known_count,
diff --git a/backend/crates/gateway-api/src/admin/observability/mod.rs b/backend/crates/gateway-api/src/admin/observability/mod.rs
index c1cfceec5..5c917eab5 100644
--- a/backend/crates/gateway-api/src/admin/observability/mod.rs
+++ b/backend/crates/gateway-api/src/admin/observability/mod.rs
@@ -15,7 +15,7 @@ use gateway_admin::model::{PageSize as DomainPageSize, observability as domain};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
-use super::presenter::{format_compact_number, format_number};
+use super::presenter::{format_compact_number, format_decimal_currency, format_number};
 use super::{
     AdminAuth, AdminEnvelope, AdminError, AdminResponse, AdminSessionState, PageMeta,
     WireValidationError, wire::map_admin_service_error,
diff --git a/backend/crates/gateway-api/src/admin/observability/presenter.rs b/backend/crates/gateway-api/src/admin/observability/presenter.rs
index 820e542e2..17dbaebb0 100644
--- a/backend/crates/gateway-api/src/admin/observability/presenter.rs
+++ b/backend/crates/gateway-api/src/admin/observability/presenter.rs
@@ -127,20 +127,6 @@ pub(crate) fn token_details(record: &domain::UsageRecord) -> TokenDetailsView {
     }
 }
 
-pub(crate) fn format_decimal_currency(amount: &str, currency: &str) -> String {
-    if currency == "USD" {
-        let value = amount.parse::<f64>().map_or(0.0, |value| value);
-        let precision = if value != 0.0 && value.abs() < 0.01 {
-            4
-        } else {
-            2
-        };
-        format!("${value:.precision$}")
-    } else {
-        format!("{currency} {amount}")
-    }
-}
-
 pub(crate) fn format_money(cost: &domain::CurrencyCost) -> String {
     format_decimal_currency(cost.amount.as_str(), &cost.currency)
 }
@@ -747,10 +733,16 @@ pub(crate) fn dashboard_view(
             credentials: DashboardCredentialsCardView {
                 total: format_compact_number(provider_accounts.total),
                 total_value: provider_accounts.total,
-                available: format_compact_number(provider_accounts.active),
-                available_value: provider_accounts.active,
-                unavailable: format_compact_number(provider_accounts.unavailable),
-                unavailable_value: provider_accounts.unavailable,
+                available: format_compact_number(provider_accounts.normal),
+                available_value: provider_accounts.normal,
+                unavailable: format_compact_number(
+                    provider_accounts
+                        .total
+                        .saturating_sub(provider_accounts.normal),
+                ),
+                unavailable_value: provider_accounts
+                    .total
+                    .saturating_sub(provider_accounts.normal),
             },
             traffic: DashboardTrafficCardView {
                 today_requests: format_compact_number(today.request_count),
@@ -783,14 +775,11 @@ pub(crate) fn dashboard_view(
         usage_records: recent_requests.into_iter().map(usage_record_view).collect(),
         pool_summary: DashboardPoolSummaryView {
             total: provider_accounts.total,
-            active: provider_accounts.active,
-            rate_limited: provider_accounts.rate_limited,
-            expired: provider_accounts.expired,
-            invalid: provider_accounts.invalid,
+            normal: provider_accounts.normal,
             quota_exhausted: provider_accounts.quota_exhausted,
-            refreshing: provider_accounts.refreshing,
+            rate_limited: provider_accounts.rate_limited,
             disabled: provider_accounts.disabled,
-            banned: provider_accounts.banned,
+            error: provider_accounts.error,
         },
         capacity_info: DashboardCapacityInfoView {
             max_concurrent_per_account: capacity.max_concurrent_per_account,
diff --git a/backend/crates/gateway-api/src/admin/observability/wire.rs b/backend/crates/gateway-api/src/admin/observability/wire.rs
index 04a944ae1..f91fbc86f 100644
--- a/backend/crates/gateway-api/src/admin/observability/wire.rs
+++ b/backend/crates/gateway-api/src/admin/observability/wire.rs
@@ -347,14 +347,11 @@ pub struct DashboardAccountRequestBucketView {
 #[serde(rename_all = "camelCase")]
 pub struct DashboardPoolSummaryView {
     pub total: u64,
-    pub active: u64,
-    pub rate_limited: u64,
-    pub expired: u64,
-    pub invalid: u64,
+    pub normal: u64,
     pub quota_exhausted: u64,
-    pub refreshing: Option<u64>,
+    pub rate_limited: u64,
     pub disabled: u64,
-    pub banned: u64,
+    pub error: u64,
 }
 
 /// 同 target 账号调度容量；Redis 未提供聚合事实时运行中槽位保持空值。
diff --git a/backend/crates/gateway-api/src/admin/presenter.rs b/backend/crates/gateway-api/src/admin/presenter.rs
index e8838a3c3..b80cf114f 100644
--- a/backend/crates/gateway-api/src/admin/presenter.rs
+++ b/backend/crates/gateway-api/src/admin/presenter.rs
@@ -3,6 +3,8 @@
 //! 按 docs/project-redundancy-boundary-audit.md BE-02 的目标，display 字段最终
 //! 迁移到前端；过渡期统一由本模块提供，避免 accounts/observability 各自维护。
 
+use gateway_core::accounting::Decimal;
+
 /// 千分位格式化。
 #[must_use]
 pub fn format_number(value: u64) -> String {
@@ -37,3 +39,33 @@ pub fn format_compact_number(value: u64) -> String {
     }
     format_number(value)
 }
+
+/// 货币展示格式化。USD 常规金额保留两位，小于 1 美元时最多保留四位。
+#[must_use]
+pub fn format_decimal_currency(amount: &str, currency: &str) -> String {
+    if currency != "USD" {
+        return format!("{currency} {amount}");
+    }
+
+    const DECIMAL_SCALE: u128 = 10_000_000_000;
+    let scaled = amount.parse::<Decimal>().unwrap_or_default().scaled();
+    let precision = if scaled != 0 && scaled < DECIMAL_SCALE {
+        4_u32
+    } else {
+        2_u32
+    };
+    let rounding_unit = 10_u128.pow(10 - precision);
+    let rounded = (scaled + rounding_unit / 2) / rounding_unit;
+    let display_scale = 10_u128.pow(precision);
+    let whole = rounded / display_scale;
+    let fraction = rounded % display_scale;
+    let mut display = format!("{whole}.{fraction:0width$}", width = precision as usize);
+    while display.ends_with('0')
+        && display
+            .split_once('.')
+            .is_some_and(|(_, fraction)| fraction.len() > 2)
+    {
+        display.pop();
+    }
+    format!("${display}")
+}
diff --git a/backend/crates/gateway-api/tests/admin/accounts.rs b/backend/crates/gateway-api/tests/admin/accounts.rs
index 7a331db5c..79fa600c3 100644
--- a/backend/crates/gateway-api/tests/admin/accounts.rs
+++ b/backend/crates/gateway-api/tests/admin/accounts.rs
@@ -72,6 +72,7 @@ mod query {
 
 mod response {
     use gateway_api::admin::accounts::AccountUsageView;
+    use gateway_api::admin::presenter::format_decimal_currency;
 
     #[test]
     fn account_usage_view_should_keep_unobserved_numbers_null() {
@@ -112,12 +113,21 @@ mod response {
         assert!(value["totalTokens"].is_null());
         assert_eq!(value["createdTokensDisplay"], "-");
     }
+
+    #[test]
+    fn account_usage_currency_should_limit_usd_to_four_fraction_digits() {
+        assert_eq!(format_decimal_currency("0.1204956", "USD"), "$0.1205");
+        assert_eq!(format_decimal_currency("0.99996", "USD"), "$1.00");
+        assert_eq!(format_decimal_currency("0.0300", "USD"), "$0.03");
+        assert_eq!(format_decimal_currency("12.3456", "USD"), "$12.35");
+        assert_eq!(format_decimal_currency("0.1204956", "CNY"), "CNY 0.1204956");
+    }
 }
 
 mod actions {
     use gateway_admin::model::{
         Revision,
-        accounts::{AccountConnectionTestEvent as DomainConnectionTestEvent, AccountStatus},
+        accounts::AccountConnectionTestEvent as DomainConnectionTestEvent,
         provider_credentials::{
             CredentialDeletionResult, CredentialImportResult, CredentialMutationResult,
         },
@@ -343,9 +353,7 @@ mod actions {
             DomainConnectionTestEvent::Content {
                 text: "OK".to_owned(),
             },
-            DomainConnectionTestEvent::Completed {
-                account_status: AccountStatus::Normal,
-            },
+            DomainConnectionTestEvent::Completed {},
             DomainConnectionTestEvent::Failed {
                 message: "upstream unavailable".to_owned(),
                 provider_error_code: Some("usage_exhausted".to_owned()),
@@ -353,7 +361,6 @@ mod actions {
                 upstream_status: Some(429),
                 upstream_content_type: Some("application/json".to_owned()),
                 upstream_body: Some(r#"{"error":{"type":"usage_limit_reached"}}"#.to_owned()),
-                account_status: AccountStatus::QuotaExhausted,
             },
         ]
         .map(|event| AccountConnectionTestEvent::from(event).data);
@@ -378,7 +385,7 @@ mod actions {
                     }
                 }),
                 json!({ "type": "content", "text": "OK" }),
-                json!({ "type": "test_complete", "success": true, "accountStatus": "normal" }),
+                json!({ "type": "test_complete", "success": true }),
                 json!({
                     "type": "error",
                     "error": "upstream unavailable",
@@ -386,8 +393,7 @@ mod actions {
                     "providerErrorType": "invalid_request_error",
                     "upstreamStatus": 429,
                     "upstreamContentType": "application/json",
-                    "upstreamBody": r#"{"error":{"type":"usage_limit_reached"}}"#,
-                    "accountStatus": "quota_exhausted"
+                    "upstreamBody": r#"{"error":{"type":"usage_limit_reached"}}"#
                 }),
             ]
         );
diff --git a/backend/crates/gateway-api/tests/admin/mod.rs b/backend/crates/gateway-api/tests/admin/mod.rs
index eecd47365..08c148842 100644
--- a/backend/crates/gateway-api/tests/admin/mod.rs
+++ b/backend/crates/gateway-api/tests/admin/mod.rs
@@ -14,7 +14,7 @@ use gateway_admin::{
     model::{
         MutationContext, Revision,
         accounts::{
-            AccountListQuery, AccountPage, AccountRecord, AccountUsage, AccountUsageWindowQuery,
+            AccountListQuery, AccountPage, AccountPageItem, AccountUsage, AccountUsageWindowQuery,
             AccountUsageWindowResult, DeleteAccounts, SetAccountEnabled,
         },
         auth::{AdminAuditEvent, AdminSession},
@@ -426,7 +426,7 @@ impl AccountStore for UnusedStore {
         Err(unavailable("account list"))
     }
 
-    async fn load_account(&self, _: &str) -> AdminStoreResult<Option<AccountRecord>> {
+    async fn load_account(&self, _: &str) -> AdminStoreResult<Option<AccountPageItem>> {
         Err(unavailable("account"))
     }
 
diff --git a/backend/crates/gateway-api/tests/admin/observability/response.rs b/backend/crates/gateway-api/tests/admin/observability/response.rs
index 7c1817847..2b2b26c4a 100644
--- a/backend/crates/gateway-api/tests/admin/observability/response.rs
+++ b/backend/crates/gateway-api/tests/admin/observability/response.rs
@@ -222,16 +222,11 @@ async fn dashboard_summary_should_include_quota_exhaustion_in_unavailable_headli
         totals: Default::default(),
         provider_accounts: AccountPoolMetrics {
             total: 807,
-            enabled: 804,
-            unavailable: 792,
-            active: 15,
-            rate_limited: 0,
-            expired: 2,
-            invalid: 0,
+            normal: 15,
             quota_exhausted: 785,
-            refreshing: None,
+            rate_limited: 0,
             disabled: 3,
-            banned: 2,
+            error: 4,
         },
         trend: Vec::new(),
         account_usage: Vec::new(),
diff --git a/backend/crates/gateway-core/src/engine/credential.rs b/backend/crates/gateway-core/src/engine/credential.rs
index 24631e1e8..1c44eac15 100644
--- a/backend/crates/gateway-core/src/engine/credential.rs
+++ b/backend/crates/gateway-core/src/engine/credential.rs
@@ -187,45 +187,41 @@ impl fmt::Debug for OpaqueProviderData {
     }
 }
 
-/// 数据库中固定的账号运行状态。
+/// 已持久化的凭据/账号身份状态。
 ///
-/// 只承载终态或需要外部干预的状态；临时限流（429）不进入此状态，由
-/// Provider quota 数据驱动（`AccountQuotaSignals::limit_reached`）。
+/// 这里只保存凭据与账号身份事实。额度耗尽属于 [`QuotaState`]，临时 429 属于
+/// 运行时冷却；二者都不得写入此枚举。
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum AccountAvailability {
+pub enum CredentialState {
     Unknown,
     Ready,
-    QuotaExhausted,
     Expired,
     Banned,
     Invalid,
 }
 
-impl AccountAvailability {
+impl CredentialState {
     /// 返回数据库稳定值。
     #[must_use]
     pub const fn as_str(self) -> &'static str {
         match self {
             Self::Unknown => "unknown",
             Self::Ready => "ready",
-            Self::QuotaExhausted => "quota_exhausted",
             Self::Expired => "expired",
             Self::Banned => "banned",
             Self::Invalid => "invalid",
         }
     }
 
-    /// 返回账号进入不可恢复错误态、但 Provider 未给出更具体上游原因时的稳定兜底。
-    ///
-    /// Provider 应优先持久化已脱敏的上游 message 或原因码；该值只避免错误态沿用
-    /// 上一次无关的错误信息。
+    /// 返回该凭据状态对应的稳定错误原因。
     #[must_use]
-    pub const fn fallback_error_reason(self) -> Option<&'static str> {
+    pub const fn error_reason(self) -> Option<AccountErrorReason> {
         match self {
-            Self::Expired => Some("credential_expired"),
-            Self::Banned => Some("account_banned"),
-            Self::Invalid => Some("credential_invalid"),
-            Self::Unknown | Self::Ready | Self::QuotaExhausted => None,
+            Self::Unknown => Some(AccountErrorReason::AccountUnverified),
+            Self::Expired => Some(AccountErrorReason::CredentialExpired),
+            Self::Banned => Some(AccountErrorReason::AccountBanned),
+            Self::Invalid => Some(AccountErrorReason::CredentialInvalid),
+            Self::Ready => None,
         }
     }
 
@@ -235,7 +231,6 @@ impl AccountAvailability {
         match value {
             "unknown" => Some(Self::Unknown),
             "ready" => Some(Self::Ready),
-            "quota_exhausted" => Some(Self::QuotaExhausted),
             "expired" => Some(Self::Expired),
             "banned" => Some(Self::Banned),
             "invalid" => Some(Self::Invalid),
@@ -244,6 +239,373 @@ impl AccountAvailability {
     }
 }
 
+/// 额度访问结论；百分比和余额等展示值不进入此枚举。
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum QuotaAccessState {
+    Unknown,
+    Allowed,
+    Exhausted,
+}
+
+impl QuotaAccessState {
+    #[must_use]
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::Unknown => "unknown",
+            Self::Allowed => "allowed",
+            Self::Exhausted => "exhausted",
+        }
+    }
+
+    #[must_use]
+    pub fn parse(value: &str) -> Option<Self> {
+        match value {
+            "unknown" => Some(Self::Unknown),
+            "allowed" => Some(Self::Allowed),
+            "exhausted" => Some(Self::Exhausted),
+            _ => None,
+        }
+    }
+}
+
+/// 权威额度耗尽证据。
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum QuotaEvidence {
+    ProviderDenied,
+    AccountLimitReached,
+    UsageLimitReached,
+    PaymentRequired,
+}
+
+impl QuotaEvidence {
+    #[must_use]
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::ProviderDenied => "provider_denied",
+            Self::AccountLimitReached => "account_limit_reached",
+            Self::UsageLimitReached => "usage_limit_reached",
+            Self::PaymentRequired => "payment_required",
+        }
+    }
+
+    #[must_use]
+    pub fn parse(value: &str) -> Option<Self> {
+        match value {
+            "provider_denied" => Some(Self::ProviderDenied),
+            "account_limit_reached" => Some(Self::AccountLimitReached),
+            "usage_limit_reached" => Some(Self::UsageLimitReached),
+            "payment_required" => Some(Self::PaymentRequired),
+            _ => None,
+        }
+    }
+}
+
+/// 可审计的额度访问事实。
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct QuotaState {
+    access: QuotaAccessState,
+    evidence: Option<QuotaEvidence>,
+    observed_at: Option<SystemTime>,
+    reset_at: Option<SystemTime>,
+}
+
+impl Default for QuotaState {
+    fn default() -> Self {
+        Self::unknown()
+    }
+}
+
+impl QuotaState {
+    #[must_use]
+    pub const fn unknown() -> Self {
+        Self {
+            access: QuotaAccessState::Unknown,
+            evidence: None,
+            observed_at: None,
+            reset_at: None,
+        }
+    }
+
+    #[must_use]
+    pub const fn observed_unknown(observed_at: SystemTime) -> Self {
+        Self {
+            access: QuotaAccessState::Unknown,
+            evidence: None,
+            observed_at: Some(observed_at),
+            reset_at: None,
+        }
+    }
+
+    #[must_use]
+    pub const fn allowed(observed_at: SystemTime) -> Self {
+        Self {
+            access: QuotaAccessState::Allowed,
+            evidence: None,
+            observed_at: Some(observed_at),
+            reset_at: None,
+        }
+    }
+
+    #[must_use]
+    pub const fn exhausted(
+        evidence: QuotaEvidence,
+        observed_at: SystemTime,
+        reset_at: Option<SystemTime>,
+    ) -> Self {
+        Self {
+            access: QuotaAccessState::Exhausted,
+            evidence: Some(evidence),
+            observed_at: Some(observed_at),
+            reset_at,
+        }
+    }
+
+    /// 从持久化列恢复额度状态；非法组合返回 `None`。
+    #[must_use]
+    pub const fn from_persisted(
+        access: QuotaAccessState,
+        evidence: Option<QuotaEvidence>,
+        observed_at: Option<SystemTime>,
+        reset_at: Option<SystemTime>,
+    ) -> Option<Self> {
+        match access {
+            QuotaAccessState::Unknown if evidence.is_none() && reset_at.is_none() => Some(Self {
+                access,
+                evidence,
+                observed_at,
+                reset_at,
+            }),
+            QuotaAccessState::Allowed
+                if evidence.is_none() && observed_at.is_some() && reset_at.is_none() =>
+            {
+                Some(Self {
+                    access,
+                    evidence,
+                    observed_at,
+                    reset_at,
+                })
+            }
+            QuotaAccessState::Exhausted if evidence.is_some() && observed_at.is_some() => {
+                Some(Self {
+                    access,
+                    evidence,
+                    observed_at,
+                    reset_at,
+                })
+            }
+            _ => None,
+        }
+    }
+
+    #[must_use]
+    pub const fn access(self) -> QuotaAccessState {
+        self.access
+    }
+
+    #[must_use]
+    pub const fn evidence(self) -> Option<QuotaEvidence> {
+        self.evidence
+    }
+
+    #[must_use]
+    pub const fn observed_at(self) -> Option<SystemTime> {
+        self.observed_at
+    }
+
+    #[must_use]
+    pub const fn reset_at(self) -> Option<SystemTime> {
+        self.reset_at
+    }
+
+    /// 返回当前已确认的额度耗尽结论。
+    ///
+    /// `reset_at` 只表示何时应重新向 Provider 求证；时间到期本身不是额度恢复证据。
+    #[must_use]
+    pub fn is_exhausted(self) -> bool {
+        self.access == QuotaAccessState::Exhausted
+    }
+
+    /// 判断已耗尽额度是否到达 Provider 的下一次复核时间。
+    ///
+    /// 有明确 `reset_at` 时严格等待该时刻；没有时由 Provider 传入自己的保守复核周期。
+    #[must_use]
+    pub fn exhaustion_refresh_due(self, now: SystemTime, fallback_interval: Duration) -> bool {
+        if !self.is_exhausted() {
+            return false;
+        }
+        let due_at = self.reset_at.or_else(|| {
+            self.observed_at
+                .and_then(|observed_at| observed_at.checked_add(fallback_interval))
+        });
+        due_at.is_none_or(|due_at| due_at <= now)
+    }
+
+    /// 合并一次额度访问观察；`Unknown` 不能擦除已经确认的访问结论。
+    #[must_use]
+    pub fn merge_observation(self, observation: Self) -> Self {
+        if observation.access == QuotaAccessState::Unknown
+            && self.access != QuotaAccessState::Unknown
+        {
+            self
+        } else {
+            observation
+        }
+    }
+}
+
+/// 对外唯一的五态账号状态。
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum AccountStatus {
+    Normal,
+    QuotaExhausted,
+    RateLimited,
+    Disabled,
+    Error,
+}
+
+impl AccountStatus {
+    #[must_use]
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::Normal => "normal",
+            Self::QuotaExhausted => "quota_exhausted",
+            Self::RateLimited => "rate_limited",
+            Self::Disabled => "disabled",
+            Self::Error => "error",
+        }
+    }
+
+    #[must_use]
+    pub fn parse(value: &str) -> Option<Self> {
+        match value {
+            "normal" => Some(Self::Normal),
+            "quota_exhausted" => Some(Self::QuotaExhausted),
+            "rate_limited" => Some(Self::RateLimited),
+            "disabled" => Some(Self::Disabled),
+            "error" => Some(Self::Error),
+            _ => None,
+        }
+    }
+
+    /// 管理页稳定业务排序：正常、限流、耗尽、错误、停用。
+    #[must_use]
+    pub const fn sort_rank(self) -> u8 {
+        match self {
+            Self::Normal => 0,
+            Self::RateLimited => 1,
+            Self::QuotaExhausted => 2,
+            Self::Error => 3,
+            Self::Disabled => 4,
+        }
+    }
+}
+
+/// `error` 状态下的稳定原因码。
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum AccountErrorReason {
+    AccountUnverified,
+    AccessTokenExpired,
+    CredentialExpired,
+    CredentialInvalid,
+    AccountBanned,
+}
+
+impl AccountErrorReason {
+    #[must_use]
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::AccountUnverified => "account_unverified",
+            Self::AccessTokenExpired => "access_token_expired",
+            Self::CredentialExpired => "credential_expired",
+            Self::CredentialInvalid => "credential_invalid",
+            Self::AccountBanned => "account_banned",
+        }
+    }
+
+    #[must_use]
+    pub fn parse(value: &str) -> Option<Self> {
+        match value {
+            "account_unverified" => Some(Self::AccountUnverified),
+            "access_token_expired" => Some(Self::AccessTokenExpired),
+            "credential_expired" => Some(Self::CredentialExpired),
+            "credential_invalid" => Some(Self::CredentialInvalid),
+            "account_banned" => Some(Self::AccountBanned),
+            _ => None,
+        }
+    }
+}
+
+/// 唯一状态解析器的完整输入事实。
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AccountStatusFacts {
+    pub enabled: bool,
+    pub credential_state: CredentialState,
+    pub access_token_expires_at: Option<SystemTime>,
+    pub quota: QuotaState,
+    pub rate_limited_until: Option<SystemTime>,
+    pub last_error_reason: Option<AccountErrorReason>,
+    pub last_error_message: Option<String>,
+}
+
+/// 唯一状态解析器的输出。
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AccountStatusProjection {
+    pub status: AccountStatus,
+    pub error_reason: Option<AccountErrorReason>,
+    pub error_message: Option<String>,
+    /// 仅 `rate_limited` 状态携带仍有效的运行时冷却截止时间。
+    pub rate_limited_until: Option<SystemTime>,
+}
+
+/// 从独立事实派生唯一、互斥的对外状态。
+#[must_use]
+pub fn resolve_account_status(
+    facts: &AccountStatusFacts,
+    now: SystemTime,
+) -> AccountStatusProjection {
+    if !facts.enabled {
+        return status_projection(AccountStatus::Disabled);
+    }
+    let credential_error = facts.credential_state.error_reason().or_else(|| {
+        facts
+            .access_token_expires_at
+            .is_some_and(|expires_at| expires_at <= now)
+            .then_some(AccountErrorReason::AccessTokenExpired)
+    });
+    if let Some(default_reason) = credential_error {
+        return AccountStatusProjection {
+            status: AccountStatus::Error,
+            error_reason: Some(facts.last_error_reason.unwrap_or(default_reason)),
+            error_message: facts.last_error_message.clone(),
+            rate_limited_until: None,
+        };
+    }
+    if facts.quota.is_exhausted() {
+        return status_projection(AccountStatus::QuotaExhausted);
+    }
+    if facts
+        .rate_limited_until
+        .is_some_and(|rate_limited_until| rate_limited_until > now)
+    {
+        return AccountStatusProjection {
+            status: AccountStatus::RateLimited,
+            error_reason: None,
+            error_message: None,
+            rate_limited_until: facts.rate_limited_until,
+        };
+    }
+    status_projection(AccountStatus::Normal)
+}
+
+const fn status_projection(status: AccountStatus) -> AccountStatusProjection {
+    AccountStatusProjection {
+        status,
+        error_reason: None,
+        error_message: None,
+        rate_limited_until: None,
+    }
+}
+
 /// 不含 secret 的账号持久事实。
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ProviderAccount {
@@ -257,7 +619,10 @@ pub struct ProviderAccount {
     authentication_kind: String,
     revision: CredentialRevision,
     enabled: bool,
-    availability: AccountAvailability,
+    credential_state: CredentialState,
+    quota: QuotaState,
+    last_error_reason: Option<AccountErrorReason>,
+    last_error_message: Option<String>,
     access_token_expires_at: Option<SystemTime>,
     next_refresh_at: Option<SystemTime>,
     has_refresh_token: bool,
@@ -286,7 +651,10 @@ impl ProviderAccount {
             authentication_kind,
             revision,
             enabled: true,
-            availability: AccountAvailability::Unknown,
+            credential_state: CredentialState::Unknown,
+            quota: QuotaState::unknown(),
+            last_error_reason: None,
+            last_error_message: None,
             access_token_expires_at,
             next_refresh_at: None,
             has_refresh_token: false,
@@ -307,17 +675,23 @@ impl ProviderAccount {
     }
 
     #[must_use]
-    pub const fn with_runtime_state(
+    pub fn with_account_facts(
         mut self,
         enabled: bool,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
+        quota: QuotaState,
+        last_error_reason: Option<AccountErrorReason>,
+        last_error_message: Option<String>,
     ) -> Self {
         self.enabled = enabled;
-        self.availability = if self.upstream_user_id.is_some() {
-            availability
+        self.credential_state = if self.upstream_user_id.is_some() {
+            credential_state
         } else {
-            AccountAvailability::Unknown
+            CredentialState::Unknown
         };
+        self.quota = quota;
+        self.last_error_reason = last_error_reason;
+        self.last_error_message = last_error_message;
         self
     }
 
@@ -382,8 +756,23 @@ impl ProviderAccount {
     }
 
     #[must_use]
-    pub const fn availability(&self) -> AccountAvailability {
-        self.availability
+    pub const fn credential_state(&self) -> CredentialState {
+        self.credential_state
+    }
+
+    #[must_use]
+    pub const fn quota(&self) -> QuotaState {
+        self.quota
+    }
+
+    #[must_use]
+    pub const fn last_error_reason(&self) -> Option<AccountErrorReason> {
+        self.last_error_reason
+    }
+
+    #[must_use]
+    pub fn last_error_message(&self) -> Option<&str> {
+        self.last_error_message.as_deref()
     }
 
     #[must_use]
@@ -407,23 +796,25 @@ impl ProviderAccount {
         self.has_refresh_token
     }
 
-    /// 判断账号当前能否进入同 target 的候选池。
+    /// 组合持久事实与请求级冷却，交给唯一解析器派生状态。
     #[must_use]
-    pub fn is_schedulable(&self, now: SystemTime) -> bool {
-        let available = match self.availability {
-            AccountAvailability::Ready => true,
-            AccountAvailability::Unknown
-            | AccountAvailability::QuotaExhausted
-            | AccountAvailability::Expired
-            | AccountAvailability::Banned
-            | AccountAvailability::Invalid => false,
-        };
-        self.upstream_user_id.is_some()
-            && self.enabled
-            && available
-            && self
-                .access_token_expires_at
-                .is_none_or(|expires_at| expires_at > now)
+    pub fn status_projection(
+        &self,
+        now: SystemTime,
+        rate_limited_until: Option<SystemTime>,
+    ) -> AccountStatusProjection {
+        resolve_account_status(
+            &AccountStatusFacts {
+                enabled: self.enabled,
+                credential_state: self.credential_state,
+                access_token_expires_at: self.access_token_expires_at,
+                quota: self.quota,
+                rate_limited_until,
+                last_error_reason: self.last_error_reason,
+                last_error_message: self.last_error_message.clone(),
+            },
+            now,
+        )
     }
 }
 
@@ -600,10 +991,11 @@ pub enum CredentialCasOutcome {
 pub struct QuotaObservation {
     pub account_id: ProviderAccountId,
     pub expected_revision: CredentialRevision,
-    pub quota: Option<OpaqueProviderData>,
-    pub observed_at: Option<SystemTime>,
-    /// 快照级限流事实（Provider 解析后物化）；None 表示不更新物化列。
-    pub limit_reached: Option<bool>,
+    pub quota: OpaqueProviderData,
+    /// Provider 原始 quota document 的观察时间；不代表访问结论发生变化。
+    pub observed_at: SystemTime,
+    /// Provider 已从私有 JSON 归一化出的额度访问事实。
+    pub state: QuotaState,
 }
 
 impl fmt::Debug for QuotaObservation {
@@ -614,6 +1006,7 @@ impl fmt::Debug for QuotaObservation {
             .field("expected_revision", &self.expected_revision)
             .field("quota", &self.quota)
             .field("observed_at", &self.observed_at)
+            .field("state", &self.state)
             .finish()
     }
 }
@@ -624,14 +1017,24 @@ pub enum QuotaWriteOutcome {
     Conflict,
 }
 
+/// 不改 Provider 原始 quota JSON 的额度访问事实写入。
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct QuotaAccessChange {
+    pub account_id: ProviderAccountId,
+    pub expected_revision: CredentialRevision,
+    pub state: QuotaState,
+}
+
 /// 账号状态的 revision-fenced 写入。
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct AccountStateChange {
     pub account_id: ProviderAccountId,
     pub expected_revision: CredentialRevision,
-    pub availability: AccountAvailability,
+    pub credential_state: CredentialState,
     pub observed_at: SystemTime,
-    /// 上游原因（错误原文 / 原因码）；`Some` 写入持久化错误信息，`None` 不更新，恢复 `Ready` 时清空。
+    /// 受控错误原因；恢复 Ready 时必须清空。
+    pub error_reason: Option<AccountErrorReason>,
+    /// 已脱敏的上游诊断信息；恢复 Ready 时必须清空。
     pub message: Option<String>,
 }
 
@@ -682,6 +1085,11 @@ pub trait ProviderAccountStore: Send + Sync {
         observation: QuotaObservation,
     ) -> Result<QuotaWriteOutcome, StoreError>;
 
+    async fn apply_quota_access(
+        &self,
+        change: QuotaAccessChange,
+    ) -> Result<QuotaWriteOutcome, StoreError>;
+
     async fn apply_state_change(&self, change: AccountStateChange) -> Result<(), StoreError>;
 
     async fn update_account(&self, update: ProviderAccountUpdate) -> Result<(), StoreError>;
@@ -772,7 +1180,7 @@ pub struct AccountRuntimeSignals {
     pub last_started_at: Option<SystemTime>,
     pub quota_reset_at: Option<SystemTime>,
     pub quota_remaining_rank: Option<u64>,
-    pub quota_limit_reached: bool,
+    pub rate_limited_until: Option<SystemTime>,
     pub failure_rate_basis_points: Option<u16>,
     pub first_output_latency_ms: Option<u64>,
 }
@@ -920,11 +1328,16 @@ impl AccountRuntimeSignals {
         if let Some(quota) = quota {
             self.quota_reset_at = quota.reset_at;
             self.quota_remaining_rank = quota.remaining_rank;
-            self.quota_limit_reached = quota.limit_reached;
         }
         self
     }
 
+    #[must_use]
+    pub const fn with_rate_limit(mut self, rate_limited_until: Option<SystemTime>) -> Self {
+        self.rate_limited_until = rate_limited_until;
+        self
+    }
+
     #[must_use]
     pub const fn with_runtime_health(
         mut self,
@@ -942,20 +1355,14 @@ impl AccountRuntimeSignals {
 pub struct AccountQuotaSignals {
     reset_at: Option<SystemTime>,
     remaining_rank: Option<u64>,
-    limit_reached: bool,
 }
 
 impl AccountQuotaSignals {
     #[must_use]
-    pub const fn new(
-        reset_at: Option<SystemTime>,
-        remaining_rank: Option<u64>,
-        limit_reached: bool,
-    ) -> Self {
+    pub const fn new(reset_at: Option<SystemTime>, remaining_rank: Option<u64>) -> Self {
         Self {
             reset_at,
             remaining_rank,
-            limit_reached,
         }
     }
 
@@ -968,12 +1375,6 @@ impl AccountQuotaSignals {
     pub const fn remaining_rank(self) -> Option<u64> {
         self.remaining_rank
     }
-
-    /// 任一计量窗口已触顶（`limit_reached`/`used_percent >= 100`）；调度据此排除候选。
-    #[must_use]
-    pub const fn limit_reached(self) -> bool {
-        self.limit_reached
-    }
 }
 
 /// 账号持久事实与可重建运行信号的请求级组合。
@@ -991,24 +1392,24 @@ pub struct AccountSelectionContext {
     pub excluded_accounts: BTreeSet<ProviderAccountId>,
     pub preferred_account: Option<ProviderAccountId>,
     pub round_robin_cursor: u64,
-    pub availability: AccountAvailabilityPolicy,
+    pub eligibility: AccountEligibilityPolicy,
 }
 
-/// 选择账号时是否信任本地可用性投影。
+/// 选择账号时是否执行本地调度资格投影。
 ///
 /// 管理端对指定账号执行诊断时，会直接向上游确认实际状态；该模式跳过
 /// `enabled`、可用性、冷却和 token 到期等本地投影，仍保留租约、并发和
 /// 请求间隔约束，且只能与固定账号约束组合使用。
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
-pub enum AccountAvailabilityPolicy {
+pub enum AccountEligibilityPolicy {
     #[default]
     Enforce,
     BypassForDiagnostic,
 }
 
-impl AccountAvailabilityPolicy {
+impl AccountEligibilityPolicy {
     #[must_use]
-    pub const fn bypasses_local_availability(self) -> bool {
+    pub const fn bypasses_local_eligibility(self) -> bool {
         matches!(self, Self::BypassForDiagnostic)
     }
 }
@@ -1132,10 +1533,14 @@ impl AccountSelector {
         candidate: &AccountCandidate,
         context: &AccountSelectionContext,
     ) -> Option<AccountSchedulingBlocker> {
-        if !context.availability.bypasses_local_availability()
-            && !candidate.account.is_schedulable(context.now)
-        {
-            return Some(AccountSchedulingBlocker::LocalAvailability);
+        if !context.eligibility.bypasses_local_eligibility() {
+            let status = candidate
+                .account
+                .status_projection(context.now, candidate.signals.rate_limited_until)
+                .status;
+            if status != AccountStatus::Normal {
+                return Some(AccountSchedulingBlocker::LocalAvailability);
+            }
         }
         if context.excluded_accounts.contains(candidate.account.id()) {
             return Some(AccountSchedulingBlocker::Excluded);
diff --git a/backend/crates/gateway-core/src/provider_ports/mod.rs b/backend/crates/gateway-core/src/provider_ports/mod.rs
index 689db3f6a..2bd85a32f 100644
--- a/backend/crates/gateway-core/src/provider_ports/mod.rs
+++ b/backend/crates/gateway-core/src/provider_ports/mod.rs
@@ -9,7 +9,7 @@ use std::time::{Duration, SystemTime};
 use futures::future::BoxFuture;
 
 use crate::engine::credential::{
-    AccountAvailability, AccountFeedbackStats, AccountRuntimeSignals, CredentialRevision,
+    AccountFeedbackStats, AccountRuntimeSignals, CredentialRevision, CredentialState,
     OpaqueProviderData, ProviderAccountId, ProviderAccountStore,
 };
 use crate::error::{IdentifierError, validate_text};
@@ -411,7 +411,7 @@ pub struct ProviderCredentialState {
     account_id: ProviderAccountId,
     credential_revision: CredentialRevision,
     enabled: bool,
-    availability: AccountAvailability,
+    credential_state: CredentialState,
     observed_at: SystemTime,
 }
 
@@ -421,14 +421,14 @@ impl ProviderCredentialState {
         account_id: ProviderAccountId,
         credential_revision: CredentialRevision,
         enabled: bool,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
         observed_at: SystemTime,
     ) -> Self {
         Self {
             account_id,
             credential_revision,
             enabled,
-            availability,
+            credential_state,
             observed_at,
         }
     }
@@ -449,8 +449,8 @@ impl ProviderCredentialState {
     }
 
     #[must_use]
-    pub const fn availability(&self) -> AccountAvailability {
-        self.availability
+    pub const fn credential_state(&self) -> CredentialState {
+        self.credential_state
     }
 
     #[must_use]
diff --git a/backend/crates/gateway-core/tests/engine/credential.rs b/backend/crates/gateway-core/tests/engine/credential.rs
index 2590657cf..3afbedac7 100644
--- a/backend/crates/gateway-core/tests/engine/credential.rs
+++ b/backend/crates/gateway-core/tests/engine/credential.rs
@@ -5,12 +5,12 @@ use std::time::{Duration, SystemTime};
 use serde_json::{Map, Value};
 
 use gateway_core::engine::credential::{
-    AccountAttemptFeedback, AccountAvailability, AccountAvailabilityPolicy, AccountCandidate,
-    AccountFeedbackStats, AccountQuotaSignals, AccountRuntimeSignals, AccountSchedulingBlocker,
-    AccountSelectionContext, AccountSelectionPolicy, AccountSelector, CredentialCasUpdate,
-    CredentialRevision, OpaqueProviderData, PlaintextCredential, PreferredAccountSelection,
-    ProviderAccount, ProviderAccountId, ProviderAccountIdentity, ProviderAccountUpdate,
-    RotationStrategy,
+    AccountAttemptFeedback, AccountCandidate, AccountEligibilityPolicy, AccountFeedbackStats,
+    AccountQuotaSignals, AccountRuntimeSignals, AccountSchedulingBlocker, AccountSelectionContext,
+    AccountSelectionPolicy, AccountSelector, AccountStatus, CredentialCasUpdate,
+    CredentialRevision, CredentialState, OpaqueProviderData, PlaintextCredential,
+    PreferredAccountSelection, ProviderAccount, ProviderAccountId, ProviderAccountIdentity,
+    ProviderAccountUpdate, QuotaEvidence, QuotaState, RotationStrategy,
 };
 use gateway_core::routing::ProviderKind;
 
@@ -24,7 +24,13 @@ fn account(id: &str) -> ProviderAccount {
         CredentialRevision::new(1).expect("valid revision"),
         Some(SystemTime::now() + Duration::from_secs(3600)),
     )
-    .with_runtime_state(true, AccountAvailability::Ready)
+    .with_account_facts(
+        true,
+        CredentialState::Ready,
+        QuotaState::unknown(),
+        None,
+        None,
+    )
 }
 
 fn candidate(id: &str, in_flight: u32, remaining: Option<u64>) -> AccountCandidate {
@@ -35,7 +41,7 @@ fn candidate(id: &str, in_flight: u32, remaining: Option<u64>) -> AccountCandida
             last_started_at: None,
             quota_reset_at: None,
             quota_remaining_rank: remaining,
-            quota_limit_reached: false,
+            rate_limited_until: None,
             failure_rate_basis_points: None,
             first_output_latency_ms: None,
         },
@@ -53,7 +59,7 @@ fn context(strategy: RotationStrategy) -> AccountSelectionContext {
         excluded_accounts: BTreeSet::new(),
         preferred_account: None,
         round_robin_cursor: 0,
-        availability: AccountAvailabilityPolicy::Enforce,
+        eligibility: AccountEligibilityPolicy::Enforce,
     }
 }
 
@@ -101,43 +107,99 @@ fn provider_account_identity_debug_should_redact_upstream_ids() {
 }
 
 #[test]
-fn availability_should_round_trip_all_database_values() {
+fn account_fact_values_should_round_trip() {
     assert_eq!(
-        AccountAvailability::parse(AccountAvailability::QuotaExhausted.as_str()),
-        Some(AccountAvailability::QuotaExhausted)
+        CredentialState::parse(CredentialState::Banned.as_str()),
+        Some(CredentialState::Banned)
+    );
+    assert_eq!(
+        QuotaEvidence::parse("provider_denied"),
+        Some(QuotaEvidence::ProviderDenied)
     );
 }
 
 #[test]
-fn diagnostic_selection_bypasses_all_local_account_availability() {
+fn exhausted_quota_refresh_is_due_at_reset_or_provider_fallback() {
+    let now = SystemTime::now();
+    let observed_at = now - Duration::from_secs(60);
+    let before_reset = QuotaState::exhausted(
+        QuotaEvidence::ProviderDenied,
+        observed_at,
+        Some(now + Duration::from_secs(1)),
+    );
+    let after_reset = QuotaState::exhausted(
+        QuotaEvidence::ProviderDenied,
+        observed_at,
+        Some(now - Duration::from_secs(1)),
+    );
+    let without_reset = QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None);
+
+    assert!(!before_reset.exhaustion_refresh_due(now, Duration::from_secs(30)));
+    assert!(after_reset.exhaustion_refresh_due(now, Duration::from_secs(30)));
+    assert!(without_reset.exhaustion_refresh_due(now, Duration::from_secs(30)));
+    assert!(!without_reset.exhaustion_refresh_due(now, Duration::from_secs(120)));
+}
+
+#[test]
+fn inconclusive_quota_observation_cannot_erase_confirmed_access() {
+    let now = SystemTime::now();
+    let exhausted = QuotaState::exhausted(QuotaEvidence::ProviderDenied, now, None);
+
+    assert_eq!(
+        exhausted
+            .merge_observation(QuotaState::observed_unknown(now + Duration::from_secs(1)))
+            .access(),
+        gateway_core::engine::credential::QuotaAccessState::Exhausted
+    );
+    assert_eq!(
+        exhausted
+            .merge_observation(QuotaState::allowed(now + Duration::from_secs(1)))
+            .access(),
+        gateway_core::engine::credential::QuotaAccessState::Allowed
+    );
+}
+
+#[test]
+fn diagnostic_selection_bypasses_all_local_account_eligibility() {
+    let observed_at = SystemTime::now();
     let exhausted = AccountCandidate {
-        account: account("acct_exhausted")
-            .with_runtime_state(true, AccountAvailability::QuotaExhausted),
+        account: account("acct_exhausted").with_account_facts(
+            true,
+            CredentialState::Ready,
+            QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
+            None,
+            None,
+        ),
         signals: AccountRuntimeSignals {
             in_flight: 0,
             last_started_at: None,
             quota_reset_at: None,
             quota_remaining_rank: None,
-            quota_limit_reached: false,
+            rate_limited_until: None,
             failure_rate_basis_points: None,
             first_output_latency_ms: None,
         },
     };
     let disabled = AccountCandidate {
-        account: account("acct_disabled")
-            .with_runtime_state(false, AccountAvailability::QuotaExhausted),
+        account: account("acct_disabled").with_account_facts(
+            false,
+            CredentialState::Ready,
+            QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
+            None,
+            None,
+        ),
         signals: AccountRuntimeSignals {
             in_flight: 0,
             last_started_at: None,
             quota_reset_at: None,
             quota_remaining_rank: None,
-            quota_limit_reached: false,
+            rate_limited_until: None,
             failure_rate_basis_points: None,
             first_output_latency_ms: None,
         },
     };
     let mut context = context(RotationStrategy::Sticky);
-    context.availability = AccountAvailabilityPolicy::BypassForDiagnostic;
+    context.eligibility = AccountEligibilityPolicy::BypassForDiagnostic;
 
     assert_eq!(
         AccountSelector
@@ -155,9 +217,33 @@ fn diagnostic_selection_bypasses_all_local_account_availability() {
 
 #[test]
 fn disabled_account_should_not_be_schedulable() {
-    let account = account("acct_disabled").with_runtime_state(false, AccountAvailability::Ready);
+    let account = account("acct_disabled").with_account_facts(
+        false,
+        CredentialState::Ready,
+        QuotaState::unknown(),
+        None,
+        None,
+    );
 
-    assert!(!account.is_schedulable(SystemTime::now()));
+    assert_eq!(
+        account.status_projection(SystemTime::now(), None).status,
+        AccountStatus::Disabled
+    );
+}
+
+#[test]
+fn rate_limited_projection_carries_only_the_active_cooldown_deadline() {
+    let now = SystemTime::now();
+    let active_until = now + Duration::from_secs(60);
+    let account = account("acct_rate_limited");
+
+    let active = account.status_projection(now, Some(active_until));
+    assert_eq!(active.status, AccountStatus::RateLimited);
+    assert_eq!(active.rate_limited_until, Some(active_until));
+
+    let elapsed = account.status_projection(now, Some(now - Duration::from_secs(1)));
+    assert_eq!(elapsed.status, AccountStatus::Normal);
+    assert_eq!(elapsed.rate_limited_until, None);
 }
 
 #[test]
@@ -171,14 +257,20 @@ fn account_without_upstream_identity_should_stay_unknown_and_not_schedulable() {
         CredentialRevision::new(1).expect("valid revision"),
         Some(SystemTime::now() + Duration::from_secs(3600)),
     )
-    .with_runtime_state(true, AccountAvailability::Ready);
+    .with_account_facts(
+        true,
+        CredentialState::Ready,
+        QuotaState::unknown(),
+        None,
+        None,
+    );
 
     assert_eq!(
         (
-            account.availability(),
-            account.is_schedulable(SystemTime::now())
+            account.credential_state(),
+            account.status_projection(SystemTime::now(), None).status
         ),
-        (AccountAvailability::Unknown, false)
+        (CredentialState::Unknown, AccountStatus::Error)
     );
 }
 
@@ -308,15 +400,11 @@ fn provider_quota_overlay_should_preserve_store_concurrency_facts() {
         last_started_at: Some(last_started_at),
         quota_reset_at: None,
         quota_remaining_rank: None,
-        quota_limit_reached: false,
+        rate_limited_until: None,
         failure_rate_basis_points: None,
         first_output_latency_ms: None,
     }
-    .with_provider_quota(Some(AccountQuotaSignals::new(
-        Some(reset_at),
-        Some(75),
-        false,
-    )));
+    .with_provider_quota(Some(AccountQuotaSignals::new(Some(reset_at), Some(75))));
 
     assert_eq!(
         (
@@ -633,21 +721,31 @@ fn credential_cas_should_reject_refresh_schedule_without_refresh_token() {
 }
 
 #[test]
-fn enforced_availability_excludes_terminal_states_despite_quota_signals() {
-    // availability 终态（Banned/Expired/Invalid）始终排除，
-    // 不受 quota 信号或 skip_exhausted 放宽影响。
+fn enforced_eligibility_excludes_credential_errors_despite_quota_signals() {
     let mut banned = candidate("acct_banned", 0, Some(100));
-    banned.account = banned
-        .account
-        .with_runtime_state(true, AccountAvailability::Banned);
+    banned.account = banned.account.with_account_facts(
+        true,
+        CredentialState::Banned,
+        QuotaState::unknown(),
+        None,
+        None,
+    );
     let mut expired = candidate("acct_expired", 0, Some(100));
-    expired.account = expired
-        .account
-        .with_runtime_state(true, AccountAvailability::Expired);
+    expired.account = expired.account.with_account_facts(
+        true,
+        CredentialState::Expired,
+        QuotaState::unknown(),
+        None,
+        None,
+    );
     let mut invalid = candidate("acct_invalid", 0, Some(100));
-    invalid.account = invalid
-        .account
-        .with_runtime_state(true, AccountAvailability::Invalid);
+    invalid.account = invalid.account.with_account_facts(
+        true,
+        CredentialState::Invalid,
+        QuotaState::unknown(),
+        None,
+        None,
+    );
     let healthy = candidate("acct_healthy", 0, Some(100));
     let candidates = vec![banned, expired, invalid, healthy];
 
@@ -659,14 +757,15 @@ fn enforced_availability_excludes_terminal_states_despite_quota_signals() {
 }
 
 #[test]
-fn enforced_availability_allows_quota_exhausted_with_skip_exhausted_projection() {
-    // QuotaExhausted 是可恢复额度耗尽，skip_exhausted=false 的
-    // 放宽投影（provider 层）允许其参与调度；core 的 Enforce 策略本身
-    // 只排除终态。这里验证 Enforce 下 QuotaExhausted 仍被排除（严格模式）。
+fn enforced_eligibility_excludes_authoritative_quota_exhaustion() {
     let mut exhausted = candidate("acct_exhausted", 0, Some(100));
-    exhausted.account = exhausted
-        .account
-        .with_runtime_state(true, AccountAvailability::QuotaExhausted);
+    exhausted.account = exhausted.account.with_account_facts(
+        true,
+        CredentialState::Ready,
+        QuotaState::exhausted(QuotaEvidence::ProviderDenied, SystemTime::now(), None),
+        None,
+        None,
+    );
     let healthy = candidate("acct_healthy", 0, Some(100));
     let candidates = vec![exhausted, healthy];
 
@@ -676,3 +775,31 @@ fn enforced_availability_allows_quota_exhausted_with_skip_exhausted_projection()
 
     assert_eq!(selected.candidate().account.id().as_str(), "acct_healthy");
 }
+
+#[test]
+fn elapsed_quota_reset_does_not_fabricate_recovery() {
+    let now = SystemTime::now();
+    let mut exhausted = candidate("acct_exhausted", 0, Some(100));
+    exhausted.account = exhausted.account.with_account_facts(
+        true,
+        CredentialState::Ready,
+        QuotaState::exhausted(
+            QuotaEvidence::ProviderDenied,
+            now - Duration::from_secs(2),
+            Some(now - Duration::from_secs(1)),
+        ),
+        None,
+        None,
+    );
+    let healthy = candidate("acct_healthy", 0, Some(100));
+
+    assert_eq!(
+        exhausted.account.status_projection(now, None).status,
+        AccountStatus::QuotaExhausted
+    );
+    let candidates = [exhausted, healthy];
+    let selected = AccountSelector
+        .select(&candidates, &context(RotationStrategy::Smart))
+        .expect("healthy candidate available");
+    assert_eq!(selected.candidate().account.id().as_str(), "acct_healthy");
+}
diff --git a/backend/crates/gateway-core/tests/provider_ports/mod.rs b/backend/crates/gateway-core/tests/provider_ports/mod.rs
index 2f538d8d7..18de8934d 100644
--- a/backend/crates/gateway-core/tests/provider_ports/mod.rs
+++ b/backend/crates/gateway-core/tests/provider_ports/mod.rs
@@ -92,7 +92,7 @@ fn scheduling_state_preserves_provider_neutral_signals() {
             last_started_at: None,
             quota_reset_at: None,
             quota_remaining_rank: Some(7),
-            quota_limit_reached: false,
+            rate_limited_until: None,
             failure_rate_basis_points: Some(125),
             first_output_latency_ms: Some(250),
         },
diff --git a/backend/crates/gateway-store/src/postgres/observability/admin_adapter.rs b/backend/crates/gateway-store/src/postgres/observability/admin_adapter.rs
index ceaa9d706..98b438f66 100644
--- a/backend/crates/gateway-store/src/postgres/observability/admin_adapter.rs
+++ b/backend/crates/gateway-store/src/postgres/observability/admin_adapter.rs
@@ -1,12 +1,15 @@
 //! Pg 观测 adapter：实现 `ObservabilityRepository` 与 `AdminObservabilityStore`。
 
-use std::sync::Arc;
-use std::time::SystemTime;
-
 use gateway_core::provider_ports::ProviderCooldownPort;
+use std::sync::Arc;
 
 use super::*;
 
+use crate::postgres::{
+    PgProviderAccountRepository, ProviderAccountRepository, account_status_projection,
+    load_rate_limited_until,
+};
+
 use crate::redis::{CredentialLeaseRepository as _, RedisCredentialLeaseRepository};
 
 #[derive(Clone)]
@@ -21,73 +24,48 @@ impl PgObservabilityRepository {
         Self { pool, cooldowns }
     }
 
-    /// 账号池指标：SQL 聚合后，仅用 Redis 429 冷却重分类仍可调度的 ready 账号。
-    /// 冷却中从 `active` 或 `quota_exhausted` 移到 `rate_limited`；冷却不可用时保留 SQL 分类。
-    async fn provider_account_metrics_with_cooldowns(
+    /// 从账号事实和当前冷却一次性派生 Dashboard 五态；不在 SQL 中复制状态机。
+    async fn account_status_snapshot(
         &self,
         observed_at: DateTime<Utc>,
-    ) -> StoreResult<ProviderAccountMetrics> {
-        let base = provider_account_metrics(&self.pool, observed_at).await?;
-        let Some(cooldowns) = &self.cooldowns else {
-            return Ok(base);
+    ) -> StoreResult<(ProviderAccountMetrics, Vec<String>)> {
+        let accounts = PgProviderAccountRepository::new(self.pool.clone())
+            .list_provider_accounts(None, true)
+            .await?;
+        let now = observed_at.into();
+        let rate_limited_until =
+            load_rate_limited_until(self.cooldowns.as_deref(), &accounts, now).await;
+        let mut metrics = ProviderAccountMetrics {
+            total: u64::try_from(accounts.len()).unwrap_or(u64::MAX),
+            ..ProviderAccountMetrics::default()
         };
-        let candidates = schedulable_metric_candidates(&self.pool, observed_at).await?;
-        if candidates.is_empty() {
-            return Ok(base);
-        }
-        // Redis 只能把 SQL 已归入 active/quota_exhausted 的候选移到冷却桶；
-        // 其余状态不重建，避免 Redis 失败或脏 ID 时丢失持久化计数。
-        let mut active = base.active;
-        let mut rate_limited = base.rate_limited;
-        let mut quota_exhausted = base.quota_exhausted;
-        let now = SystemTime::now();
-        for (account_id, revision, quota_reached) in candidates {
-            let Ok(account_id) =
-                gateway_core::engine::credential::ProviderAccountId::new(account_id)
-            else {
-                continue;
-            };
-            let cooling = cooldowns
-                .read(&account_id)
-                .await
-                .ok()
-                .flatten()
-                .filter(|cooldown| cooldown.credential_revision().get() as i64 == revision)
-                .filter(|cooldown| cooldown.until() > now)
-                .is_some();
-            if !cooling {
-                continue;
-            }
-            if quota_reached {
-                if quota_exhausted == 0 {
-                    continue;
+        let mut normal_account_ids = Vec::new();
+        for account in &accounts {
+            let projection = account_status_projection(
+                account,
+                now,
+                rate_limited_until.get(&account.id).copied(),
+            );
+            match projection.status {
+                gateway_core::engine::credential::AccountStatus::Normal => {
+                    metrics.normal = metrics.normal.saturating_add(1);
+                    normal_account_ids.push(account.id.clone());
                 }
-                quota_exhausted -= 1;
-            } else {
-                if active == 0 {
-                    continue;
+                gateway_core::engine::credential::AccountStatus::QuotaExhausted => {
+                    metrics.quota_exhausted = metrics.quota_exhausted.saturating_add(1);
+                }
+                gateway_core::engine::credential::AccountStatus::RateLimited => {
+                    metrics.rate_limited = metrics.rate_limited.saturating_add(1);
+                }
+                gateway_core::engine::credential::AccountStatus::Disabled => {
+                    metrics.disabled = metrics.disabled.saturating_add(1);
+                }
+                gateway_core::engine::credential::AccountStatus::Error => {
+                    metrics.error = metrics.error.saturating_add(1);
                 }
-                active -= 1;
             }
-            rate_limited += 1;
         }
-        Ok(ProviderAccountMetrics {
-            total: base.total,
-            enabled: base.enabled,
-            unavailable: rate_limited
-                + quota_exhausted
-                + base.expired
-                + base.invalid
-                + base.disabled
-                + base.banned,
-            active,
-            rate_limited,
-            expired: base.expired,
-            invalid: base.invalid,
-            quota_exhausted,
-            disabled: base.disabled,
-            banned: base.banned,
-        })
+        Ok((metrics, normal_account_ids))
     }
 }
 
@@ -145,9 +123,7 @@ impl ObservabilityRepository for PgObservabilityRepository {
             attempt_metrics(&self.pool, range, &filter),
             dashboard_totals(&self.pool),
         )?;
-        let provider_accounts = self
-            .provider_account_metrics_with_cooldowns(range.end)
-            .await?;
+        let (provider_accounts, _) = self.account_status_snapshot(range.end).await?;
         let (trend, account_usage, recent_requests) = futures::try_join!(
             request_metric_series(&self.pool, range, &filter),
             provider_account_usage(&self.pool, account_usage_query),
@@ -252,12 +228,14 @@ impl AdminObservabilityStore for PgAdminObservabilityStore {
         &self,
         observed_at: DateTime<Utc>,
     ) -> AdminStoreResult<Option<admin_observability::DashboardRuntimeSlots>> {
-        let active_account_ids = active_provider_account_ids(&self.repository.pool, observed_at)
+        let (_, normal_account_ids) = self
+            .repository
+            .account_status_snapshot(observed_at)
             .await
             .map_err(observability_error)?;
-        let active_accounts = u64::try_from(active_account_ids.len())
+        let active_accounts = u64::try_from(normal_account_ids.len())
             .map_err(|_| observability_error(invalid("active account count overflows u64")))?;
-        if active_account_ids.is_empty() {
+        if normal_account_ids.is_empty() {
             return Ok(Some(admin_observability::DashboardRuntimeSlots {
                 active_accounts,
                 used_slots: Some(0),
@@ -267,7 +245,7 @@ impl AdminObservabilityStore for PgAdminObservabilityStore {
             return Ok(None);
         };
         let signals = match runtime_signals
-            .credential_runtime_signals(&active_account_ids)
+            .credential_runtime_signals(&normal_account_ids)
             .await
         {
             Ok(signals) => signals,
diff --git a/backend/crates/gateway-store/src/postgres/observability/mapping.rs b/backend/crates/gateway-store/src/postgres/observability/mapping.rs
index eb8925dca..4e692d371 100644
--- a/backend/crates/gateway-store/src/postgres/observability/mapping.rs
+++ b/backend/crates/gateway-store/src/postgres/observability/mapping.rs
@@ -274,16 +274,11 @@ pub(crate) const fn admin_account_pool_metrics(
 ) -> admin_observability::AccountPoolMetrics {
     admin_observability::AccountPoolMetrics {
         total: metrics.total,
-        enabled: metrics.enabled,
-        unavailable: metrics.unavailable,
-        active: metrics.active,
-        rate_limited: metrics.rate_limited,
-        expired: metrics.expired,
-        invalid: metrics.invalid,
+        normal: metrics.normal,
         quota_exhausted: metrics.quota_exhausted,
-        refreshing: None,
+        rate_limited: metrics.rate_limited,
         disabled: metrics.disabled,
-        banned: metrics.banned,
+        error: metrics.error,
     }
 }
 
@@ -297,8 +292,6 @@ pub(crate) fn admin_dashboard_account_usage(
         name: usage.name,
         email: usage.email,
         plan_type: usage.plan_type,
-        enabled: usage.enabled,
-        availability: usage.availability,
         request_count: usage.request_count,
         success_count: usage.success_count,
         input_tokens: usage.input_tokens,
diff --git a/backend/crates/gateway-store/src/postgres/observability/model.rs b/backend/crates/gateway-store/src/postgres/observability/model.rs
index 260f391b8..33d8083d3 100644
--- a/backend/crates/gateway-store/src/postgres/observability/model.rs
+++ b/backend/crates/gateway-store/src/postgres/observability/model.rs
@@ -363,15 +363,11 @@ pub struct CalculatedUsageBillingFact {
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 pub struct ProviderAccountMetrics {
     pub total: u64,
-    pub enabled: u64,
-    pub unavailable: u64,
-    pub active: u64,
-    pub rate_limited: u64,
-    pub expired: u64,
-    pub invalid: u64,
+    pub normal: u64,
     pub quota_exhausted: u64,
+    pub rate_limited: u64,
     pub disabled: u64,
-    pub banned: u64,
+    pub error: u64,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -388,8 +384,6 @@ pub struct ProviderAccountUsageObservation {
     pub name: String,
     pub email: Option<String>,
     pub plan_type: Option<String>,
-    pub enabled: bool,
-    pub availability: String,
     pub request_count: u64,
     pub success_count: u64,
     pub input_tokens: Option<u64>,
diff --git a/backend/crates/gateway-store/src/postgres/observability/queries/accounts.rs b/backend/crates/gateway-store/src/postgres/observability/queries/accounts.rs
index 43036f8e8..b354a7d39 100644
--- a/backend/crates/gateway-store/src/postgres/observability/queries/accounts.rs
+++ b/backend/crates/gateway-store/src/postgres/observability/queries/accounts.rs
@@ -15,7 +15,7 @@ pub(crate) async fn provider_account_usage(
 
     let mut statement = QueryBuilder::<Postgres>::new(
         "select pa.id, pa.provider_kind, pa.authentication_kind, pa.name, pa.email,
-                pa.plan_type, pa.enabled, pa.availability,
+                pa.plan_type,
                 count(mr.id)::bigint as request_count,
                 count(mr.id) filter (where mr.outcome = 'succeeded')::bigint as success_count,
                 sum(mr.input_tokens)::bigint as input_tokens,
@@ -52,7 +52,7 @@ pub(crate) async fn provider_account_usage(
     }
     statement.push(
         " group by pa.id, pa.provider_kind, pa.authentication_kind, pa.name, pa.email,
-                   pa.plan_type, pa.enabled, pa.availability
+                   pa.plan_type
           order by max(mr.started_at) desc nulls last, pa.name, pa.id limit ",
     );
     statement.push_bind(i64::from(query.limit));
@@ -313,8 +313,6 @@ pub(crate) fn provider_account_from_row(
         name: get(row, "name")?,
         email: get(row, "email")?,
         plan_type: get(row, "plan_type")?,
-        enabled: get(row, "enabled")?,
-        availability: get(row, "availability")?,
         request_count: unsigned(row, "request_count")?,
         success_count: unsigned(row, "success_count")?,
         input_tokens: optional_unsigned(row, "input_tokens")?,
diff --git a/backend/crates/gateway-store/src/postgres/observability/queries/dashboard.rs b/backend/crates/gateway-store/src/postgres/observability/queries/dashboard.rs
index 8edf883ca..a5de6fd28 100644
--- a/backend/crates/gateway-store/src/postgres/observability/queries/dashboard.rs
+++ b/backend/crates/gateway-store/src/postgres/observability/queries/dashboard.rs
@@ -369,118 +369,6 @@ pub(crate) async fn request_costs(
         .collect()
 }
 
-pub(crate) async fn provider_account_metrics(
-    pool: &PgPool,
-    observed_at: DateTime<Utc>,
-) -> StoreResult<ProviderAccountMetrics> {
-    let row = sqlx::query(
-        "with normalized as (
-           select enabled, availability, quota_limit_reached,
-                  case
-                    when not enabled then 'disabled'
-                    when availability = 'banned' then 'banned'
-                    when availability = 'quota_exhausted' then 'quota_exhausted'
-                    when availability = 'invalid' then 'invalid'
-                    when availability = 'expired'
-                      or (access_token_expires_at is not null and access_token_expires_at <= $1)
-                      then 'expired'
-                    when availability = 'unknown' then 'invalid'
-                    when quota_limit_reached then 'quota_exhausted'
-                    else 'active'
-                  end as status
-             from provider_accounts
-         )
-         select count(*)::bigint as total,
-                count(*) filter (where enabled)::bigint as enabled,
-                count(*) filter (where status in ('rate_limited','quota_exhausted','expired','invalid','disabled','banned'))::bigint as unavailable,
-                count(*) filter (where status = 'active')::bigint as active,
-                count(*) filter (where status = 'rate_limited')::bigint as rate_limited,
-                count(*) filter (where status = 'expired')::bigint as expired,
-                count(*) filter (where status = 'invalid')::bigint as invalid,
-                count(*) filter (where status = 'quota_exhausted')::bigint as quota_exhausted,
-                count(*) filter (where status = 'disabled')::bigint as disabled,
-                count(*) filter (where status = 'banned')::bigint as banned
-           from normalized",
-    )
-    .bind(observed_at)
-    .fetch_one(pool)
-    .await
-    .map_err(|_| postgres_unavailable("load provider account metrics"))?;
-    Ok(ProviderAccountMetrics {
-        total: unsigned(&row, "total")?,
-        enabled: unsigned(&row, "enabled")?,
-        unavailable: unsigned(&row, "unavailable")?,
-        active: unsigned(&row, "active")?,
-        rate_limited: unsigned(&row, "rate_limited")?,
-        expired: unsigned(&row, "expired")?,
-        invalid: unsigned(&row, "invalid")?,
-        quota_exhausted: unsigned(&row, "quota_exhausted")?,
-        disabled: unsigned(&row, "disabled")?,
-        banned: unsigned(&row, "banned")?,
-    })
-}
-
-pub(crate) async fn active_provider_account_ids(
-    pool: &PgPool,
-    observed_at: DateTime<Utc>,
-) -> StoreResult<Vec<String>> {
-    sqlx::query(
-        "with normalized as (
-           select id,
-                  case
-                    when not enabled then 'disabled'
-                    when availability = 'banned' then 'banned'
-                    when availability = 'quota_exhausted' then 'quota_exhausted'
-                    when availability in ('expired', 'invalid')
-                      or (access_token_expires_at is not null and access_token_expires_at <= $1)
-                      then 'expired'
-                    else 'active'
-                  end as status
-             from provider_accounts
-         )
-         select id
-           from normalized
-          where status = 'active'
-          order by id",
-    )
-    .bind(observed_at)
-    .fetch_all(pool)
-    .await
-    .map_err(|_| postgres_unavailable("load active provider account IDs"))?
-    .iter()
-    .map(|row| get(row, "id"))
-    .collect()
-}
-
-/// 查询可被 Redis 冷却重新归类的 ready 账号：id、credential revision 与 quota 标记。
-/// 已过期或非 ready 的账号由 [`provider_account_metrics`] 直接计数。
-pub(crate) async fn schedulable_metric_candidates(
-    pool: &PgPool,
-    observed_at: DateTime<Utc>,
-) -> StoreResult<Vec<(String, i64, bool)>> {
-    sqlx::query(
-        "select id, credential_revision, quota_limit_reached
-           from provider_accounts
-          where enabled
-            and availability = 'ready'
-            and (access_token_expires_at is null or access_token_expires_at > $1)
-          order by id",
-    )
-    .bind(observed_at)
-    .fetch_all(pool)
-    .await
-    .map_err(|_| postgres_unavailable("load schedulable metric candidates"))?
-    .into_iter()
-    .map(|row| {
-        Ok((
-            get(&row, "id")?,
-            get(&row, "credential_revision")?,
-            get(&row, "quota_limit_reached")?,
-        ))
-    })
-    .collect::<StoreResult<Vec<_>>>()
-}
-
 pub(crate) async fn provider_observations(
     pool: &PgPool,
     range: ObservabilityRange,
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/admin_adapter.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/admin_adapter.rs
index e92752fc2..cdf042650 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/admin_adapter.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/admin_adapter.rs
@@ -2,7 +2,6 @@
 
 use std::collections::BTreeMap;
 use std::sync::Arc;
-use std::time::SystemTime;
 
 use gateway_core::provider_ports::ProviderCooldownPort;
 
@@ -32,34 +31,6 @@ impl PgAdminAccountStore {
         }
     }
 
-    /// 批量读取 Redis 429 冷却，返回 `account_id → rate_limited_until` 映射。
-    /// 冷却不可用（Redis 挂/无 cooldown 端口）时返回空映射，账号归入配额耗尽（近似）。
-    async fn load_rate_limited_until(
-        &self,
-        accounts: &[ProviderAccountSummary],
-    ) -> AdminStoreResult<BTreeMap<String, SystemTime>> {
-        let Some(cooldowns) = &self.cooldowns else {
-            return Ok(BTreeMap::new());
-        };
-        let mut map = BTreeMap::new();
-        for account in accounts {
-            let Ok(account_id) = CoreProviderAccountId::new(account.id.clone()) else {
-                continue;
-            };
-            let Some(cooldown) = cooldowns.read(&account_id).await.ok().flatten() else {
-                continue;
-            };
-            if cooldown.credential_revision().get() != account.credential_revision.get() {
-                continue;
-            }
-            let until = cooldown.until();
-            if until > SystemTime::now() {
-                map.insert(account.id.clone(), until);
-            }
-        }
-        Ok(map)
-    }
-
     async fn usage_observations(
         &self,
         range: ObservabilityRange,
@@ -278,21 +249,18 @@ impl AccountStore for PgAdminAccountStore {
         )
         .map_err(|error| admin_store_error(ENTITY, error))?;
         let now = Utc::now();
-        // 批量读取 Redis 429 冷却，供列表状态派生与筛选使用。
-        let rate_limited_until = self
-            .load_rate_limited_until(&accounts)
-            .await
-            .unwrap_or_default();
+        let rate_limited_until =
+            load_rate_limited_until(self.cooldowns.as_deref(), &accounts, now.into()).await;
         let summary = admin_account_summary(&accounts, now, &rate_limited_until);
         let mut items = accounts
             .into_iter()
             .filter_map(|account| {
                 let until = rate_limited_until.get(&account.id).copied();
-                let status = admin_account_status(&account, now, until);
-                account_matches_admin_query(&account, status, &query).then_some(
+                let projection = account_status_projection(&account, now.into(), until);
+                account_matches_admin_query(&account, projection.status, &query).then_some(
                     AdminAccountListItem {
                         account,
-                        status,
+                        projection,
                         usage: None,
                     },
                 )
@@ -330,7 +298,12 @@ impl AccountStore for PgAdminAccountStore {
             .into_iter()
             .skip(offset)
             .take(page_size)
-            .map(|item| admin_account_record(item.account))
+            .map(|item| {
+                Ok(AccountPageItem {
+                    account: admin_account_record(item.account)?,
+                    projection: item.projection,
+                })
+            })
             .collect::<AdminStoreResult<Vec<_>>>()?;
         Ok(AccountPage {
             config_revision: admin_revision(control_plane.settings.config_revision)?,
@@ -340,13 +313,29 @@ impl AccountStore for PgAdminAccountStore {
         })
     }
 
-    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountRecord>> {
-        self.accounts
+    async fn load_account(&self, account_id: &str) -> AdminStoreResult<Option<AccountPageItem>> {
+        let record = self
+            .accounts
             .load_provider_account(account_id)
             .await
-            .map_err(|error| admin_store_error(ENTITY, error))?
-            .map(|record| admin_account_record(record.summary))
-            .transpose()
+            .map_err(|error| admin_store_error(ENTITY, error))?;
+        let Some(record) = record else {
+            return Ok(None);
+        };
+        let now = Utc::now();
+        let rate_limited_until = load_rate_limited_until(
+            self.cooldowns.as_deref(),
+            std::slice::from_ref(&record.summary),
+            now.into(),
+        )
+        .await
+        .get(account_id)
+        .copied();
+        let projection = account_status_projection(&record.summary, now.into(), rate_limited_until);
+        Ok(Some(AccountPageItem {
+            account: admin_account_record(record.summary)?,
+            projection,
+        }))
     }
 
     async fn load_account_usage(
@@ -386,9 +375,9 @@ impl AccountStore for PgAdminAccountStore {
             .filter(|account| account.provider_kind == provider_kind.as_str())
             .filter(|account| {
                 query
-                    .availability
+                    .credential_state
                     .as_ref()
-                    .is_none_or(|expected| expected.matches(account.availability))
+                    .is_none_or(|expected| expected.matches(account.credential_state))
             })
             .filter(|account| {
                 query
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/core_adapter.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/core_adapter.rs
index 62f853bb9..a4a09f1a2 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/core_adapter.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/core_adapter.rs
@@ -31,8 +31,8 @@ impl ProviderAccountStore for PgProviderAccountRepository {
                 .map(DateTime::<Utc>::from),
             next_refresh_at: account.account.next_refresh_at().map(DateTime::<Utc>::from),
             enabled: account.account.enabled(),
-            availability: account.account.availability(),
-            availability_observed_at: Utc::now(),
+            credential_state: account.account.credential_state(),
+            credential_observed_at: Utc::now(),
         })
         .await
         .map_err(core_store_error)
@@ -164,9 +164,9 @@ impl ProviderAccountStore for PgProviderAccountRepository {
             .collect::<Vec<_>>();
         let rows = sqlx::query(
             "select id, credential_revision, provider_quota_json, quota_observed_at, \
-                    quota_limit_reached \
+                    quota_access_state, quota_evidence, quota_access_observed_at, quota_reset_at \
              from provider_accounts \
-             where id = any($1) and provider_quota_json is not null",
+             where id = any($1) and quota_observed_at is not null",
         )
         .bind(account_ids)
         .fetch_all(&self.pool)
@@ -184,24 +184,49 @@ impl ProviderAccountStore for PgProviderAccountRepository {
                     .and_then(|value| CoreCredentialRevision::new(value).ok())
                     .ok_or_else(|| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
                 let quota = row
-                    .try_get::<serde_json::Value, _>("provider_quota_json")
-                    .ok()
+                    .try_get::<Option<serde_json::Value>, _>("provider_quota_json")
+                    .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?
                     .and_then(|value| value.as_object().cloned())
                     .map(OpaqueProviderData::new)
-                    .ok_or_else(|| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
+                    .unwrap_or_else(|| OpaqueProviderData::new(serde_json::Map::new()));
                 let observed_at = row
                     .try_get::<DateTime<Utc>, _>("quota_observed_at")
                     .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
-                let limit_reached = row
-                    .try_get::<bool, _>("quota_limit_reached")
+                let access = row
+                    .try_get::<String, _>("quota_access_state")
+                    .ok()
+                    .and_then(|value| QuotaAccessState::parse(&value))
+                    .ok_or_else(|| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
+                let evidence = row
+                    .try_get::<Option<String>, _>("quota_evidence")
                     .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
+                let evidence = match evidence {
+                    Some(value) => Some(
+                        QuotaEvidence::parse(&value)
+                            .ok_or_else(|| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?,
+                    ),
+                    None => None,
+                };
+                let reset_at = row
+                    .try_get::<Option<DateTime<Utc>>, _>("quota_reset_at")
+                    .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
+                let access_observed_at = row
+                    .try_get::<Option<DateTime<Utc>>, _>("quota_access_observed_at")
+                    .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
+                let state = QuotaState::from_persisted(
+                    access,
+                    evidence,
+                    access_observed_at.map(Into::into),
+                    reset_at.map(Into::into),
+                )
+                .ok_or_else(|| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?;
                 Ok(QuotaObservation {
                     account_id: CoreProviderAccountId::new(account_id)
                         .map_err(|_| CoreStoreError::new(CoreStoreErrorKind::InvalidData))?,
                     expected_revision: revision,
-                    quota: Some(quota),
-                    observed_at: Some(observed_at.into()),
-                    limit_reached: Some(limit_reached),
+                    quota,
+                    observed_at: observed_at.into(),
+                    state,
                 })
             })
             .collect()
@@ -211,24 +236,38 @@ impl ProviderAccountStore for PgProviderAccountRepository {
         &self,
         observation: QuotaObservation,
     ) -> Result<QuotaWriteOutcome, CoreStoreError> {
-        let quota = observation
-            .quota
-            .map(|value| {
-                JsonObject::try_from_value(
-                    "provider_quota_json",
-                    serde_json::Value::Object(value.into_inner()),
-                    QUOTA_MAX_BYTES,
-                )
-            })
-            .transpose()
-            .map_err(core_store_error)?;
+        let quota = JsonObject::try_from_value(
+            "provider_quota_json",
+            serde_json::Value::Object(observation.quota.into_inner()),
+            QUOTA_MAX_BYTES,
+        )
+        .map_err(core_store_error)?;
         let updated = self
             .compare_and_swap_provider_quota(
                 observation.account_id.as_str(),
                 Revision::new(observation.expected_revision.get()).map_err(core_store_error)?,
                 quota,
-                observation.observed_at.map(DateTime::<Utc>::from),
-                observation.limit_reached,
+                DateTime::<Utc>::from(observation.observed_at),
+                observation.state,
+            )
+            .await
+            .map_err(core_store_error)?;
+        Ok(if updated {
+            QuotaWriteOutcome::Updated
+        } else {
+            QuotaWriteOutcome::Conflict
+        })
+    }
+
+    async fn apply_quota_access(
+        &self,
+        change: QuotaAccessChange,
+    ) -> Result<QuotaWriteOutcome, CoreStoreError> {
+        let updated = self
+            .apply_provider_quota_access(
+                change.account_id.as_str(),
+                Revision::new(change.expected_revision.get()).map_err(core_store_error)?,
+                change.state,
             )
             .await
             .map_err(core_store_error)?;
@@ -245,8 +284,9 @@ impl ProviderAccountStore for PgProviderAccountRepository {
                 account_id: change.account_id.as_str().to_owned(),
                 expected_revision: Revision::new(change.expected_revision.get())
                     .map_err(core_store_error)?,
-                availability: change.availability,
-                availability_observed_at: DateTime::<Utc>::from(change.observed_at),
+                credential_state: change.credential_state,
+                credential_observed_at: DateTime::<Utc>::from(change.observed_at),
+                error_reason: change.error_reason,
                 message: change.message,
             })
             .await
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/mapping.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/mapping.rs
index 49d9bcdf9..882c2adef 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/mapping.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/mapping.rs
@@ -1,12 +1,12 @@
 //! Admin 账号列表、用量与成本的领域映射。
 
+use std::time::SystemTime;
+
 use super::*;
 
-use gateway_admin::model::accounts::AccountStatusSignals;
-
 pub(crate) struct AdminAccountListItem {
     pub(crate) account: ProviderAccountSummary,
-    pub(crate) status: AdminAccountStatus,
+    pub(crate) projection: gateway_core::engine::credential::AccountStatusProjection,
     pub(crate) usage: Option<ProviderAccountUsageObservation>,
 }
 
@@ -57,24 +57,6 @@ pub(crate) fn account_matches_admin_query(
     provider_matches && search_matches && status_matches
 }
 
-pub(crate) fn admin_account_status(
-    account: &ProviderAccountSummary,
-    now: DateTime<Utc>,
-    rate_limited_until: Option<SystemTime>,
-) -> AdminAccountStatus {
-    // 派生规则唯一归属 gateway-admin 域层，此处只做类型适配。
-    AccountStatusSignals {
-        enabled: account.enabled,
-        availability: account.availability,
-        access_token_expired: account
-            .access_token_expires_at
-            .is_some_and(|expires_at| expires_at <= now),
-        quota_limit_reached: account.quota_limit_reached,
-        rate_limited_until,
-    }
-    .derive()
-}
-
 pub(crate) fn admin_account_summary(
     accounts: &[ProviderAccountSummary],
     now: DateTime<Utc>,
@@ -90,7 +72,7 @@ pub(crate) fn admin_account_summary(
     };
     for account in accounts {
         let until = rate_limited_until.get(&account.id).copied();
-        match admin_account_status(account, now, until) {
+        match account_status_projection(account, now.into(), until).status {
             AdminAccountStatus::Normal => summary.normal = summary.normal.saturating_add(1),
             AdminAccountStatus::QuotaExhausted => {
                 summary.quota_exhausted = summary.quota_exhausted.saturating_add(1);
@@ -118,7 +100,11 @@ pub(crate) fn sort_admin_account_items(
     items.sort_by(|left, right| {
         let ordering = match sort.field {
             AdminAccountSortField::Email => left.account.email.cmp(&right.account.email),
-            AdminAccountSortField::Status => left.status.as_str().cmp(right.status.as_str()),
+            AdminAccountSortField::Status => left
+                .projection
+                .status
+                .sort_rank()
+                .cmp(&right.projection.status.sort_rank()),
             AdminAccountSortField::PlanType => left.account.plan_type.cmp(&right.account.plan_type),
             AdminAccountSortField::Usage => left
                 .usage
@@ -171,10 +157,11 @@ pub(crate) fn admin_account_record(
         access_token_expires_at: summary.access_token_expires_at,
         next_refresh_at: summary.next_refresh_at,
         enabled: summary.enabled,
-        availability: summary.availability,
-        availability_observed_at: summary.availability_observed_at,
+        credential_state: summary.credential_state,
+        credential_observed_at: summary.credential_observed_at,
+        quota: summary.quota,
+        last_error_reason: summary.last_error_reason,
         last_error_message: summary.last_error_message,
-        quota_observed_at: summary.quota_observed_at,
         created_at: summary.created_at,
         updated_at: summary.updated_at,
     })
@@ -197,8 +184,8 @@ pub(crate) fn prepared_account(
         access_token_expires_at: credential.access_token_expires_at,
         next_refresh_at: credential.next_refresh_at,
         enabled: credential.enabled,
-        availability: credential.availability,
-        availability_observed_at: credential.availability_observed_at,
+        credential_state: credential.credential_state,
+        credential_observed_at: credential.credential_observed_at,
     })
 }
 
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/mod.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/mod.rs
index b4b32b579..a2f89ebd3 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/mod.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/mod.rs
@@ -4,7 +4,6 @@ use std::{
     collections::{BTreeMap, BTreeSet},
     fmt,
     str::FromStr,
-    time::SystemTime,
 };
 
 use async_trait::async_trait;
@@ -14,7 +13,7 @@ use gateway_admin::{
         MutationContext, Revision as AdminRevision,
         accounts::{
             AccountCost, AccountListQuery as AdminAccountListQuery, AccountModelUsage, AccountPage,
-            AccountRecord, AccountRequestBucket, AccountSort as AdminAccountSort,
+            AccountPageItem, AccountRecord, AccountRequestBucket, AccountSort as AdminAccountSort,
             AccountSortField as AdminAccountSortField, AccountStatus as AdminAccountStatus,
             AccountSummary, AccountUsage, AccountUsageWindowQuery, AccountUsageWindowResult,
             DeleteAccounts, SetAccountEnabled, SortDirection as AdminSortDirection,
@@ -35,12 +34,13 @@ use gateway_admin::{
 use sqlx::{PgPool, Postgres, Row, Transaction};
 
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
-    CredentialRevision as CoreCredentialRevision, LoadedCredential,
+    AccountErrorReason, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
+    CredentialRevision as CoreCredentialRevision, CredentialState, LoadedCredential,
     NewProviderAccount as CoreNewProviderAccount, OpaqueProviderData, PlaintextCredential,
     ProviderAccount as CoreProviderAccount, ProviderAccountId as CoreProviderAccountId,
     ProviderAccountIdentity, ProviderAccountStore,
-    ProviderAccountUpdate as CoreProviderAccountUpdate, QuotaObservation, QuotaWriteOutcome,
+    ProviderAccountUpdate as CoreProviderAccountUpdate, QuotaAccessChange, QuotaAccessState,
+    QuotaEvidence, QuotaObservation, QuotaState, QuotaWriteOutcome,
 };
 use gateway_core::error::{StoreError as CoreStoreError, StoreErrorKind as CoreStoreErrorKind};
 use gateway_core::routing::ProviderKind;
@@ -63,8 +63,10 @@ mod core_adapter;
 mod mapping;
 mod repository;
 mod rows;
+mod runtime;
 
 pub use admin_adapter::*;
 pub(crate) use mapping::*;
 pub use repository::*;
 pub use rows::*;
+pub(crate) use runtime::*;
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/repository.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/repository.rs
index 0a9eafbb9..f08137e1f 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/repository.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/repository.rs
@@ -25,9 +25,15 @@ pub trait ProviderAccountRepository: Send + Sync {
         &self,
         account_id: &str,
         expected_revision: Revision,
-        quota: Option<JsonObject>,
-        observed_at: Option<DateTime<Utc>>,
-        limit_reached: Option<bool>,
+        quota: JsonObject,
+        observed_at: DateTime<Utc>,
+        state: QuotaState,
+    ) -> StoreResult<bool>;
+    async fn apply_provider_quota_access(
+        &self,
+        account_id: &str,
+        expected_revision: Revision,
+        state: QuotaState,
     ) -> StoreResult<bool>;
     async fn delete_provider_account(&self, id: &str) -> StoreResult<bool>;
 }
@@ -93,9 +99,10 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
         let rows = sqlx::query(
             "select id, provider_kind, name, email, upstream_user_id,
                     upstream_account_id, plan_type, authentication_kind, credential_revision, has_refresh_token,
-                    access_token_expires_at, next_refresh_at, enabled, availability,
-                    availability_observed_at,
-                    quota_observed_at, quota_limit_reached, last_error_message, created_at, updated_at
+                    access_token_expires_at, next_refresh_at, enabled, credential_state,
+                    credential_observed_at, quota_access_state, quota_evidence,
+                    quota_access_observed_at, quota_reset_at,
+                    quota_observed_at, last_error_reason, last_error_message, created_at, updated_at
              from provider_accounts
              where ($1::text is null or provider_kind = $1) and ($2 or enabled)
              order by provider_kind, name, id",
@@ -110,21 +117,21 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
 
     async fn insert_provider_account(&self, account: NewProviderAccount) -> StoreResult<()> {
         account.validate()?;
-        let availability = if account.upstream_user_id.is_some() {
-            account.availability
+        let credential_state = if account.upstream_user_id.is_some() {
+            account.credential_state
         } else {
-            AccountAvailability::Unknown
+            CredentialState::Unknown
         };
         sqlx::query(
             "insert into provider_accounts (
                id, provider_kind, name, email, upstream_user_id,
                upstream_account_id, plan_type, authentication_kind, provider_credentials_json, credential_revision,
                has_refresh_token, access_token_expires_at, next_refresh_at, enabled,
-               availability, provider_quota_json,
-               availability_observed_at, quota_observed_at, created_at, updated_at
+               credential_state, provider_quota_json,
+               credential_observed_at, quota_access_observed_at, quota_observed_at, created_at, updated_at
              ) values (
                $1, $2, $3, $4, $5, $6, $7, $8, $9, 1, $10, $11, $12, $13,
-               $14, null, $15, null, now(), greatest(now(), $15)
+               $14, null, $15, null, null, now(), greatest(now(), $15)
              )",
         )
         .bind(account.id)
@@ -140,8 +147,8 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
         .bind(account.access_token_expires_at)
         .bind(account.next_refresh_at)
         .bind(account.enabled)
-        .bind(availability.as_str())
-        .bind(account.availability_observed_at)
+        .bind(credential_state.as_str())
+        .bind(account.credential_observed_at)
         .execute(&self.pool)
         .await
         .map_err(|_| postgres_unavailable("insert provider account"))?;
@@ -214,27 +221,33 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
         update.validate()?;
         let result = sqlx::query(
             "update provider_accounts
-             set availability = case
+             set credential_state = case
                      when enabled and upstream_user_id is not null then $3
-                     else availability
+                     else credential_state
                  end,
-                 availability_observed_at = case
+                 credential_observed_at = case
                      when enabled and upstream_user_id is not null then $4
-                     else availability_observed_at
+                     else credential_observed_at
+                 end,
+                 last_error_reason = case
+                     when enabled and upstream_user_id is not null then
+                         case when $3 = 'ready' then null else $5 end
+                     else last_error_reason
                  end,
                  last_error_message = case
                      when enabled and upstream_user_id is not null then
-                         case when $3 = 'ready' then null else coalesce($5, last_error_message) end
+                         case when $3 = 'ready' then null else $6 end
                      else last_error_message
                  end,
                  updated_at = case when enabled then greatest(now(), $4) else updated_at end
              where id = $1 and credential_revision = $2
-               and (availability_observed_at is null or availability_observed_at <= $4)",
+               and (credential_observed_at is null or credential_observed_at <= $4)",
         )
         .bind(update.account_id)
         .bind(to_i64(update.expected_revision.get())?)
-        .bind(update.availability.as_str())
-        .bind(update.availability_observed_at)
+        .bind(update.credential_state.as_str())
+        .bind(update.credential_observed_at)
+        .bind(update.error_reason.map(AccountErrorReason::as_str))
         .bind(update.message.as_deref())
         .execute(&self.pool)
         .await
@@ -259,36 +272,81 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
         &self,
         account_id: &str,
         expected_revision: Revision,
-        quota: Option<JsonObject>,
-        observed_at: Option<DateTime<Utc>>,
-        limit_reached: Option<bool>,
+        quota: JsonObject,
+        observed_at: DateTime<Utc>,
+        state: QuotaState,
     ) -> StoreResult<bool> {
         require_nonempty(ENTITY, "account_id", account_id)?;
-        if quota.is_some() != observed_at.is_some() {
-            return Err(invalid("quota JSON and observed_at must agree"));
-        }
-        if let Some(quota) = quota.as_ref() {
-            validate_object_size("provider_quota_json", quota, QUOTA_MAX_BYTES)?;
-        }
+        validate_object_size("provider_quota_json", &quota, QUOTA_MAX_BYTES)?;
+        let access_observed_at = state.observed_at().map(DateTime::<Utc>::from);
         let result = sqlx::query(
             "update provider_accounts
              set provider_quota_json = $3, quota_observed_at = $4,
-                 quota_limit_reached = coalesce($5, quota_limit_reached),
-                 updated_at = greatest(now(), coalesce($4, now()))
+                 quota_access_state = case
+                   when $7::timestamptz is not null
+                     and (quota_access_observed_at is null or quota_access_observed_at <= $7)
+                   then $5 else quota_access_state end,
+                 quota_evidence = case
+                   when $7::timestamptz is not null
+                     and (quota_access_observed_at is null or quota_access_observed_at <= $7)
+                   then $6 else quota_evidence end,
+                 quota_access_observed_at = case
+                   when $7::timestamptz is not null
+                     and (quota_access_observed_at is null or quota_access_observed_at <= $7)
+                   then $7 else quota_access_observed_at end,
+                 quota_reset_at = case
+                   when $7::timestamptz is not null
+                     and (quota_access_observed_at is null or quota_access_observed_at <= $7)
+                   then $8 else quota_reset_at end,
+                 updated_at = greatest(now(), $4)
              where id = $1 and credential_revision = $2
-               and ($4 is null or quota_observed_at is null or quota_observed_at <= $4)",
+               and (quota_observed_at is null or quota_observed_at <= $4)",
         )
         .bind(account_id)
         .bind(to_i64(expected_revision.get())?)
-        .bind(quota.map(|value| value.as_value()))
+        .bind(quota.as_value())
         .bind(observed_at)
-        .bind(limit_reached)
+        .bind(state.access().as_str())
+        .bind(state.evidence().map(QuotaEvidence::as_str))
+        .bind(access_observed_at)
+        .bind(state.reset_at().map(DateTime::<Utc>::from))
         .execute(&self.pool)
         .await
         .map_err(|_| postgres_unavailable("compare and swap provider quota"))?;
         Ok(result.rows_affected() == 1)
     }
 
+    async fn apply_provider_quota_access(
+        &self,
+        account_id: &str,
+        expected_revision: Revision,
+        state: QuotaState,
+    ) -> StoreResult<bool> {
+        require_nonempty(ENTITY, "account_id", account_id)?;
+        let observed_at = state
+            .observed_at()
+            .map(DateTime::<Utc>::from)
+            .ok_or_else(|| invalid("quota access change requires observed_at"))?;
+        let result = sqlx::query(
+            "update provider_accounts
+             set quota_access_observed_at = $3, quota_access_state = $4,
+                 quota_evidence = $5, quota_reset_at = $6,
+                 updated_at = greatest(now(), $3)
+             where id = $1 and credential_revision = $2
+               and (quota_access_observed_at is null or quota_access_observed_at <= $3)",
+        )
+        .bind(account_id)
+        .bind(to_i64(expected_revision.get())?)
+        .bind(observed_at)
+        .bind(state.access().as_str())
+        .bind(state.evidence().map(QuotaEvidence::as_str))
+        .bind(state.reset_at().map(DateTime::<Utc>::from))
+        .execute(&self.pool)
+        .await
+        .map_err(|_| postgres_unavailable("apply provider quota access"))?;
+        Ok(result.rows_affected() == 1)
+    }
+
     async fn delete_provider_account(&self, id: &str) -> StoreResult<bool> {
         require_nonempty(ENTITY, "id", id)?;
         let result = sqlx::query("delete from provider_accounts where id = $1 and not enabled")
@@ -474,21 +532,21 @@ pub(crate) async fn upsert_provider_account_in_transaction(
     account: &NewProviderAccount,
 ) -> StoreResult<String> {
     account.validate()?;
-    let availability = if account.upstream_user_id.is_some() {
-        account.availability
+    let credential_state = if account.upstream_user_id.is_some() {
+        account.credential_state
     } else {
-        AccountAvailability::Unknown
+        CredentialState::Unknown
     };
     let imported_id = sqlx::query_scalar::<_, String>(
         "insert into provider_accounts (
            id, provider_kind, name, email, upstream_user_id,
            upstream_account_id, plan_type, authentication_kind, provider_credentials_json, credential_revision,
            has_refresh_token, access_token_expires_at, next_refresh_at, enabled,
-           availability, provider_quota_json,
-           availability_observed_at, quota_observed_at, created_at, updated_at
+           credential_state, provider_quota_json,
+           credential_observed_at, quota_access_observed_at, quota_observed_at, created_at, updated_at
          ) values (
            $1, $2, $3, $4, $5, $6, $7, $8, $9, 1, $10, $11, $12, $13,
-           $14, null, $15, null, now(), greatest(now(), $15)
+           $14, null, $15, null, null, now(), greatest(now(), $15)
          )
          on conflict (
            provider_kind,
@@ -505,11 +563,17 @@ pub(crate) async fn upsert_provider_account_in_transaction(
            access_token_expires_at = excluded.access_token_expires_at,
            next_refresh_at = excluded.next_refresh_at,
            enabled = excluded.enabled,
-           availability = excluded.availability,
+           credential_state = excluded.credential_state,
            provider_quota_json = null,
-           availability_observed_at = excluded.availability_observed_at,
+           quota_access_state = 'unknown',
+           quota_evidence = null,
+           quota_access_observed_at = null,
+           quota_reset_at = null,
+           credential_observed_at = excluded.credential_observed_at,
            quota_observed_at = null,
-           updated_at = greatest(now(), excluded.availability_observed_at)
+           last_error_reason = null,
+           last_error_message = null,
+           updated_at = greatest(now(), excluded.credential_observed_at)
          returning id",
     )
     .bind(&account.id)
@@ -525,8 +589,8 @@ pub(crate) async fn upsert_provider_account_in_transaction(
     .bind(account.access_token_expires_at)
     .bind(account.next_refresh_at)
     .bind(account.enabled)
-    .bind(availability.as_str())
-    .bind(account.availability_observed_at)
+    .bind(credential_state.as_str())
+    .bind(account.credential_observed_at)
     .fetch_optional(&mut **transaction)
     .await
     .map_err(|error| {
@@ -574,17 +638,17 @@ pub(crate) async fn rotate_provider_account_in_transaction(
              next_refresh_at = $10,
              upstream_user_id = case when $11::boolean then $12::text else upstream_user_id end,
              upstream_account_id = case when $11::boolean then $13::text else upstream_account_id end,
-             availability = case
-                 when not enabled then availability
-                 when availability = 'quota_exhausted' then availability
+             credential_state = case
+                 when not enabled then credential_state
                  when coalesce($12::text, upstream_user_id) is not null then 'ready'
                  else 'unknown'
              end,
-             availability_observed_at = case
-                 when not enabled then availability_observed_at
-                 when availability <> 'quota_exhausted' then now()
-                 else availability_observed_at
+             credential_observed_at = case
+                 when not enabled then credential_observed_at
+                 else now()
              end,
+             last_error_reason = case when enabled then null else last_error_reason end,
+             last_error_message = case when enabled then null else last_error_message end,
              updated_at = now()
          where id = $1 and provider_kind = $2
            and credential_revision = $3
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/rows.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/rows.rs
index af35c670a..ce213471a 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts/rows.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/rows.rs
@@ -65,9 +65,29 @@ impl ProviderAccountAdminScope {
     }
 }
 
-/// 解析数据库 availability 列；字符串映射本体唯一归属 gateway-core。
-pub(crate) fn parse_availability(value: &str) -> StoreResult<AccountAvailability> {
-    AccountAvailability::parse(value).ok_or_else(|| invalid("unknown availability value"))
+pub(crate) fn parse_credential_state(value: &str) -> StoreResult<CredentialState> {
+    CredentialState::parse(value).ok_or_else(|| invalid("unknown credential_state value"))
+}
+
+pub(crate) fn parse_quota_access_state(value: &str) -> StoreResult<QuotaAccessState> {
+    QuotaAccessState::parse(value).ok_or_else(|| invalid("unknown quota_access_state value"))
+}
+
+pub(crate) fn parse_quota_evidence(value: Option<String>) -> StoreResult<Option<QuotaEvidence>> {
+    value
+        .map(|value| {
+            QuotaEvidence::parse(&value).ok_or_else(|| invalid("unknown quota_evidence value"))
+        })
+        .transpose()
+}
+
+pub(crate) fn parse_error_reason(value: Option<String>) -> StoreResult<Option<AccountErrorReason>> {
+    value
+        .map(|value| {
+            AccountErrorReason::parse(&value)
+                .ok_or_else(|| invalid("unknown last_error_reason value"))
+        })
+        .transpose()
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -85,12 +105,10 @@ pub struct ProviderAccountSummary {
     pub access_token_expires_at: Option<DateTime<Utc>>,
     pub next_refresh_at: Option<DateTime<Utc>>,
     pub enabled: bool,
-    pub availability: AccountAvailability,
-    pub availability_observed_at: DateTime<Utc>,
-    pub quota_observed_at: Option<DateTime<Utc>>,
-    /// 快照级限流事实（Provider 物化）。
-    pub quota_limit_reached: bool,
-    /// 最近一次非 ready 状态变更的原始原因（上游错误原文 / 原因码）；恢复 ready 后清空。
+    pub credential_state: CredentialState,
+    pub credential_observed_at: DateTime<Utc>,
+    pub quota: QuotaState,
+    pub last_error_reason: Option<AccountErrorReason>,
     pub last_error_message: Option<String>,
     pub created_at: DateTime<Utc>,
     pub updated_at: DateTime<Utc>,
@@ -132,8 +150,8 @@ pub struct NewProviderAccount {
     pub access_token_expires_at: Option<DateTime<Utc>>,
     pub next_refresh_at: Option<DateTime<Utc>>,
     pub enabled: bool,
-    pub availability: AccountAvailability,
-    pub availability_observed_at: DateTime<Utc>,
+    pub credential_state: CredentialState,
+    pub credential_observed_at: DateTime<Utc>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -152,7 +170,7 @@ impl fmt::Debug for NewProviderAccount {
             .field("provider_kind", &self.provider_kind)
             .field("name", &self.name)
             .field("enabled", &self.enabled)
-            .field("availability", &self.availability)
+            .field("credential_state", &self.credential_state)
             .field("provider_credentials_json", &"[REDACTED]")
             .finish_non_exhaustive()
     }
@@ -297,24 +315,13 @@ impl fmt::Debug for ProviderCredentialUpdate {
     }
 }
 
-#[derive(Debug, Clone, PartialEq)]
-pub struct ProviderAccountObservation {
-    pub account_id: String,
-    pub availability: AccountAvailability,
-    pub provider_quota_json: Option<JsonObject>,
-    pub availability_observed_at: DateTime<Utc>,
-    pub quota_observed_at: Option<DateTime<Utc>>,
-    /// 快照级限流事实（Provider 物化）。
-    pub quota_limit_reached: bool,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ProviderAccountStateUpdate {
     pub account_id: String,
     pub expected_revision: Revision,
-    pub availability: AccountAvailability,
-    pub availability_observed_at: DateTime<Utc>,
-    /// 上游原因（错误原文 / 原因码）；`None` 不更新错误信息列，恢复 `Ready` 时清空。
+    pub credential_state: CredentialState,
+    pub credential_observed_at: DateTime<Utc>,
+    pub error_reason: Option<AccountErrorReason>,
     pub message: Option<String>,
 }
 
@@ -325,31 +332,20 @@ impl ProviderAccountStateUpdate {
     }
 }
 
-impl ProviderAccountObservation {
-    pub fn validate(&self) -> StoreResult<()> {
-        require_nonempty(ENTITY, "account_id", &self.account_id)?;
-        if self.provider_quota_json.is_some() != self.quota_observed_at.is_some() {
-            return Err(invalid("quota JSON and quota_observed_at must agree"));
-        }
-        if let Some(quota) = &self.provider_quota_json {
-            validate_object_size("provider_quota_json", quota, QUOTA_MAX_BYTES)?;
-        }
-        Ok(())
-    }
-}
-
 pub(crate) const ACCOUNT_SELECT: &str = "select id, provider_kind, name, email, upstream_user_id,
             upstream_account_id, plan_type, authentication_kind, provider_credentials_json, credential_revision,
-            has_refresh_token, access_token_expires_at, next_refresh_at, enabled, availability,
-            provider_quota_json, quota_limit_reached, last_error_message,
-            availability_observed_at, quota_observed_at, created_at, updated_at
+            has_refresh_token, access_token_expires_at, next_refresh_at, enabled, credential_state,
+            provider_quota_json, quota_access_state, quota_evidence, quota_access_observed_at, quota_reset_at,
+            last_error_reason, last_error_message,
+            credential_observed_at, quota_observed_at, created_at, updated_at
      from provider_accounts where id = $1";
 
 pub(crate) const ACCOUNT_SELECT_BY_IDS: &str = "select id, provider_kind, name, email, upstream_user_id,
             upstream_account_id, plan_type, authentication_kind, provider_credentials_json, credential_revision,
-            has_refresh_token, access_token_expires_at, next_refresh_at, enabled, availability,
-            provider_quota_json, quota_limit_reached, last_error_message,
-            availability_observed_at, quota_observed_at, created_at, updated_at
+            has_refresh_token, access_token_expires_at, next_refresh_at, enabled, credential_state,
+            provider_quota_json, quota_access_state, quota_evidence, quota_access_observed_at, quota_reset_at,
+            last_error_reason, last_error_message,
+            credential_observed_at, quota_observed_at, created_at, updated_at
      from provider_accounts
      where id = any($1::text[]) and provider_kind = $2
      order by id";
@@ -398,7 +394,13 @@ pub(crate) fn core_account_from_summary(
         summary.upstream_account_id,
         summary.plan_type,
     )
-    .with_runtime_state(summary.enabled, summary.availability)
+    .with_account_facts(
+        summary.enabled,
+        summary.credential_state,
+        summary.quota,
+        summary.last_error_reason,
+        summary.last_error_message,
+    )
     .with_refresh_schedule(
         summary.has_refresh_token,
         summary.next_refresh_at.map(Into::into),
@@ -430,9 +432,20 @@ pub(crate) fn account_summary_from_row(
     let revision = row
         .try_get::<i64, _>("credential_revision")
         .map_err(|_| invalid("invalid credential revision"))?;
-    let availability = row
-        .try_get::<String, _>("availability")
-        .map_err(|_| invalid("invalid availability"))?;
+    let credential_state = row
+        .try_get::<String, _>("credential_state")
+        .map_err(|_| invalid("invalid credential_state"))?;
+    let quota_access_state = parse_quota_access_state(&get::<String>(&row, "quota_access_state")?)?;
+    let quota_evidence = parse_quota_evidence(get(&row, "quota_evidence")?)?;
+    let quota_access_observed_at = get::<Option<DateTime<Utc>>>(&row, "quota_access_observed_at")?;
+    let quota_reset_at = get::<Option<DateTime<Utc>>>(&row, "quota_reset_at")?;
+    let quota = QuotaState::from_persisted(
+        quota_access_state,
+        quota_evidence,
+        quota_access_observed_at.map(Into::into),
+        quota_reset_at.map(Into::into),
+    )
+    .ok_or_else(|| invalid("invalid persisted quota fact"))?;
     Ok(ProviderAccountSummary {
         id: get(&row, "id")?,
         provider_kind: get(&row, "provider_kind")?,
@@ -447,10 +460,10 @@ pub(crate) fn account_summary_from_row(
         access_token_expires_at: get(&row, "access_token_expires_at")?,
         next_refresh_at: get(&row, "next_refresh_at")?,
         enabled: get(&row, "enabled")?,
-        availability: parse_availability(&availability)?,
-        availability_observed_at: get(&row, "availability_observed_at")?,
-        quota_observed_at: get(&row, "quota_observed_at")?,
-        quota_limit_reached: get(&row, "quota_limit_reached")?,
+        credential_state: parse_credential_state(&credential_state)?,
+        credential_observed_at: get(&row, "credential_observed_at")?,
+        quota,
+        last_error_reason: parse_error_reason(get(&row, "last_error_reason")?)?,
         last_error_message: get(&row, "last_error_message")?,
         created_at: get(&row, "created_at")?,
         updated_at: get(&row, "updated_at")?,
diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts/runtime.rs b/backend/crates/gateway-store/src/postgres/provider_accounts/runtime.rs
new file mode 100644
index 000000000..68aff5855
--- /dev/null
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts/runtime.rs
@@ -0,0 +1,53 @@
+//! 持久账号事实与可丢失冷却事实的统一状态投影。
+
+use std::{collections::BTreeMap, time::SystemTime};
+
+use futures::future::join_all;
+use gateway_core::{
+    engine::credential::{
+        AccountStatusFacts, AccountStatusProjection, ProviderAccountId, resolve_account_status,
+    },
+    provider_ports::ProviderCooldownPort,
+};
+
+use super::ProviderAccountSummary;
+
+#[must_use]
+pub(crate) fn account_status_projection(
+    account: &ProviderAccountSummary,
+    now: SystemTime,
+    rate_limited_until: Option<SystemTime>,
+) -> AccountStatusProjection {
+    resolve_account_status(
+        &AccountStatusFacts {
+            enabled: account.enabled,
+            credential_state: account.credential_state,
+            access_token_expires_at: account.access_token_expires_at.map(Into::into),
+            quota: account.quota,
+            rate_limited_until,
+            last_error_reason: account.last_error_reason,
+            last_error_message: account.last_error_message.clone(),
+        },
+        now,
+    )
+}
+
+/// 尽力读取账号当前有效的 429 冷却。
+///
+/// 冷却属于可丢失的账号级运行时事实：端口不可用、单条读取失败或脏账号 ID
+/// 都视为没有冷却，不污染持久账号状态。凭据轮换不会解除上游对同一账号的限流。
+pub(crate) async fn load_rate_limited_until(
+    cooldowns: Option<&dyn ProviderCooldownPort>,
+    accounts: &[ProviderAccountSummary],
+    now: SystemTime,
+) -> BTreeMap<String, SystemTime> {
+    let Some(cooldowns) = cooldowns else {
+        return BTreeMap::new();
+    };
+    let reads = accounts.iter().map(|account| async move {
+        let account_id = ProviderAccountId::new(account.id.clone()).ok()?;
+        let cooldown = cooldowns.read(&account_id).await.ok().flatten()?;
+        (cooldown.until() > now).then(|| (account.id.clone(), cooldown.until()))
+    });
+    join_all(reads).await.into_iter().flatten().collect()
+}
diff --git a/backend/crates/gateway-store/src/postgres/snapshot.rs b/backend/crates/gateway-store/src/postgres/snapshot.rs
index 9d220742d..158ff150d 100644
--- a/backend/crates/gateway-store/src/postgres/snapshot.rs
+++ b/backend/crates/gateway-store/src/postgres/snapshot.rs
@@ -31,7 +31,7 @@ pub struct SnapshotRuntimeSettings {
 pub struct CredentialRevisionVectorEntry {
     pub provider_account_id: String,
     pub credential_revision: Revision,
-    pub availability_observed_at: DateTime<Utc>,
+    pub credential_observed_at: DateTime<Utc>,
     pub quota_observed_at: Option<DateTime<Utc>>,
 }
 
@@ -108,7 +108,7 @@ impl RuntimeSnapshotRepository for PgRuntimeSnapshotRepository {
 
     async fn credential_revision_vector(&self) -> StoreResult<Vec<CredentialRevisionVectorEntry>> {
         let rows = sqlx::query_as::<_, (String, i64, DateTime<Utc>, Option<DateTime<Utc>>)>(
-            "select id, credential_revision, availability_observed_at, quota_observed_at
+            "select id, credential_revision, credential_observed_at, quota_observed_at
              from provider_accounts order by id",
         )
         .fetch_all(&self.pool)
@@ -119,7 +119,7 @@ impl RuntimeSnapshotRepository for PgRuntimeSnapshotRepository {
                 Ok(CredentialRevisionVectorEntry {
                     provider_account_id: row.0,
                     credential_revision: revision_from_i64(row.1)?,
-                    availability_observed_at: row.2,
+                    credential_observed_at: row.2,
                     quota_observed_at: row.3,
                 })
             })
diff --git a/backend/crates/gateway-store/src/redis/credential_leases.rs b/backend/crates/gateway-store/src/redis/credential_leases.rs
index f6b3c24b9..e4090ef66 100644
--- a/backend/crates/gateway-store/src/redis/credential_leases.rs
+++ b/backend/crates/gateway-store/src/redis/credential_leases.rs
@@ -512,7 +512,7 @@ impl RedisProviderLeaseCoordinator {
                         last_started_at: signal.last_started_at.map(Into::into),
                         quota_reset_at: None,
                         quota_remaining_rank: None,
-                        quota_limit_reached: false,
+                        rate_limited_until: None,
                         failure_rate_basis_points: None,
                         first_output_latency_ms: None,
                     },
diff --git a/backend/crates/gateway-store/src/redis/credential_state.rs b/backend/crates/gateway-store/src/redis/credential_state.rs
index d2bc4321b..55f740dcf 100644
--- a/backend/crates/gateway-store/src/redis/credential_state.rs
+++ b/backend/crates/gateway-store/src/redis/credential_state.rs
@@ -1,4 +1,4 @@
-//! Provider account availability 的可重建 Redis cache fence。
+//! Provider credential state 的可重建 Redis cache fence。
 
 use std::time::Duration;
 
@@ -7,7 +7,7 @@ use chrono::{DateTime, Utc};
 use redis::{Script, aio::ConnectionManager};
 
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialRevision, OpaqueProviderData, ProviderAccountId,
+    CredentialRevision, CredentialState, OpaqueProviderData, ProviderAccountId,
 };
 use gateway_core::provider_ports::{
     ProviderCatalogCacheKey, ProviderCatalogCachePort, ProviderCredentialState,
@@ -24,7 +24,7 @@ if current >= tonumber(ARGV[1]) then return 0 end
 redis.call('HSET', KEYS[1],
   'revision', ARGV[1],
   'enabled', ARGV[2],
-  'availability', ARGV[3],
+  'credential_state', ARGV[3],
   'observed_at_ms', ARGV[4])
 redis.call('PEXPIRE', KEYS[1], ARGV[5])
 return 1
@@ -44,7 +44,7 @@ pub struct CredentialStateCache {
     pub provider_account_id: String,
     pub revision: Revision,
     pub enabled: bool,
-    pub availability: String,
+    pub credential_state: String,
     pub observed_at: DateTime<Utc>,
 }
 
@@ -55,8 +55,8 @@ impl CredentialStateCache {
             "provider_account_id",
             &self.provider_account_id,
         )?;
-        if AccountAvailability::parse(&self.availability).is_none() {
-            return Err(invalid("availability is not registered"));
+        if CredentialState::parse(&self.credential_state).is_none() {
+            return Err(invalid("credential_state is not registered"));
         }
         Ok(())
     }
@@ -172,7 +172,7 @@ impl CredentialStateRepository for RedisCredentialStateRepository {
             .key(self.key(&state.provider_account_id)?)
             .arg(state.revision.get())
             .arg(u8::from(state.enabled))
-            .arg(&state.availability)
+            .arg(&state.credential_state)
             .arg(state.observed_at.timestamp_millis())
             .arg(ttl_ms)
             .invoke_async::<i64>(&mut connection)
@@ -195,12 +195,12 @@ impl CredentialStateRepository for RedisCredentialStateRepository {
             .arg(self.key(provider_account_id)?)
             .arg("revision")
             .arg("enabled")
-            .arg("availability")
+            .arg("credential_state")
             .arg("observed_at_ms")
             .query_async(&mut connection)
             .await
             .map_err(|_| redis_unavailable("read credential state"))?;
-        let (Some(revision), Some(enabled), Some(availability), Some(observed_at_ms)) = values
+        let (Some(revision), Some(enabled), Some(credential_state), Some(observed_at_ms)) = values
         else {
             return Ok(None);
         };
@@ -208,7 +208,7 @@ impl CredentialStateRepository for RedisCredentialStateRepository {
             provider_account_id: provider_account_id.to_owned(),
             revision: Revision::new(revision)?,
             enabled: enabled == 1,
-            availability,
+            credential_state,
             observed_at: DateTime::from_timestamp_millis(observed_at_ms)
                 .ok_or_else(|| invalid("observed_at is invalid"))?,
         };
@@ -299,7 +299,7 @@ impl ProviderCredentialStatePort for RedisCredentialStateRepository {
                 revision: Revision::new(state.credential_revision().get())
                     .map_err(|_| provider_invalid("encode credential state"))?,
                 enabled: state.enabled(),
-                availability: state.availability().as_str().to_owned(),
+                credential_state: state.credential_state().as_str().to_owned(),
                 observed_at,
             };
             CredentialStateRepository::cache_credential_state(
@@ -329,13 +329,13 @@ impl ProviderCredentialStatePort for RedisCredentialStateRepository {
                         .map_err(|_| provider_invalid("decode credential state"))?;
                     let revision = CredentialRevision::new(state.revision.get())
                         .map_err(|_| provider_invalid("decode credential state"))?;
-                    let availability = AccountAvailability::parse(&state.availability)
+                    let credential_state = CredentialState::parse(&state.credential_state)
                         .ok_or_else(|| provider_invalid("decode credential state"))?;
                     Ok(ProviderCredentialState::new(
                         account_id,
                         revision,
                         state.enabled,
-                        availability,
+                        credential_state,
                         state.observed_at.into(),
                     ))
                 })
diff --git a/backend/crates/gateway-store/tests/postgres/execution.rs b/backend/crates/gateway-store/tests/postgres/execution.rs
index b7ae28c8e..1a6e8d3fd 100644
--- a/backend/crates/gateway-store/tests/postgres/execution.rs
+++ b/backend/crates/gateway-store/tests/postgres/execution.rs
@@ -55,8 +55,8 @@ async fn merged_first_attempt_insert_should_match_sequential_semantics() {
            id, provider_kind, name, email, upstream_user_id,
            upstream_account_id, plan_type, authentication_kind,
            provider_credentials_json, credential_revision,
-           has_refresh_token, access_token_expires_at, enabled, availability,
-           availability_observed_at, created_at, updated_at
+           has_refresh_token, access_token_expires_at, enabled, credential_state,
+           credential_observed_at, created_at, updated_at
          ) values (
            'acct_merged', 'openai', 'merged', null, 'user-merged', null, null, 'oauth',
            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', $1, $1, $1
diff --git a/backend/crates/gateway-store/tests/postgres/observability.rs b/backend/crates/gateway-store/tests/postgres/observability.rs
index 11d441953..c506487bc 100644
--- a/backend/crates/gateway-store/tests/postgres/observability.rs
+++ b/backend/crates/gateway-store/tests/postgres/observability.rs
@@ -134,26 +134,27 @@ async fn dashboard_account_metrics_should_partition_account_statuses() {
         "insert into provider_accounts (
            id, provider_kind, name, upstream_user_id, authentication_kind,
            provider_credentials_json, credential_revision, has_refresh_token,
-           access_token_expires_at, enabled, availability,
-           availability_observed_at, created_at, updated_at
+           access_token_expires_at, enabled, credential_state,
+           quota_access_state, quota_evidence, quota_access_observed_at,
+           credential_observed_at, created_at, updated_at
          ) values
            ('acct_available', 'openai', 'available', 'user-available', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready',
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_expired', 'openai', 'expired', 'user-expired', 'oauth',
-            '{}'::jsonb, 1, false, $1 - interval '1 day', true, 'ready',
+            '{}'::jsonb, 1, false, $1 - interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_rate_cooldown', 'openai', 'rate-cooldown', 'user-rate-cooldown', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready',
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_usage_limit', 'xai', 'usage-limit', 'user-usage-limit', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'quota_exhausted',
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'exhausted', 'usage_limit_reached', $1,
             $1, $1, $1),
            ('acct_banned', 'xai', 'banned', 'user-banned', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'banned',
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'banned', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_disabled', 'xai', 'disabled', 'user-disabled', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', false, 'ready',
+            '{}'::jsonb, 1, false, $1 + interval '1 day', false, 'ready', 'allowed', null, $1,
             $1, $1, $1)",
     )
     .bind(now)
@@ -173,22 +174,22 @@ async fn dashboard_account_metrics_should_partition_account_statuses() {
     assert_eq!(
         (
             metrics.total,
-            metrics.enabled,
-            metrics.active,
-            metrics.unavailable,
-            metrics.expired,
+            metrics.normal,
             metrics.quota_exhausted,
+            metrics.rate_limited,
             metrics.disabled,
-            metrics.banned,
+            metrics.error,
         ),
-        (6, 5, 2, 4, 1, 1, 1, 1),
+        (6, 2, 1, 0, 1, 2),
     );
-    // 首页按调度可用性聚合：配额耗尽也属于不可用。
     assert_eq!(
-        metrics.unavailable,
-        metrics.quota_exhausted + metrics.expired + metrics.disabled + metrics.banned
+        metrics.total,
+        metrics.normal
+            + metrics.quota_exhausted
+            + metrics.rate_limited
+            + metrics.disabled
+            + metrics.error
     );
-    assert_eq!(metrics.total, metrics.active + metrics.unavailable);
     database.close().await;
 }
 
@@ -202,35 +203,36 @@ async fn dashboard_account_metrics_with_cooldowns_should_only_reclassify_eligibl
         "insert into provider_accounts (
            id, provider_kind, name, upstream_user_id, authentication_kind,
            provider_credentials_json, credential_revision, has_refresh_token,
-           access_token_expires_at, enabled, availability, quota_limit_reached,
-           availability_observed_at, created_at, updated_at
+           access_token_expires_at, enabled, credential_state,
+           quota_access_state, quota_evidence, quota_access_observed_at,
+           credential_observed_at, created_at, updated_at
          ) values
            ('acct_metrics_active', 'openai', 'active', 'user-active', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', false,
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_metrics_active_cooling', 'openai', 'active-cooling', 'user-active-cooling', 'oauth',
-            '{}'::jsonb, 2, false, $1 + interval '1 day', true, 'ready', false,
+            '{}'::jsonb, 2, false, $1 + interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_metrics_ready_quota', 'openai', 'ready-quota', 'user-ready-quota', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', true,
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'exhausted', 'provider_denied', $1,
             $1, $1, $1),
            ('acct_metrics_cooling', 'openai', 'cooling', 'user-cooling', 'oauth',
-            '{}'::jsonb, 3, false, $1 + interval '1 day', true, 'ready', true,
+            '{}'::jsonb, 3, false, $1 + interval '1 day', true, 'ready', 'exhausted', 'provider_denied', $1,
             $1, $1, $1),
            ('acct_metrics_stale_cooldown', 'openai', 'stale-cooldown', 'user-stale-cooldown', 'oauth',
-            '{}'::jsonb, 4, false, $1 + interval '1 day', true, 'ready', true,
+            '{}'::jsonb, 4, false, $1 + interval '1 day', true, 'ready', 'allowed', null, $1,
             $1, $1, $1),
            ('acct_metrics_persistent_quota', 'openai', 'persistent-quota', 'user-persistent-quota', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'quota_exhausted', true,
+            '{}'::jsonb, 1, false, $1 + interval '1 day', true, 'ready', 'exhausted', 'provider_denied', $1,
             $1, $1, $1),
            ('acct_metrics_expired', 'openai', 'expired', 'user-expired', 'oauth',
-            '{}'::jsonb, 5, false, $1 - interval '1 second', true, 'ready', true,
+            '{}'::jsonb, 5, false, $1 - interval '1 second', true, 'ready', 'exhausted', 'provider_denied', $1,
             $1, $1, $1),
            ('acct_metrics_unknown', 'openai', 'unknown', 'user-unknown', 'oauth',
-            '{}'::jsonb, 6, false, $1 + interval '1 day', true, 'unknown', false,
+            '{}'::jsonb, 6, false, $1 + interval '1 day', true, 'unknown', 'unknown', null, null,
             $1, $1, $1),
            ('acct_metrics_disabled', 'openai', 'disabled', 'user-disabled', 'oauth',
-            '{}'::jsonb, 1, false, $1 + interval '1 day', false, 'ready', false,
+            '{}'::jsonb, 1, false, $1 + interval '1 day', false, 'ready', 'allowed', null, $1,
             $1, $1, $1)",
     )
     .bind(now)
@@ -258,36 +260,21 @@ async fn dashboard_account_metrics_with_cooldowns_should_only_reclassify_eligibl
     assert_eq!(
         (
             metrics.total,
-            metrics.enabled,
-            metrics.active,
+            metrics.normal,
             metrics.rate_limited,
             metrics.quota_exhausted,
-            metrics.expired,
-            metrics.invalid,
             metrics.disabled,
-            metrics.banned,
-            metrics.unavailable,
+            metrics.error,
         ),
-        (9, 8, 1, 2, 3, 1, 1, 1, 0, 8),
+        (9, 1, 2, 3, 1, 2),
     );
     assert_eq!(
         metrics.total,
-        metrics.active
+        metrics.normal
             + metrics.rate_limited
             + metrics.quota_exhausted
-            + metrics.expired
-            + metrics.invalid
             + metrics.disabled
-            + metrics.banned
-    );
-    assert_eq!(
-        metrics.unavailable,
-        metrics.rate_limited
-            + metrics.quota_exhausted
-            + metrics.expired
-            + metrics.invalid
-            + metrics.disabled
-            + metrics.banned
+            + metrics.error
     );
     database.close().await;
 }
@@ -1013,8 +1000,8 @@ async fn seed_observability_facts(
            id, provider_kind, name, email, upstream_user_id,
            upstream_account_id, plan_type, authentication_kind,
            provider_credentials_json, credential_revision,
-           has_refresh_token, access_token_expires_at, enabled, availability,
-           availability_observed_at, created_at, updated_at
+           has_refresh_token, access_token_expires_at, enabled, credential_state,
+           credential_observed_at, created_at, updated_at
          ) values (
            'acct_observe', 'openai', 'primary', 'account@example.invalid',
            'user-observe', null, 'pro', 'oauth', '{}'::jsonb, 1, false, $1 + interval '1 day',
diff --git a/backend/crates/gateway-store/tests/postgres/provider_accounts.rs b/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
index 7b1253172..9b4d7855b 100644
--- a/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
+++ b/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
@@ -10,16 +10,15 @@ use gateway_admin::{
             SortDirection,
         },
         observability::TimeRange,
-        provider_credentials::{
-            CredentialAvailabilityFilter, CredentialListQuery, CredentialListWindow,
-        },
+        provider_credentials::{CredentialListQuery, CredentialListWindow, CredentialStateFilter},
     },
     ports::store::AccountStore,
 };
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
-    CredentialRevision, OpaqueProviderData, PlaintextCredential, ProviderAccountId,
-    ProviderAccountIdentity, ProviderAccountStore, ProviderAccountUpdate, QuotaObservation,
+    AccountErrorReason, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
+    CredentialRevision, CredentialState, OpaqueProviderData, PlaintextCredential,
+    ProviderAccountId, ProviderAccountIdentity, ProviderAccountStore, ProviderAccountUpdate,
+    QuotaAccessChange, QuotaAccessState, QuotaEvidence, QuotaObservation, QuotaState,
     QuotaWriteOutcome,
 };
 use gateway_core::routing::ProviderKind;
@@ -59,7 +58,7 @@ async fn provider_account_should_allow_missing_upstream_user_id() {
     let mut pending = account("acct_pending_identity", "unused");
     pending.upstream_user_id = None;
     pending.email = None;
-    pending.availability = AccountAvailability::Ready;
+    pending.credential_state = CredentialState::Ready;
     repository
         .insert_provider_account(pending)
         .await
@@ -71,8 +70,11 @@ async fn provider_account_should_allow_missing_upstream_user_id() {
         .expect("load account")
         .expect("stored account");
     assert_eq!(
-        (stored.summary.upstream_user_id, stored.summary.availability,),
-        (None, AccountAvailability::Unknown)
+        (
+            stored.summary.upstream_user_id,
+            stored.summary.credential_state,
+        ),
+        (None, CredentialState::Unknown)
     );
 
     database.close().await;
@@ -92,18 +94,19 @@ async fn core_quota_batch_reads_only_observed_accounts_in_one_contract_call() {
     }
     let revision = CredentialRevision::new(1).expect("revision");
     for (id, remaining) in [("acct_quota_a", 20), ("acct_quota_b", 80)] {
+        let observed_at = SystemTime::now();
         let outcome = repository
             .compare_and_swap_quota(QuotaObservation {
                 account_id: ProviderAccountId::new(id).expect("account id"),
                 expected_revision: revision,
-                quota: Some(OpaqueProviderData::new(
+                quota: OpaqueProviderData::new(
                     json!({"remaining": remaining})
                         .as_object()
                         .expect("quota object")
                         .clone(),
-                )),
-                observed_at: Some(SystemTime::now()),
-                limit_reached: None,
+                ),
+                observed_at,
+                state: QuotaState::allowed(observed_at),
             })
             .await
             .expect("persist quota");
@@ -123,15 +126,12 @@ async fn core_quota_batch_reads_only_observed_accounts_in_one_contract_call() {
     assert_eq!(observations.len(), 2);
     assert_eq!(observations[0].account_id.as_str(), "acct_quota_a");
     assert_eq!(observations[0].expected_revision, revision);
-    assert_eq!(
-        observations[0]
-            .quota
-            .as_ref()
-            .expect("quota")
-            .expose_to_provider()["remaining"],
-        20
+    assert_eq!(observations[0].quota.expose_to_provider()["remaining"], 20);
+    assert!(
+        observations
+            .iter()
+            .all(|value| value.state.access() == QuotaAccessState::Allowed)
     );
-    assert!(observations.iter().all(|value| value.observed_at.is_some()));
     assert_eq!(
         current_revision(&database.pool).await,
         1,
@@ -163,14 +163,14 @@ async fn delayed_provider_observations_cannot_overwrite_newer_state_or_quota() {
     let quota = |marker: &str, observed_at| QuotaObservation {
         account_id: account_id.clone(),
         expected_revision: revision,
-        quota: Some(OpaqueProviderData::new(
+        quota: OpaqueProviderData::new(
             json!({"marker": marker})
                 .as_object()
                 .expect("quota object")
                 .clone(),
-        )),
-        observed_at: Some(observed_at),
-        limit_reached: None,
+        ),
+        observed_at,
+        state: QuotaState::allowed(observed_at),
     };
     assert_eq!(
         repository
@@ -192,8 +192,9 @@ async fn delayed_provider_observations_cannot_overwrite_newer_state_or_quota() {
             message: None,
             account_id: account_id.clone(),
             expected_revision: revision,
-            availability: AccountAvailability::QuotaExhausted,
+            credential_state: CredentialState::Invalid,
             observed_at: newer,
+            error_reason: Some(AccountErrorReason::CredentialInvalid),
         })
         .await
         .expect("persist newer account state");
@@ -203,8 +204,9 @@ async fn delayed_provider_observations_cannot_overwrite_newer_state_or_quota() {
                 message: None,
                 account_id: account_id.clone(),
                 expected_revision: revision,
-                availability: AccountAvailability::Ready,
+                credential_state: CredentialState::Ready,
                 observed_at: older,
+                error_reason: None,
             })
             .await
             .is_err(),
@@ -216,23 +218,20 @@ async fn delayed_provider_observations_cannot_overwrite_newer_state_or_quota() {
         .await
         .expect("load fenced account")
         .expect("fenced account");
-    assert_eq!(current.availability(), AccountAvailability::QuotaExhausted);
+    assert_eq!(current.credential_state(), CredentialState::Invalid);
     let observed = repository
         .get_quotas(std::slice::from_ref(&account_id))
         .await
         .expect("load fenced quota")
         .pop()
         .expect("fenced quota");
-    assert_eq!(
-        observed.quota.expect("quota document").expose_to_provider()["marker"],
-        "newer"
-    );
+    assert_eq!(observed.quota.expose_to_provider()["marker"], "newer");
 
     database.close().await;
 }
 
 #[tokio::test]
-async fn account_state_message_is_persisted_and_cleared_on_recovery() {
+async fn credential_error_message_is_persisted_and_cleared_on_recovery() {
     let Some(database) = TestDatabase::create("provider_account_state_message").await else {
         return;
     };
@@ -249,8 +248,9 @@ async fn account_state_message_is_persisted_and_cleared_on_recovery() {
             message: Some("upstream returned 402 payment required".to_owned()),
             account_id: account_id.clone(),
             expected_revision: revision,
-            availability: AccountAvailability::QuotaExhausted,
+            credential_state: CredentialState::Invalid,
             observed_at: SystemTime::now(),
+            error_reason: Some(AccountErrorReason::CredentialInvalid),
         })
         .await
         .expect("persist error message");
@@ -270,8 +270,9 @@ async fn account_state_message_is_persisted_and_cleared_on_recovery() {
             message: None,
             account_id: account_id.clone(),
             expected_revision: revision,
-            availability: AccountAvailability::Ready,
+            credential_state: CredentialState::Ready,
             observed_at: SystemTime::now(),
+            error_reason: None,
         })
         .await
         .expect("recover account");
@@ -299,39 +300,34 @@ async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_u
     let mut beta = account("acct_beta", "user-beta");
     beta.provider_kind = "xai".to_owned();
     beta.email = Some("beta@example.invalid".to_owned());
-    beta.availability = AccountAvailability::Banned;
+    beta.credential_state = CredentialState::Banned;
     let mut charlie = account("acct_charlie", "user-charlie");
     charlie.email = Some("charlie@example.invalid".to_owned());
     let mut invalid = account("acct_invalid", "user-invalid");
     invalid.email = Some("invalid@example.invalid".to_owned());
-    invalid.availability = AccountAvailability::Invalid;
+    invalid.credential_state = CredentialState::Invalid;
     let mut disabled = account("acct_disabled", "user-disabled");
     disabled.email = Some("disabled@example.invalid".to_owned());
     disabled.enabled = false;
     let mut quota_exhausted = account("acct_quota_exhausted", "user-quota-exhausted");
     quota_exhausted.email = Some("quota-exhausted@example.invalid".to_owned());
-    quota_exhausted.availability = AccountAvailability::QuotaExhausted;
     for account in [alpha, beta, charlie, invalid, disabled, quota_exhausted] {
         repository
             .insert_provider_account(account)
             .await
             .expect("insert account list fixture");
     }
-    repository
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: ProviderAccountId::new("acct_charlie").expect("account id"),
-            expected_revision: CredentialRevision::new(1).expect("credential revision"),
-            quota: Some(OpaqueProviderData::new(
-                json!({"rate_limit": {"limit_reached": true}})
-                    .as_object()
-                    .expect("quota object")
-                    .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: Some(true),
-        })
-        .await
-        .expect("seed rate-limited account");
+    for account_id in ["acct_charlie", "acct_quota_exhausted"] {
+        let observed_at = SystemTime::now();
+        repository
+            .apply_quota_access(QuotaAccessChange {
+                account_id: ProviderAccountId::new(account_id).expect("account id"),
+                expected_revision: CredentialRevision::new(1).expect("credential revision"),
+                state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
+            })
+            .await
+            .expect("seed exhausted account");
+    }
 
     seed_model_request(
         &database.pool,
@@ -425,7 +421,7 @@ async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_u
         usage_page
             .items
             .iter()
-            .map(|account| account.id.as_str())
+            .map(|item| item.account.id.as_str())
             .collect::<Vec<_>>(),
         ["acct_charlie", "acct_beta"]
     );
@@ -448,7 +444,7 @@ async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_u
         last_used_page
             .items
             .iter()
-            .map(|account| account.id.as_str())
+            .map(|item| item.account.id.as_str())
             .collect::<Vec<_>>(),
         ["acct_beta", "acct_charlie"]
     );
@@ -466,8 +462,8 @@ async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_u
         .expect("filter account directory");
     assert_eq!(filtered.total, 1);
     assert_eq!(filtered.summary, usage_page.summary);
-    assert_eq!(filtered.items[0].id, "acct_alpha");
-    assert_eq!(filtered.items[0].provider_kind.as_str(), "openai");
+    assert_eq!(filtered.items[0].account.id, "acct_alpha");
+    assert_eq!(filtered.items[0].account.provider_kind.as_str(), "openai");
 
     let error_accounts = store
         .list_accounts(AccountListQuery {
@@ -481,8 +477,8 @@ async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_u
         .await
         .expect("filter error accounts");
     assert_eq!(error_accounts.items.len(), 2);
-    assert_eq!(error_accounts.items[0].id, "acct_beta");
-    assert_eq!(error_accounts.items[1].id, "acct_invalid");
+    assert_eq!(error_accounts.items[0].account.id, "acct_beta");
+    assert_eq!(error_accounts.items[1].account.id, "acct_invalid");
     database.close().await;
 }
 
@@ -498,11 +494,11 @@ async fn terminal_credential_list_preserves_grouped_filters_and_unpaged_collecti
             &format!("user-xai-{index:03}"),
         );
         credential.provider_kind = "xai".to_owned();
-        credential.availability = match index {
-            0 => AccountAvailability::Expired,
-            1 => AccountAvailability::Banned,
-            2 => AccountAvailability::Invalid,
-            _ => AccountAvailability::Ready,
+        credential.credential_state = match index {
+            0 => CredentialState::Expired,
+            1 => CredentialState::Banned,
+            2 => CredentialState::Invalid,
+            _ => CredentialState::Ready,
         };
         repository
             .insert_provider_account(credential)
@@ -516,7 +512,7 @@ async fn terminal_credential_list_preserves_grouped_filters_and_unpaged_collecti
         .list_credentials(
             &provider,
             CredentialListQuery {
-                availability: None,
+                credential_state: None,
                 enabled: None,
                 window: CredentialListWindow::All,
             },
@@ -530,7 +526,7 @@ async fn terminal_credential_list_preserves_grouped_filters_and_unpaged_collecti
         .list_credentials(
             &provider,
             CredentialListQuery {
-                availability: None,
+                credential_state: None,
                 enabled: None,
                 window: CredentialListWindow::Page {
                     cursor: None,
@@ -547,10 +543,10 @@ async fn terminal_credential_list_preserves_grouped_filters_and_unpaged_collecti
         .list_credentials(
             &provider,
             CredentialListQuery {
-                availability: Some(CredentialAvailabilityFilter::AnyOf(vec![
-                    gateway_admin::model::accounts::AccountAvailability::Expired,
-                    gateway_admin::model::accounts::AccountAvailability::Banned,
-                    gateway_admin::model::accounts::AccountAvailability::Invalid,
+                credential_state: Some(CredentialStateFilter::AnyOf(vec![
+                    CredentialState::Expired,
+                    CredentialState::Banned,
+                    CredentialState::Invalid,
                 ])),
                 enabled: None,
                 window: CredentialListWindow::All,
@@ -851,7 +847,7 @@ async fn admin_import_updates_the_same_verified_identity_without_rebinding_it()
     let mut updated = account("acct_admin_reimport", "user-admin-upsert");
     updated.name = "updated import".to_owned();
     updated.provider_credentials_json = credential_json("updated-import-secret");
-    updated.availability = AccountAvailability::Banned;
+    updated.credential_state = CredentialState::Banned;
     let imported = repository
         .import_provider_accounts(ImportProviderAccounts {
             scope: scope.clone(),
@@ -871,7 +867,7 @@ async fn admin_import_updates_the_same_verified_identity_without_rebinding_it()
         String,
     ) = sqlx::query_as(
         "select name, provider_credentials_json, credential_revision, provider_quota_json,
-                availability
+                credential_state
          from provider_accounts where id = 'acct_admin_upsert'",
     )
     .fetch_one(&database.pool)
@@ -920,8 +916,8 @@ async fn core_refresh_cas_updates_profile_and_credential_under_one_revision() {
             access_token_expires_at: Some(Utc::now() + TimeDelta::minutes(5)),
             next_refresh_at: None,
             enabled: true,
-            availability: AccountAvailability::Ready,
-            availability_observed_at: Utc::now(),
+            credential_state: CredentialState::Ready,
+            credential_observed_at: Utc::now(),
         })
         .await
         .expect("seed provider account");
@@ -1041,32 +1037,32 @@ async fn provider_account_admin_mutations_are_scoped_audited_and_atomic() {
         provider_kind: "openai".to_owned(),
     };
 
-    let mut cooldown_account = account("acct_admin_b", "user-admin-b");
-    cooldown_account.availability = AccountAvailability::Ready;
     let imported = repository
         .import_provider_accounts(ImportProviderAccounts {
             scope: scope.clone(),
-            accounts: vec![account("acct_admin_a", "user-admin-a"), cooldown_account],
+            accounts: vec![
+                account("acct_admin_a", "user-admin-a"),
+                account("acct_admin_b", "user-admin-b"),
+            ],
             audit: audit("audit_account_batch", "import_batch", "provider_accounts"),
         })
         .await
         .expect("import provider accounts");
     assert_eq!(imported.config_revision.get(), 2);
     let ready: (bool, String) =
-        sqlx::query_as("select enabled, availability from provider_accounts where id = $1")
+        sqlx::query_as("select enabled, credential_state from provider_accounts where id = $1")
             .bind("acct_admin_a")
             .fetch_one(&database.pool)
             .await
             .expect("load ready imported account");
     assert_eq!(ready, (true, "ready".to_owned()));
-    let cooldown: (bool, String) =
-        sqlx::query_as("select enabled, availability from provider_accounts where id = $1")
+    let second: (bool, String) =
+        sqlx::query_as("select enabled, credential_state from provider_accounts where id = $1")
             .bind("acct_admin_b")
             .fetch_one(&database.pool)
             .await
             .expect("load cooldown imported account");
-    assert!(cooldown.0);
-    assert_eq!(cooldown.1, "ready");
+    assert_eq!(second, (true, "ready".to_owned()));
 
     repository
         .import_provider_accounts(ImportProviderAccounts {
@@ -1113,7 +1109,7 @@ async fn provider_account_admin_mutations_are_scoped_audited_and_atomic() {
 
     sqlx::query(
         "update provider_accounts
-         set availability = 'expired'
+         set credential_state = 'expired'
          where id = $1",
     )
     .bind("acct_admin_a")
@@ -1137,7 +1133,7 @@ async fn provider_account_admin_mutations_are_scoped_audited_and_atomic() {
     assert_eq!(rotation.config_revision.get(), 3);
     assert_eq!(rotation.credential_revision.get(), 2);
     let restored: (String, String, Option<String>) = sqlx::query_as(
-        "select availability, upstream_user_id, upstream_account_id
+        "select credential_state, upstream_user_id, upstream_account_id
          from provider_accounts where id = $1",
     )
     .bind("acct_admin_a")
@@ -1243,12 +1239,10 @@ async fn verified_credential_rotation_preserves_quota_exhaustion() {
     let scope = ProviderAccountAdminScope {
         provider_kind: "openai".to_owned(),
     };
-    let mut exhausted = account("acct_rotation_quota", "user-rotation-quota");
-    exhausted.availability = AccountAvailability::QuotaExhausted;
     repository
         .import_provider_accounts(ImportProviderAccounts {
             scope: scope.clone(),
-            accounts: vec![exhausted],
+            accounts: vec![account("acct_rotation_quota", "user-rotation-quota")],
             audit: audit(
                 "audit_rotation_quota_import",
                 "import",
@@ -1257,6 +1251,15 @@ async fn verified_credential_rotation_preserves_quota_exhaustion() {
         })
         .await
         .expect("import exhausted account");
+    let observed_at = SystemTime::now();
+    repository
+        .apply_quota_access(QuotaAccessChange {
+            account_id: ProviderAccountId::new("acct_rotation_quota").expect("account ID"),
+            expected_revision: CredentialRevision::new(1).expect("credential revision"),
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
+        })
+        .await
+        .expect("persist quota exhaustion");
 
     repository
         .rotate_provider_account(RotateProviderAccount {
@@ -1273,13 +1276,13 @@ async fn verified_credential_rotation_preserves_quota_exhaustion() {
         .await
         .expect("rotate exhausted account credential");
 
-    let availability: String =
-        sqlx::query_scalar("select availability from provider_accounts where id = $1")
+    let quota_access_state: String =
+        sqlx::query_scalar("select quota_access_state from provider_accounts where id = $1")
             .bind("acct_rotation_quota")
             .fetch_one(&database.pool)
             .await
             .expect("load exhausted account after credential rotation");
-    assert_eq!(availability, "quota_exhausted".to_owned());
+    assert_eq!(quota_access_state, "exhausted".to_owned());
 
     database.close().await;
 }
@@ -1298,26 +1301,25 @@ async fn xai_free_quota_exhaustion_state_is_persisted() {
         .await
         .expect("insert xAI account");
 
+    let observed_at = SystemTime::now();
     repository
-        .apply_state_change(AccountStateChange {
-            message: None,
+        .apply_quota_access(QuotaAccessChange {
             account_id: account_id.clone(),
             expected_revision: CredentialRevision::new(1).expect("credential revision"),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
+            state: QuotaState::exhausted(QuotaEvidence::AccountLimitReached, observed_at, None),
         })
         .await
         .expect("persist xAI free quota exhaustion");
 
     let current: (String, String) = sqlx::query_as(
-        "select provider_kind, availability
+        "select provider_kind, quota_access_state
          from provider_accounts where id = $1",
     )
     .bind(account_id.as_str())
     .fetch_one(&database.pool)
     .await
     .expect("load persisted xAI quota state");
-    assert_eq!(current, ("xai".to_owned(), "quota_exhausted".to_owned()),);
+    assert_eq!(current, ("xai".to_owned(), "exhausted".to_owned()),);
 
     database.close().await;
 }
@@ -1338,25 +1340,29 @@ async fn xai_resettable_usage_limit_state_is_persisted() {
 
     let observed_at = SystemTime::now();
     repository
-        .apply_state_change(AccountStateChange {
-            message: None,
+        .apply_quota_access(QuotaAccessChange {
             account_id: account_id.clone(),
             expected_revision: CredentialRevision::new(1).expect("credential revision"),
-            availability: AccountAvailability::Ready,
-            observed_at,
+            state: QuotaState::exhausted(
+                QuotaEvidence::UsageLimitReached,
+                observed_at,
+                Some(observed_at + Duration::from_secs(60)),
+            ),
         })
         .await
         .expect("persist xAI resettable usage limit");
 
-    let current: (String, String) = sqlx::query_as(
-        "select provider_kind, availability
+    let current: (String, String, Option<chrono::DateTime<Utc>>) = sqlx::query_as(
+        "select provider_kind, quota_access_state, quota_reset_at
          from provider_accounts where id = $1",
     )
     .bind(account_id.as_str())
     .fetch_one(&database.pool)
     .await
     .expect("load persisted xAI usage limit state");
-    assert_eq!(current, ("xai".to_owned(), "ready".to_owned()));
+    assert_eq!(current.0, "xai");
+    assert_eq!(current.1, "exhausted");
+    assert!(current.2.is_some());
 
     database.close().await;
 }
@@ -1373,7 +1379,7 @@ async fn disabled_account_preserves_user_state_during_refresh_writes() {
     let account_id = ProviderAccountId::new("acct_disabled_refresh").expect("account ID");
     let mut disabled = account(account_id.as_str(), "user-disabled-refresh");
     disabled.enabled = false;
-    disabled.availability = AccountAvailability::Expired;
+    disabled.credential_state = CredentialState::Expired;
     repository
         .import_provider_accounts(ImportProviderAccounts {
             scope: scope.clone(),
@@ -1392,8 +1398,9 @@ async fn disabled_account_preserves_user_state_during_refresh_writes() {
             message: None,
             account_id: account_id.clone(),
             expected_revision: CredentialRevision::new(1).expect("credential revision"),
-            availability: AccountAvailability::Ready,
+            credential_state: CredentialState::Ready,
             observed_at: SystemTime::now(),
+            error_reason: None,
         })
         .await
         .expect("disabled state write is a no-op");
@@ -1413,7 +1420,7 @@ async fn disabled_account_preserves_user_state_during_refresh_writes() {
         .expect("refresh disabled account credential");
 
     let current: (bool, String, serde_json::Value, i64) = sqlx::query_as(
-        "select enabled, availability, provider_credentials_json, credential_revision
+        "select enabled, credential_state, provider_credentials_json, credential_revision
          from provider_accounts where id = $1",
     )
     .bind(account_id.as_str())
@@ -1443,8 +1450,8 @@ fn account(id: &str, upstream_user_id: &str) -> NewProviderAccount {
         access_token_expires_at: Some(Utc::now() + TimeDelta::hours(1)),
         next_refresh_at: None,
         enabled: true,
-        availability: AccountAvailability::Ready,
-        availability_observed_at: Utc::now(),
+        credential_state: CredentialState::Ready,
+        credential_observed_at: Utc::now(),
     }
 }
 
@@ -1570,13 +1577,6 @@ fn provider_credentials_are_redacted_from_debug() {
     assert!(!format!("{object:?}").contains(secret));
 }
 
-#[test]
-fn quota_exhausted_account_accepts_cooldown_runtime_facts() {
-    let mut imported = account("acct_quota_cooldown", "user-quota-cooldown");
-    imported.availability = AccountAvailability::QuotaExhausted;
-    assert!(imported.validate().is_ok());
-}
-
 #[test]
 fn imported_ready_account_passes_validation() {
     let imported = account("acct_ready_import", "user-ready-import");
diff --git a/backend/crates/gateway-store/tests/postgres/runtime_settings.rs b/backend/crates/gateway-store/tests/postgres/runtime_settings.rs
index 11b02ba99..55a9143e5 100644
--- a/backend/crates/gateway-store/tests/postgres/runtime_settings.rs
+++ b/backend/crates/gateway-store/tests/postgres/runtime_settings.rs
@@ -108,7 +108,7 @@ async fn insert_refreshable_account(
         "insert into provider_accounts (
            id, provider_kind, name, upstream_user_id, authentication_kind,
            provider_credentials_json, has_refresh_token, access_token_expires_at,
-           next_refresh_at, availability, availability_observed_at, created_at, updated_at
+           next_refresh_at, credential_state, credential_observed_at, created_at, updated_at
          ) values ($1, 'openai', $1, $1, 'oauth', '{}'::jsonb, true, $2, $3,
                    'ready', now(), now(), now())",
     )
diff --git a/backend/crates/gateway-store/tests/postgres/snapshots.rs b/backend/crates/gateway-store/tests/postgres/snapshots.rs
index e8467d937..7b43a7a83 100644
--- a/backend/crates/gateway-store/tests/postgres/snapshots.rs
+++ b/backend/crates/gateway-store/tests/postgres/snapshots.rs
@@ -722,8 +722,8 @@ async fn seed_account(
            id, provider_kind, name, email, upstream_user_id,
            upstream_account_id, plan_type, authentication_kind,
            provider_credentials_json, credential_revision,
-           has_refresh_token, access_token_expires_at, enabled, availability,
-           availability_observed_at, created_at, updated_at
+           has_refresh_token, access_token_expires_at, enabled, credential_state,
+           credential_observed_at, created_at, updated_at
          ) values (
            $1, 'openai', $2, $3, 'user-' || $1, null, null, $4,
            '{}'::jsonb, 1, false, $5 + interval '1 day', true, 'ready',
diff --git a/backend/crates/gateway-store/tests/redis/credential_state.rs b/backend/crates/gateway-store/tests/redis/credential_state.rs
index 39d97d4dc..71c27c0ca 100644
--- a/backend/crates/gateway-store/tests/redis/credential_state.rs
+++ b/backend/crates/gateway-store/tests/redis/credential_state.rs
@@ -19,7 +19,7 @@ fn credential_state_rejects_provider_specific_status() {
         provider_account_id: "account-1".to_owned(),
         revision: Revision::new(1).expect("positive revision"),
         enabled: true,
-        availability: "codex_special".to_owned(),
+        credential_state: "codex_special".to_owned(),
         observed_at: Utc::now(),
     };
     assert!(state.validate().is_err());
diff --git a/backend/crates/providers/openai/src/admin.rs b/backend/crates/providers/openai/src/admin.rs
index a63906458..1bc659587 100644
--- a/backend/crates/providers/openai/src/admin.rs
+++ b/backend/crates/providers/openai/src/admin.rs
@@ -25,9 +25,8 @@ use gateway_admin::model::{MutationActor, MutationContext, Revision};
 use gateway_admin::ports::provider::{ProviderAdmin, ProviderAdminError, ProviderAdminErrorKind};
 use gateway_core::accounting::Money;
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialRevision, LoadedCredential, NewProviderAccount,
-    OpaqueProviderData, PlaintextCredential, ProviderAccount, ProviderAccountId,
-    ProviderAccountStore,
+    CredentialRevision, LoadedCredential, NewProviderAccount, OpaqueProviderData,
+    PlaintextCredential, ProviderAccount, ProviderAccountId, ProviderAccountStore,
 };
 use gateway_core::error::StoreErrorKind;
 use gateway_core::operation::{GenerateRequest, Operation, ProtocolPayload};
@@ -424,14 +423,7 @@ impl ProviderAdmin for OpenAiAdminProvider {
                 .await
                 .map_err(map_quota_error)?
         };
-        let mut quota = project_quota(snapshot, &account);
-        quota.rate_limited_until = self
-            .quota
-            .rate_limited_until(account.id(), account.revision())
-            .await
-            .map_err(map_quota_error)?
-            .map(DateTime::<Utc>::from);
-        Ok(quota)
+        Ok(project_quota(snapshot, &account))
     }
 
     async fn models(
@@ -519,7 +511,6 @@ fn prepared_create(
         account,
         credential,
     } = prepared;
-    let availability = account.availability();
     Ok(PreparedCredentialCreate {
         account_id: account.id().clone(),
         provider_kind: account.provider().clone(),
@@ -534,8 +525,8 @@ fn prepared_create(
         access_token_expires_at: account.access_token_expires_at().map(DateTime::<Utc>::from),
         next_refresh_at: account.next_refresh_at().map(DateTime::<Utc>::from),
         enabled: account.enabled(),
-        availability,
-        availability_observed_at: observed_at,
+        credential_state: account.credential_state(),
+        credential_observed_at: observed_at,
     })
 }
 
@@ -627,7 +618,13 @@ fn account_from_record(account: &AccountRecord) -> Result<ProviderAccount, Provi
         account.upstream_account_id.clone(),
         account.plan_type.clone(),
     )
-    .with_runtime_state(account.enabled, account.availability)
+    .with_account_facts(
+        account.enabled,
+        account.credential_state,
+        account.quota,
+        account.last_error_reason,
+        account.last_error_message.clone(),
+    )
     .with_refresh_schedule(
         account.has_refresh_token,
         account.next_refresh_at.map(SystemTime::from),
@@ -687,7 +684,6 @@ fn empty_quota() -> ProviderQuota {
         refresh_token_expires_at: None,
         windows: Vec::new(),
         limit_reached: false,
-        rate_limited_until: None,
         provider_data: None,
     }
 }
@@ -696,13 +692,10 @@ fn project_quota(
     snapshot: Option<CodexAccountQuotaSnapshot>,
     account: &ProviderAccount,
 ) -> ProviderQuota {
-    // 展示前先滚动已过期窗口，避免 reset 后的旧窗口值悬挂。
     let mut quota = snapshot
-        .map(|snapshot| project_quota_snapshot(snapshot.roll_expired_windows(SystemTime::now())))
+        .map(project_quota_snapshot)
         .unwrap_or_else(empty_quota);
-    if account.availability() == AccountAvailability::QuotaExhausted {
-        force_confirmed_exhaustion_projection(&mut quota);
-    }
+    quota.limit_reached = account.quota().is_exhausted();
     quota
 }
 
@@ -717,7 +710,7 @@ fn project_quota_snapshot(snapshot: CodexAccountQuotaSnapshot) -> ProviderQuota
     );
     provider_data.insert(
         "exhausted".to_owned(),
-        Value::Bool(snapshot.fact().exhausted()),
+        Value::Bool(snapshot.quota().is_exhausted()),
     );
     let windows: Vec<ProviderQuotaWindow> = snapshot
         .windows()
@@ -766,7 +759,6 @@ fn project_quota_snapshot(snapshot: CodexAccountQuotaSnapshot) -> ProviderQuota
         refresh_token_expires_at: None,
         windows,
         limit_reached,
-        rate_limited_until: None,
         provider_data: Some(ProviderDocument::new(OpaqueProviderData::new(
             provider_data,
         ))),
@@ -788,52 +780,6 @@ fn quota_windows_limit_reached(windows: &[ProviderQuotaWindow]) -> bool {
     windows.iter().any(|window| window.limit_reached)
 }
 
-fn force_confirmed_exhaustion_projection(quota: &mut ProviderQuota) {
-    // 402 已确认耗尽：只覆盖 Admin 展示投影，原始 Provider JSON 仍作为
-    // 后续判断窗口是否真正恢复的基线。
-    quota.limit_reached = true;
-    quota.provider_data = Some(ProviderDocument::new(OpaqueProviderData::new(
-        Map::from_iter([
-            (
-                "remaining_percent".to_owned(),
-                Value::Number(Number::from(0)),
-            ),
-            ("exhausted".to_owned(), Value::Bool(true)),
-        ]),
-    )));
-    if quota.windows.is_empty() {
-        quota.windows.push(ProviderQuotaWindow {
-            key: "confirmed-quota-exhaustion".to_owned(),
-            group: "other".to_owned(),
-            label: "额度".to_owned(),
-            source: None,
-            local_usage_attribution: QuotaLocalUsageAttribution::Unavailable,
-            window_seconds: None,
-            used_percent: Some(100.0),
-            reset_at: None,
-            limit_reached: true,
-            local_usage: None,
-            provider_data: None,
-        });
-        return;
-    }
-
-    // 选已用比例最高的窗口强制 100%，保留其自身 reset_at。
-    let index = quota
-        .windows
-        .iter()
-        .enumerate()
-        .max_by(|(_, left), (_, right)| {
-            left.used_percent
-                .unwrap_or(-1.0)
-                .total_cmp(&right.used_percent.unwrap_or(-1.0))
-        })
-        .map(|(index, _)| index)
-        .unwrap_or(0);
-    quota.windows[index].used_percent = Some(100.0);
-    quota.windows[index].limit_reached = true;
-}
-
 const fn quota_group(kind: CodexQuotaWindowKind) -> &'static str {
     match kind {
         CodexQuotaWindowKind::Monthly => "monthly",
diff --git a/backend/crates/providers/openai/src/config.rs b/backend/crates/providers/openai/src/config.rs
index 5e9b83d40..3bf56df7b 100644
--- a/backend/crates/providers/openai/src/config.rs
+++ b/backend/crates/providers/openai/src/config.rs
@@ -68,11 +68,6 @@ impl OpenAiConfig {
         self.quota.refresh_policy()
     }
 
-    #[must_use]
-    pub const fn quota_skip_exhausted(&self) -> bool {
-        self.quota.skip_exhausted
-    }
-
     #[must_use]
     pub fn token_client_config(&self) -> TokenClientConfig {
         TokenClientConfig {
@@ -209,14 +204,12 @@ impl CodexWebSocketPoolSettings {
 #[serde(deny_unknown_fields)]
 pub struct CodexQuotaSettings {
     pub refresh_interval_minutes: u64,
-    pub skip_exhausted: bool,
 }
 
 impl Default for CodexQuotaSettings {
     fn default() -> Self {
         Self {
             refresh_interval_minutes: 15,
-            skip_exhausted: true,
         }
     }
 }
diff --git a/backend/crates/providers/openai/src/credential/admin.rs b/backend/crates/providers/openai/src/credential/admin.rs
index 70f5cf36e..13a1b5b91 100644
--- a/backend/crates/providers/openai/src/credential/admin.rs
+++ b/backend/crates/providers/openai/src/credential/admin.rs
@@ -10,9 +10,9 @@ use std::time::SystemTime;
 
 use chrono::{DateTime, FixedOffset, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialCasUpdate, CredentialRevision, LoadedCredential,
+    AccountErrorReason, CredentialCasUpdate, CredentialRevision, CredentialState, LoadedCredential,
     NewProviderAccount, ProviderAccount, ProviderAccountId, ProviderAccountIdentity,
-    ProviderAccountUpdate,
+    ProviderAccountUpdate, QuotaEvidence, QuotaState,
 };
 use gateway_core::provider_ports::{
     ProviderLeaseAcquisition, ProviderLeaseGuard, ProviderLeasePort, ProviderLeaseRequest,
@@ -433,7 +433,13 @@ impl CodexCredentialAdmin {
             Some(input.verified_account.chatgpt_account_id),
             input.verified_account.plan_type,
         )
-        .with_runtime_state(input.enabled, AccountAvailability::Ready)
+        .with_account_facts(
+            input.enabled,
+            CredentialState::Ready,
+            QuotaState::unknown(),
+            None,
+            None,
+        )
         .with_refresh_schedule(
             input.secret.refresh_token.is_some(),
             optional_time(input.next_refresh_at),
@@ -479,13 +485,16 @@ impl CodexCredentialAdmin {
             optional_time(input.access_token_expires_at),
         )
         .with_profile(email, upstream_account_id, plan_type)
-        .with_runtime_state(
+        .with_account_facts(
             input.enabled,
             if has_upstream_user_id {
-                AccountAvailability::Ready
+                CredentialState::Ready
             } else {
-                AccountAvailability::Unknown
+                CredentialState::Unknown
             },
+            QuotaState::unknown(),
+            (!has_upstream_user_id).then_some(AccountErrorReason::AccountUnverified),
+            None,
         )
         .with_refresh_schedule(
             input.secret.refresh_token.is_some(),
@@ -898,10 +907,10 @@ impl CodexCredentialAdminService {
                     if !account_ids.insert(account_id.clone()) {
                         return Err(CodexCredentialAdminError::InvalidInput);
                     }
-                    let (enabled, availability) =
-                        import_runtime_state(candidate.status.as_deref())?;
+                    let facts =
+                        parse_cpr_account_facts(candidate.status.as_deref(), SystemTime::now())?;
                     let mut account =
-                        self.prepare_agent_identity_import(&candidate, account_id, enabled)?;
+                        self.prepare_agent_identity_import(&candidate, account_id, facts.enabled)?;
                     let upstream_user_id = account
                         .account
                         .upstream_user_id()
@@ -915,7 +924,7 @@ impl CodexCredentialAdminService {
                     if !upstream_identities.insert((upstream_user_id, upstream_account_id)) {
                         return Err(CodexCredentialAdminError::InvalidInput);
                     }
-                    account.account = account.account.with_runtime_state(enabled, availability);
+                    account.account = facts.apply(account.account);
                     account
                 }
             };
@@ -1048,7 +1057,13 @@ impl CodexCredentialAdminService {
             Some(upstream_account_id),
             candidate.plan_type.clone(),
         )
-        .with_runtime_state(enabled, AccountAvailability::Ready)
+        .with_account_facts(
+            enabled,
+            CredentialState::Ready,
+            QuotaState::unknown(),
+            None,
+            None,
+        )
         .with_refresh_schedule(false, None);
         Ok(NewProviderAccount {
             account,
@@ -1065,11 +1080,13 @@ fn cpr_status(account: &ProviderAccount) -> &'static str {
     if !account.enabled() {
         return "disabled";
     }
-    match account.availability() {
-        AccountAvailability::QuotaExhausted => "quota_exhausted",
-        AccountAvailability::Expired | AccountAvailability::Invalid => "expired",
-        AccountAvailability::Banned => "banned",
-        AccountAvailability::Unknown | AccountAvailability::Ready => "active",
+    if account.quota().is_exhausted() {
+        return "quota_exhausted";
+    }
+    match account.credential_state() {
+        CredentialState::Expired | CredentialState::Invalid => "expired",
+        CredentialState::Banned => "banned",
+        CredentialState::Unknown | CredentialState::Ready => "active",
     }
 }
 
@@ -1292,20 +1309,65 @@ fn normalize_import_text(value: &str, max_bytes: usize) -> Option<String> {
         .then(|| value.to_owned())
 }
 
-fn import_runtime_state(
+struct ImportedCprAccountFacts {
+    enabled: bool,
+    credential_state: CredentialState,
+    quota: QuotaState,
+    error_reason: Option<AccountErrorReason>,
+}
+
+impl ImportedCprAccountFacts {
+    fn apply(self, account: ProviderAccount) -> ProviderAccount {
+        account.with_account_facts(
+            self.enabled,
+            self.credential_state,
+            self.quota,
+            self.error_reason,
+            None,
+        )
+    }
+}
+
+fn parse_cpr_account_facts(
     status: Option<&str>,
-) -> Result<(bool, AccountAvailability), CodexCredentialAdminError> {
+    observed_at: SystemTime,
+) -> Result<ImportedCprAccountFacts, CodexCredentialAdminError> {
     match status
         .map(str::trim)
         .unwrap_or("active")
         .to_ascii_lowercase()
         .as_str()
     {
-        "active" => Ok((true, AccountAvailability::Ready)),
-        "disabled" => Ok((false, AccountAvailability::Ready)),
-        "expired" => Ok((true, AccountAvailability::Expired)),
-        "quota_exhausted" => Ok((true, AccountAvailability::QuotaExhausted)),
-        "banned" => Ok((true, AccountAvailability::Banned)),
+        "active" => Ok(ImportedCprAccountFacts {
+            enabled: true,
+            credential_state: CredentialState::Ready,
+            quota: QuotaState::unknown(),
+            error_reason: None,
+        }),
+        "disabled" => Ok(ImportedCprAccountFacts {
+            enabled: false,
+            credential_state: CredentialState::Ready,
+            quota: QuotaState::unknown(),
+            error_reason: None,
+        }),
+        "expired" => Ok(ImportedCprAccountFacts {
+            enabled: true,
+            credential_state: CredentialState::Expired,
+            quota: QuotaState::unknown(),
+            error_reason: Some(AccountErrorReason::CredentialExpired),
+        }),
+        "quota_exhausted" => Ok(ImportedCprAccountFacts {
+            enabled: true,
+            credential_state: CredentialState::Ready,
+            quota: QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
+            error_reason: None,
+        }),
+        "banned" => Ok(ImportedCprAccountFacts {
+            enabled: true,
+            credential_state: CredentialState::Banned,
+            quota: QuotaState::unknown(),
+            error_reason: Some(AccountErrorReason::AccountBanned),
+        }),
         _ => Err(CodexCredentialAdminError::InvalidInput),
     }
 }
diff --git a/backend/crates/providers/openai/src/credential/catalog.rs b/backend/crates/providers/openai/src/credential/catalog.rs
index 5dd4825fc..6418cb879 100644
--- a/backend/crates/providers/openai/src/credential/catalog.rs
+++ b/backend/crates/providers/openai/src/credential/catalog.rs
@@ -7,7 +7,7 @@ use std::time::{Duration, SystemTime};
 
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, OpaqueProviderData, ProviderAccount, ProviderAccountId,
+    CredentialState, OpaqueProviderData, ProviderAccount, ProviderAccountId,
 };
 use gateway_core::engine::provider::ProviderCatalogGeneration;
 use gateway_core::provider_ports::{
@@ -780,12 +780,8 @@ fn eligible_catalog_account(account: &ProviderAccount, now: SystemTime) -> bool
         && account
             .access_token_expires_at()
             .is_none_or(|expires_at| expires_at > now)
-        && match account.availability() {
-            AccountAvailability::Unknown
-            | AccountAvailability::Ready
-            | AccountAvailability::QuotaExhausted => true,
-            AccountAvailability::Expired
-            | AccountAvailability::Banned
-            | AccountAvailability::Invalid => false,
-        }
+        && matches!(
+            account.credential_state(),
+            CredentialState::Unknown | CredentialState::Ready
+        )
 }
diff --git a/backend/crates/providers/openai/src/credential/quota/evidence.rs b/backend/crates/providers/openai/src/credential/quota/evidence.rs
new file mode 100644
index 000000000..3f374359f
--- /dev/null
+++ b/backend/crates/providers/openai/src/credential/quota/evidence.rs
@@ -0,0 +1,46 @@
+//! 额度接口失败到规范化账号事实的唯一分类边界。
+
+use gateway_core::engine::credential::{AccountErrorReason, CredentialState, QuotaEvidence};
+use reqwest::StatusCode;
+use serde_json::Value;
+
+use crate::transport::CodexClientError;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum QuotaEndpointFailure {
+    Credential {
+        state: CredentialState,
+        reason: AccountErrorReason,
+    },
+    Exhausted(QuotaEvidence),
+}
+
+/// 额度 endpoint 只有明确 402 能改变账号事实。401/403、429、5xx 与传输失败
+/// 均不足以判断凭据或账号状态，留给 OAuth 与真实推理请求确认。
+pub(crate) fn classify_quota_endpoint_failure(
+    error: &CodexClientError,
+) -> Option<QuotaEndpointFailure> {
+    let CodexClientError::Upstream { status, body, .. } = error else {
+        return None;
+    };
+    if *status != StatusCode::PAYMENT_REQUIRED {
+        return None;
+    }
+    if is_deactivated_workspace(body) {
+        return Some(QuotaEndpointFailure::Credential {
+            state: CredentialState::Banned,
+            reason: AccountErrorReason::AccountBanned,
+        });
+    }
+    Some(QuotaEndpointFailure::Exhausted(
+        QuotaEvidence::PaymentRequired,
+    ))
+}
+
+fn is_deactivated_workspace(body: &str) -> bool {
+    serde_json::from_str::<Value>(body)
+        .ok()
+        .is_some_and(|value| {
+            value.pointer("/detail/code").and_then(Value::as_str) == Some("deactivated_workspace")
+        })
+}
diff --git a/backend/crates/providers/openai/src/credential/quota/mod.rs b/backend/crates/providers/openai/src/credential/quota/mod.rs
index bac8a6c0d..4c9cfd964 100644
--- a/backend/crates/providers/openai/src/credential/quota/mod.rs
+++ b/backend/crates/providers/openai/src/credential/quota/mod.rs
@@ -1,9 +1,9 @@
-//! Codex quota 服务编排：请求级额度投影、被动/主动同步与 429 合成。
+//! Codex quota 服务编排：权威额度事实、展示投影、主动/被动同步与 429 冷却。
 //!
 //! - [`snapshot`]：快照/窗口解析、聚合、O(1) 滚动与调度信号。
-//! - [`recovery`]：402 恢复证据与 availability 转换。
+//! - [`evidence`]：额度接口错误到凭据/额度事实的分类。
 
-pub(crate) mod recovery;
+pub(crate) mod evidence;
 pub(crate) mod snapshot;
 
 pub use snapshot::{
@@ -13,12 +13,14 @@ pub use snapshot::{
 
 use std::collections::{BTreeMap, BTreeSet};
 use std::sync::{Arc, RwLock};
-use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+use std::time::{Duration, Instant, SystemTime};
 
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountQuotaSignals, CredentialRevision, OpaqueProviderData,
-    ProviderAccount, ProviderAccountId, ProviderAccountStore, QuotaObservation, QuotaWriteOutcome,
+    AccountErrorReason, AccountQuotaSignals, CredentialRevision, CredentialState,
+    OpaqueProviderData, ProviderAccount, ProviderAccountId, ProviderAccountStore,
+    QuotaAccessChange, QuotaAccessState, QuotaEvidence, QuotaObservation, QuotaState,
+    QuotaWriteOutcome,
 };
 use gateway_core::provider_ports::{ProviderCooldown, ProviderCooldownPort};
 use gateway_protocol::openai::events::{
@@ -36,10 +38,7 @@ use crate::transport::{CodexBackendClient, CodexClientError, CodexRequestContext
 
 use super::agent_identity::{CodexAgentIdentityTaskService, PreparedCodexRuntimeCredential};
 use super::repository::{CodexCredentialRepository, CredentialRepositoryError};
-use recovery::{
-    authoritative_quota_snapshot_state, quota_state_reason, quota_state_transition,
-    quota_success_state,
-};
+use evidence::{QuotaEndpointFailure, classify_quota_endpoint_failure};
 use snapshot::{
     parse_account_quota_snapshot, quota_projection_ttl, quota_snapshot_from_observation,
     scheduling_signals_from_snapshot,
@@ -48,7 +47,8 @@ use snapshot::{
 const DEFAULT_RATE_LIMIT_COOLDOWN: Duration = Duration::from_secs(60);
 pub(crate) const QUOTA_SCHEDULING_TTL: Duration = Duration::from_secs(10 * 60);
 const QUOTA_HYDRATION_FAILURE_TTL: Duration = Duration::from_secs(5);
-const QUOTA_PERIODIC_REFRESH_MIN_INTERVAL: Duration = Duration::from_secs(30 * 60);
+const EXHAUSTED_QUOTA_FALLBACK_RECHECK_INTERVAL: Duration = Duration::from_secs(30 * 60);
+const EXHAUSTED_QUOTA_REFRESH_RETRY_INTERVAL: Duration = Duration::from_secs(30 * 60);
 /// 首次 OAuth 异步观察失败时，由既有 quota worker 兜底重试的单轮上限。
 const INITIAL_QUOTA_SYNC_BATCH: usize = 100;
 // 5xx 上游拒绝的短退避重试预算；指数退避 1s/2s，吞掉瞬时抖动。
@@ -130,6 +130,12 @@ pub struct CodexCredentialQuotaService {
     scheduling: CodexQuotaSchedulingProjection,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum QuotaRefreshAuthority {
+    ObserveAccess,
+    PreserveAccess,
+}
+
 #[derive(Clone, Default)]
 struct CodexQuotaSchedulingProjection {
     state: Arc<RwLock<CodexQuotaProjectionState>>,
@@ -299,12 +305,7 @@ impl CodexQuotaSchedulingProjection {
     ) -> Vec<ProviderAccount> {
         let candidates = accounts
             .into_iter()
-            .filter_map(|account| {
-                let limit_reached = self
-                    .signals(&account)
-                    .is_some_and(|signals| signals.limit_reached());
-                quota_refresh_candidate(account, now, limit_reached)
-            })
+            .filter_map(|account| quota_refresh_candidate(account, now))
             .collect::<Vec<_>>();
         let candidate_ids = candidates
             .iter()
@@ -319,8 +320,8 @@ impl CodexQuotaSchedulingProjection {
             .last_periodic_refresh_at
             .retain(|account_id, _| candidate_ids.contains(account_id));
 
-        // 正常账号只由真实请求的响应头和 `codex.rate_limits` 被动同步。定时器只兜底
-        // 已耗尽账号，且不依据 reset 时间跳过复核；每个账号仍至少间隔 30 分钟。
+        // 正常账号只由真实请求的响应头和 `codex.rate_limits` 被动同步。定时器只复核
+        // 已耗尽且已到 reset/fallback 时刻的账号；重复复核至少间隔 30 分钟。
         let mut reserved = Vec::new();
         for account in candidates {
             if !periodic_quota_refresh_due(&state, account.id(), refreshed_at) {
@@ -335,16 +336,13 @@ impl CodexQuotaSchedulingProjection {
     }
 }
 
-fn quota_refresh_candidate(
-    account: ProviderAccount,
-    now: SystemTime,
-    limit_reached: bool,
-) -> Option<ProviderAccount> {
-    // 定时器只兜底已耗尽或任一窗口触顶的账号；
-    // 正常账号由真实请求的响应头被动同步。
+fn quota_refresh_candidate(account: ProviderAccount, now: SystemTime) -> Option<ProviderAccount> {
+    // reset 到期是“应刷新”的信号，不是“已恢复”的证据。
     (eligible_periodic_quota_refresh(&account, now)
-        && (account.availability() == AccountAvailability::QuotaExhausted || limit_reached))
-        .then_some(account)
+        && account
+            .quota()
+            .exhaustion_refresh_due(now, EXHAUSTED_QUOTA_FALLBACK_RECHECK_INTERVAL))
+    .then_some(account)
 }
 
 fn periodic_quota_refresh_due(
@@ -356,7 +354,7 @@ fn periodic_quota_refresh_due(
         .last_periodic_refresh_at
         .get(account_id)
         .is_none_or(|last| {
-            now.saturating_duration_since(*last) >= QUOTA_PERIODIC_REFRESH_MIN_INTERVAL
+            now.saturating_duration_since(*last) >= EXHAUSTED_QUOTA_REFRESH_RETRY_INTERVAL
         })
 }
 
@@ -400,70 +398,55 @@ impl CodexCredentialQuotaService {
         }
     }
 
-    /// 写入新快照前读取 core primary 已确认耗尽窗口的 reset，用于判断该窗口是否真的推进。
-    async fn previous_confirmed_reset(&self, account: &ProviderAccount) -> Option<SystemTime> {
-        let observations = self
-            .store
-            .get_quotas(std::slice::from_ref(account.id()))
-            .await
-            .ok()?;
-        let observation = observations.into_iter().find(|observation| {
-            observation.account_id == *account.id()
-                && observation.expected_revision == account.revision()
-        })?;
-        let snapshot = quota_snapshot_from_observation(&observation)?;
-        snapshot
-            .core_primary_window()
-            .and_then(|window| window.reset_at())
-            .map(SystemTime::from)
-    }
-
-    /// 将已确认的额度拒绝投影为 100%，使展示、调度和恢复共用同一窗口事实。
-    ///
-    /// `reset_at` 来自官方 `usage_limit_reached` 错误体；缺失时保留当前快照的 reset。
+    /// 真实推理错误只更新额度访问事实，不伪造 Provider JSON 或展示百分比。
     pub(crate) async fn record_confirmed_exhaustion(
         &self,
         account: &ProviderAccount,
-        reset_at: Option<i64>,
+        evidence: QuotaEvidence,
+        reset_at: Option<SystemTime>,
+        observed_at: SystemTime,
     ) -> Result<(), CodexCredentialQuotaError> {
-        let existing = self
-            .store
-            .get_quotas(std::slice::from_ref(account.id()))
-            .await?
-            .into_iter()
-            .find(|observation| {
-                observation.account_id == *account.id()
-                    && observation.expected_revision == account.revision()
-            })
-            .and_then(|observation| observation.quota)
-            .map(OpaqueProviderData::into_inner)
-            .unwrap_or_default();
-        let quota = confirmed_exhaustion_projection(
-            normalize_quota_window_placeholders(existing),
-            reset_at,
-        );
-        let observed_at = SystemTime::now();
         let outcome = self
             .store
-            .compare_and_swap_quota(QuotaObservation {
+            .apply_quota_access(QuotaAccessChange {
                 account_id: account.id().clone(),
                 expected_revision: account.revision(),
-                quota: Some(OpaqueProviderData::new(quota.clone())),
-                observed_at: Some(observed_at),
-                limit_reached: Some(true),
+                state: QuotaState::exhausted(evidence, observed_at, reset_at),
             })
             .await?;
         if outcome == QuotaWriteOutcome::Conflict {
             return Err(CodexCredentialQuotaError::RevisionConflict);
         }
-        if let Ok(snapshot) = parse_account_quota_snapshot(
-            account.id().clone(),
-            account.revision(),
-            observed_at,
-            &Value::Object(quota),
-        ) {
-            self.scheduling.observe(&snapshot);
+        Ok(())
+    }
+
+    /// 成功推理是额度可访问的权威证据，同时解除账号级 429 冷却。
+    pub(crate) async fn record_successful_inference(
+        &self,
+        account: &ProviderAccount,
+        observed_at: SystemTime,
+    ) -> Result<(), CodexCredentialQuotaError> {
+        // 已经发出的并发请求可能晚于耗尽事实成功返回；真实成功仍是独立的
+        // Allowed 权威证据，但调度不会为了试探恢复而放行耗尽账号。
+        if account.quota().access() == QuotaAccessState::Exhausted {
+            let outcome = self
+                .store
+                .apply_quota_access(QuotaAccessChange {
+                    account_id: account.id().clone(),
+                    expected_revision: account.revision(),
+                    state: QuotaState::allowed(observed_at),
+                })
+                .await?;
+            if outcome == QuotaWriteOutcome::Conflict {
+                return Err(CodexCredentialQuotaError::RevisionConflict);
+            }
         }
+        self.cooldowns
+            .clear(account.id(), account.revision())
+            .await
+            .map_err(|error| CodexCredentialQuotaError::Store {
+                detail: error.to_string(),
+            })?;
         Ok(())
     }
 
@@ -562,30 +545,27 @@ impl CodexCredentialQuotaService {
                     );
                 }
                 Err(CodexQuotaFetchError::Upstream { account, error }) => {
-                    match quota_state_transition(&error) {
-                        // 402：真额度耗尽，写入 QuotaExhausted（worker 按 reset_at 自动恢复）。
-                        Some(AccountAvailability::QuotaExhausted) => {
+                    match classify_quota_endpoint_failure(&error) {
+                        Some(QuotaEndpointFailure::Exhausted(evidence)) => {
                             summary.exhausted += 1;
-                            self.persist_upstream_state(
-                                &account,
-                                AccountAvailability::QuotaExhausted,
-                                &error,
-                                observed_at,
-                            )
-                            .await;
+                            if let Err(write_error) = self
+                                .record_confirmed_exhaustion(&account, evidence, None, observed_at)
+                                .await
+                            {
+                                summary.transient += 1;
+                                tracing::warn!(
+                                    account_id = %account.id(),
+                                    error = %write_error,
+                                    "OpenAI quota exhaustion fact write failed"
+                                );
+                            }
                         }
-                        Some(AccountAvailability::Banned) => {
+                        Some(QuotaEndpointFailure::Credential { state, reason }) => {
                             summary.banned += 1;
-                            self.persist_upstream_state(
-                                &account,
-                                AccountAvailability::Banned,
-                                &error,
-                                observed_at,
-                            )
-                            .await;
+                            self.persist_credential_failure(&account, state, reason, observed_at)
+                                .await;
                         }
-                        // usage 401/403 与 429/503 都不写 availability；前者等待 OAuth 或真实请求确认。
-                        None | Some(_) => {
+                        None => {
                             summary.transient += 1;
                             tracing::warn!(
                                 account_id = %account.id(),
@@ -613,7 +593,7 @@ impl CodexCredentialQuotaService {
         let observed = self.store.get_quotas(&account_ids).await?;
         let observed_ids = observed
             .into_iter()
-            .filter_map(|observation| observation.observed_at.map(|_| observation.account_id))
+            .map(|observation| observation.account_id)
             .collect::<BTreeSet<_>>();
         Ok(accounts
             .iter()
@@ -633,79 +613,40 @@ impl CodexCredentialQuotaService {
         observed_at: SystemTime,
         summary: &mut CodexQuotaSyncSummary,
     ) -> Result<(), CodexCredentialQuotaError> {
-        let refreshed_snapshot = parse_account_quota_snapshot(
-            account.id().clone(),
-            account.revision(),
-            observed_at,
-            value,
-        )?;
-        let previous_reset_at = self.previous_confirmed_reset(account).await;
         let object = normalize_quota_window_placeholders(
             value
                 .as_object()
                 .cloned()
                 .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?,
         );
-        let object = if account.availability() == AccountAvailability::QuotaExhausted
-            && quota_success_state(
-                account.availability(),
-                &refreshed_snapshot,
-                previous_reset_at,
-            )
-            .is_none()
-        {
-            confirmed_exhaustion_projection(
-                object,
-                confirmed_exhaustion_reset_at(previous_reset_at, &refreshed_snapshot),
-            )
-        } else {
-            object
-        };
         let snapshot = parse_account_quota_snapshot(
             account.id().clone(),
             account.revision(),
             observed_at,
             &Value::Object(object.clone()),
         )?;
-        let fact = snapshot.fact();
+        let state = account.quota().merge_observation(snapshot.quota());
+        let snapshot = snapshot.with_quota_state(state);
         let outcome = self
             .store
             .compare_and_swap_quota(QuotaObservation {
                 account_id: account.id().clone(),
                 expected_revision: account.revision(),
-                quota: Some(OpaqueProviderData::new(object)),
-                observed_at: Some(observed_at),
-                limit_reached: Some(fact.exhausted()),
+                quota: OpaqueProviderData::new(object),
+                observed_at,
+                state,
             })
             .await?;
         if outcome == QuotaWriteOutcome::Conflict {
             summary.stale += 1;
             return Ok(());
         }
-        let Some(current) = self.store.get_account(account.id()).await? else {
-            summary.stale += 1;
-            return Ok(());
-        };
-        if current.revision() != account.revision() {
-            summary.stale += 1;
-            return Ok(());
-        }
         self.scheduling.observe(&snapshot);
-        if fact.exhausted() {
+        if snapshot.quota().is_exhausted() {
             summary.exhausted += 1;
         } else {
             summary.updated += 1;
         }
-        if let Some(availability) = authoritative_quota_snapshot_state(
-            current.availability(),
-            &refreshed_snapshot,
-            previous_reset_at,
-        ) {
-            let _ = self
-                .repository
-                .apply_state(&current, availability, observed_at)
-                .await;
-        }
         Ok(())
     }
 
@@ -722,11 +663,6 @@ impl CodexCredentialQuotaService {
             .limits
             .values()
             .any(|details| passive_rate_limit_snapshot(details).is_some());
-        let previous_reset_at = if account.availability() == AccountAvailability::QuotaExhausted {
-            self.previous_confirmed_reset(account).await
-        } else {
-            None
-        };
         let existing = self
             .store
             .get_quotas(std::slice::from_ref(account.id()))
@@ -736,17 +672,14 @@ impl CodexCredentialQuotaService {
                 observation.account_id == *account.id()
                     && observation.expected_revision == account.revision()
             });
-        let existing_observed_at = existing
-            .as_ref()
-            .and_then(|observation| observation.observed_at);
+        let existing_state = existing.as_ref().map(|observation| observation.state);
         let existing = existing
-            .and_then(|observation| observation.quota)
-            .map(OpaqueProviderData::into_inner)
+            .map(|observation| observation.quota.into_inner())
             .unwrap_or_default();
         // 套餐、credits 等元数据可以更新，但没有额度窗口事实时必须保留旧观察时刻，
         // 也不能借旧快照重新推导 quota state。
         if !has_quota_facts {
-            let Some(observed_at) = existing_observed_at else {
+            let Some(state) = existing_state else {
                 return Ok(false);
             };
             let outcome = self
@@ -754,62 +687,42 @@ impl CodexCredentialQuotaService {
                 .compare_and_swap_quota(QuotaObservation {
                     account_id: account.id().clone(),
                     expected_revision: account.revision(),
-                    quota: Some(OpaqueProviderData::new(merge_passive_quota(
-                        existing,
-                        &rate_limits,
-                    ))),
-                    observed_at: Some(observed_at),
-                    limit_reached: None,
+                    quota: OpaqueProviderData::new(merge_passive_quota(existing, &rate_limits)),
+                    observed_at: SystemTime::now(),
+                    state,
                 })
                 .await?;
             return Ok(outcome != QuotaWriteOutcome::Conflict);
         }
         let quota = merge_passive_quota(existing, &rate_limits);
         let observed_at = SystemTime::now();
-        let refreshed_snapshot = parse_account_quota_snapshot(
-            account.id().clone(),
-            account.revision(),
-            observed_at,
-            &Value::Object(quota.clone()),
-        )?;
-        let quota = if account.availability() == AccountAvailability::QuotaExhausted {
-            // 被动成功响应不能解除确认额度耗尽；继续展示 100%，直到权威 usage 快照
-            // 证明旧 reset 已跨过且新窗口已经推进。
-            confirmed_exhaustion_projection(
-                quota,
-                confirmed_exhaustion_reset_at(previous_reset_at, &refreshed_snapshot),
-            )
-        } else {
-            quota
-        };
-        let fact = parse_codex_quota_usage(&Value::Object(quota.clone()))?;
         let snapshot = parse_account_quota_snapshot(
             account.id().clone(),
             account.revision(),
             observed_at,
             &Value::Object(quota.clone()),
-        );
+        )?;
+        // 这些 headers 来自一次成功推理，访问结论优先于可能滞后的百分比。
+        let state = QuotaState::allowed(observed_at);
         let outcome = self
             .store
             .compare_and_swap_quota(QuotaObservation {
                 account_id: account.id().clone(),
                 expected_revision: account.revision(),
-                quota: Some(OpaqueProviderData::new(quota)),
-                observed_at: Some(observed_at),
-                limit_reached: Some(fact.exhausted()),
+                quota: OpaqueProviderData::new(quota),
+                observed_at,
+                state,
             })
             .await?;
         if outcome == QuotaWriteOutcome::Conflict {
             return Ok(false);
         }
-        if let Ok(snapshot) = snapshot {
-            self.scheduling.observe(&snapshot);
-        }
+        self.scheduling.observe(&snapshot);
         Ok(true)
     }
 
     /// 真实 429 的单一事实入口：写入 Redis 临时限流冷却（`until = now + retry_after`）。
-    /// availability 与 quota 主窗口（额度重置时间）都不改变——临时限流是独立维度，
+    /// 凭据与额度主窗口（额度重置时间）都不改变——临时限流是独立维度，
     /// 到期由 Redis key 过期自动解除，不污染配额耗尽状态。
     /// 已有更晚的冷却不会被缩短（put_if_later）。
     pub async fn apply_rate_limit_429(
@@ -838,7 +751,6 @@ impl CodexCredentialQuotaService {
     pub async fn rate_limited_until(
         &self,
         account_id: &ProviderAccountId,
-        credential_revision: CredentialRevision,
     ) -> Result<Option<SystemTime>, CodexCredentialQuotaError> {
         let Some(cooldown) = self.cooldowns.read(account_id).await.map_err(|error| {
             CodexCredentialQuotaError::Store {
@@ -848,9 +760,6 @@ impl CodexCredentialQuotaService {
         else {
             return Ok(None);
         };
-        if cooldown.credential_revision() != credential_revision {
-            return Ok(None);
-        }
         let until = cooldown.until();
         if until <= SystemTime::now() {
             return Ok(None);
@@ -894,18 +803,17 @@ impl CodexCredentialQuotaService {
         {
             return Err(CodexCredentialQuotaError::RevisionConflict);
         }
-        let Some(data) = observation.quota else {
+        if observation.quota.expose_to_provider().is_empty() {
             return Ok(None);
-        };
-        let observed_at = observation
-            .observed_at
-            .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
+        }
+        let observed_at = observation.observed_at;
         let snapshot = parse_account_quota_snapshot(
             account_id.clone(),
             account.revision(),
             observed_at,
-            &Value::Object(data.expose_to_provider().clone()),
-        )?;
+            &Value::Object(observation.quota.expose_to_provider().clone()),
+        )?
+        .with_quota_state(observation.state);
         self.scheduling.observe(&snapshot);
         Ok(Some(snapshot))
     }
@@ -915,7 +823,8 @@ impl CodexCredentialQuotaService {
         &self,
         account_id: &ProviderAccountId,
     ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
-        self.refresh_account_snapshot(account_id).await
+        self.refresh_account_snapshot(account_id, QuotaRefreshAuthority::ObserveAccess)
+            .await
     }
 
     /// 真实限额失败后的异步刷新只补齐展示快照，不允许 usage 快照撤销已确认的失败状态。
@@ -923,12 +832,14 @@ impl CodexCredentialQuotaService {
         &self,
         account_id: &ProviderAccountId,
     ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
-        self.refresh_account_snapshot(account_id).await
+        self.refresh_account_snapshot(account_id, QuotaRefreshAuthority::PreserveAccess)
+            .await
     }
 
     async fn refresh_account_snapshot(
         &self,
         account_id: &ProviderAccountId,
+        authority: QuotaRefreshAuthority,
     ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
         let account = self
             .store
@@ -957,104 +868,77 @@ impl CodexCredentialQuotaService {
                     });
                 }
                 Err(CodexQuotaFetchError::Upstream { account, error }) => {
-                    // 402 与明确的停用错误写对应状态；usage 401/403 不写 availability。
-                    if let Some(availability) = quota_state_transition(&error) {
-                        self.persist_upstream_state(&account, availability, &error, observed_at)
-                            .await;
+                    match classify_quota_endpoint_failure(&error) {
+                        Some(QuotaEndpointFailure::Exhausted(evidence)) => {
+                            self.record_confirmed_exhaustion(&account, evidence, None, observed_at)
+                                .await?;
+                        }
+                        Some(QuotaEndpointFailure::Credential { state, reason }) => {
+                            self.persist_credential_failure(&account, state, reason, observed_at)
+                                .await;
+                        }
+                        None => {}
                     }
                     return Err(CodexCredentialQuotaError::Upstream {
                         detail: error.to_string(),
                     });
                 }
             };
-        let refreshed_snapshot = parse_account_quota_snapshot(
-            account.id().clone(),
-            account.revision(),
-            observed_at,
-            &value,
-        )?;
-        let previous_reset_at = self.previous_confirmed_reset(&account).await;
         let object = normalize_quota_window_placeholders(
             value
                 .as_object()
                 .cloned()
                 .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?,
         );
-        let object = if account.availability() == AccountAvailability::QuotaExhausted
-            && quota_success_state(
-                account.availability(),
-                &refreshed_snapshot,
-                previous_reset_at,
-            )
-            .is_none()
-        {
-            confirmed_exhaustion_projection(
-                object,
-                confirmed_exhaustion_reset_at(previous_reset_at, &refreshed_snapshot),
-            )
-        } else {
-            object
-        };
         let snapshot = parse_account_quota_snapshot(
             account.id().clone(),
             account.revision(),
             observed_at,
             &Value::Object(object.clone()),
         )?;
+        let state = match authority {
+            QuotaRefreshAuthority::ObserveAccess => {
+                account.quota().merge_observation(snapshot.quota())
+            }
+            QuotaRefreshAuthority::PreserveAccess => account.quota(),
+        };
+        let snapshot = snapshot.with_quota_state(state);
         if self
             .store
             .compare_and_swap_quota(QuotaObservation {
                 account_id: account.id().clone(),
                 expected_revision: account.revision(),
-                quota: Some(OpaqueProviderData::new(object)),
-                observed_at: Some(observed_at),
-                limit_reached: Some(snapshot.fact().exhausted()),
+                quota: OpaqueProviderData::new(object),
+                observed_at,
+                state,
             })
             .await?
             == QuotaWriteOutcome::Conflict
         {
             return Err(CodexCredentialQuotaError::RevisionConflict);
         }
-        let current = self
-            .store
-            .get_account(account.id())
-            .await?
-            .ok_or(CodexCredentialQuotaError::NotFound)?;
-        if current.revision() != account.revision() {
-            return Err(CodexCredentialQuotaError::RevisionConflict);
-        }
         self.scheduling.observe(&snapshot);
-        if let Some(availability) = authoritative_quota_snapshot_state(
-            current.availability(),
-            &refreshed_snapshot,
-            previous_reset_at,
-        ) {
-            self.repository
-                .apply_state(&current, availability, observed_at)
-                .await?;
-        }
         Ok(snapshot)
     }
 
-    async fn persist_upstream_state(
+    async fn persist_credential_failure(
         &self,
         account: &ProviderAccount,
-        availability: AccountAvailability,
-        upstream_error: &CodexClientError,
+        credential_state: CredentialState,
+        reason: AccountErrorReason,
         observed_at: SystemTime,
     ) {
-        let reason = quota_state_reason(upstream_error).map(str::to_owned);
         if let Err(error) = self
             .repository
-            .apply_state_with_message(account, availability, observed_at, reason.clone())
+            .apply_state_with_reason(account, credential_state, observed_at, Some(reason), None)
             .await
         {
             tracing::warn!(
                 account_id = %account.id(),
-                ?availability,
-                reason = reason.as_deref().unwrap_or_default(),
+                ?credential_state,
+                reason = reason.as_str(),
                 error = %error,
-                "OpenAI quota upstream state write failed"
+                "OpenAI quota credential fact write failed"
             );
         }
     }
@@ -1163,10 +1047,8 @@ fn eligible_periodic_quota_refresh(account: &ProviderAccount, now: SystemTime) -
 fn eligible_initial_quota_sync(account: &ProviderAccount, now: SystemTime) -> bool {
     // 首次观察只兜底刚入库、尚无 quota 快照的账号。已耗尽等运行时状态必须由
     // periodic 路径处理，才能保留同一账号的最小复核间隔。
-    matches!(
-        account.availability(),
-        AccountAvailability::Ready | AccountAvailability::Unknown
-    ) && eligible_periodic_quota_refresh(account, now)
+    account.credential_state() == CredentialState::Ready
+        && eligible_periodic_quota_refresh(account, now)
 }
 
 fn access_token_is_current(account: &ProviderAccount, now: SystemTime) -> bool {
@@ -1297,71 +1179,6 @@ fn secondary_window_is_placeholder(window: &Map<String, Value>) -> bool {
     })
 }
 
-/// 用已确认的上游额度拒绝覆盖 core 限额投影。
-///
-/// 上游 usage 快照可能在结算期间短暂滞后为 98/99% 或 `allowed=true`；保留其他
-/// 原始 metadata，但把 core 窗口固定为 100%，直到权威快照证明进入下一窗口。
-fn confirmed_exhaustion_projection(
-    mut quota: Map<String, Value>,
-    reset_at: Option<i64>,
-) -> Map<String, Value> {
-    let mut rate_limit = quota
-        .remove("rate_limit")
-        .and_then(|value| value.as_object().cloned())
-        .unwrap_or_default();
-    rate_limit.insert("allowed".to_owned(), Value::Bool(false));
-    rate_limit.insert("limit_reached".to_owned(), Value::Bool(true));
-    for field in ["primary_window", "secondary_window"] {
-        let existed = rate_limit.contains_key(field);
-        let mut window = rate_limit
-            .remove(field)
-            .and_then(|value| value.as_object().cloned())
-            .unwrap_or_default();
-        if field == "primary_window" || existed {
-            window.insert("used_percent".to_owned(), Value::from(100_u64));
-            if field == "primary_window"
-                && let Some(reset_at) = reset_at
-            {
-                window.insert("reset_at".to_owned(), Value::from(reset_at));
-            }
-            rate_limit.insert(field.to_owned(), Value::Object(window));
-        }
-    }
-    quota.insert("rate_limit".to_owned(), Value::Object(rate_limit));
-    quota
-}
-
-/// 选择应继续锁定的 reset：新鲜快照仍确认耗尽时可把锁推进到更晚窗口；
-/// 否则保留已确认失败的旧窗口，避免 98/99% 快照反向解锁。
-fn confirmed_exhaustion_reset_at(
-    previous_reset_at: Option<SystemTime>,
-    refreshed_snapshot: &CodexAccountQuotaSnapshot,
-) -> Option<i64> {
-    let refreshed_reset_at = refreshed_snapshot
-        .core_primary_window()
-        .and_then(|window| window.reset_at())
-        .map(SystemTime::from);
-    let reset_at = match (previous_reset_at, refreshed_reset_at) {
-        (Some(previous), Some(refreshed))
-            if refreshed_snapshot.fact().exhausted() && refreshed > previous =>
-        {
-            refreshed
-        }
-        (Some(previous), _) => previous,
-        (None, refreshed) => refreshed?,
-    };
-    system_time_to_unix_seconds(reset_at)
-}
-
-fn system_time_to_unix_seconds(value: SystemTime) -> Option<i64> {
-    value
-        .duration_since(UNIX_EPOCH)
-        .ok()?
-        .as_secs()
-        .try_into()
-        .ok()
-}
-
 fn passive_rate_limit_snapshot(details: &RateLimitDetails) -> Option<Map<String, Value>> {
     // 响应头的窗口属于同一次上游观测；跨响应合并会制造不存在的额度窗口。
     let mut snapshot = Map::new();
diff --git a/backend/crates/providers/openai/src/credential/quota/recovery.rs b/backend/crates/providers/openai/src/credential/quota/recovery.rs
deleted file mode 100644
index e3865d0d2..000000000
--- a/backend/crates/providers/openai/src/credential/quota/recovery.rs
+++ /dev/null
@@ -1,102 +0,0 @@
-//! 权威额度快照的 availability 转换。
-//!
-//! 已触顶的 core primary 会立即把可调度账号标为 `QuotaExhausted`；
-//! `QuotaExhausted -> Ready` 则只能由同一 credential revision 的权威 usage 快照证明：
-//! 新快照未耗尽、core primary reset 已推进到下一窗口，且该窗口用量低于 10%。
-
-use std::time::SystemTime;
-
-use gateway_core::engine::credential::AccountAvailability;
-use reqwest::StatusCode;
-use serde_json::Value;
-
-use super::snapshot::CodexAccountQuotaSnapshot;
-use crate::transport::CodexClientError;
-
-const RESET_RECOVERY_MAX_USED_PERCENT: f64 = 10.0;
-
-/// 基于成功的权威 usage 快照收敛可调度账号的额度状态。
-///
-/// 只接受上游明确拒绝使用且 core primary 触顶的证据；secondary、附加桶、
-/// credits 与 spend control 都不能单独把整个账号标成额度耗尽。
-pub(crate) fn authoritative_quota_snapshot_state(
-    current: AccountAvailability,
-    snapshot: &CodexAccountQuotaSnapshot,
-    previous_reset_at: Option<SystemTime>,
-) -> Option<AccountAvailability> {
-    match current {
-        AccountAvailability::Ready | AccountAvailability::Unknown
-            if snapshot.authoritative_core_primary_exhausted() =>
-        {
-            Some(AccountAvailability::QuotaExhausted)
-        }
-        AccountAvailability::QuotaExhausted => {
-            quota_success_state(current, snapshot, previous_reset_at)
-        }
-        AccountAvailability::Ready | AccountAvailability::Unknown => None,
-        AccountAvailability::Expired
-        | AccountAvailability::Banned
-        | AccountAvailability::Invalid => None,
-    }
-}
-
-/// 只处理 `QuotaExhausted` 的恢复。`allowed=true`、成功响应和百分比回落都不能单独覆盖
-/// 一次已确认的额度拒绝；它们在 reset 未推进时可能只是上游滞后的观测。
-///
-/// `previous_reset_at` 是写入新快照前读取的 core primary 已确认耗尽窗口。上游可能只
-/// 调整 reset 时间而尚未重置额度，因此还要求同一新鲜 primary 窗口的用量低于 10%。
-pub(crate) fn quota_success_state(
-    current: AccountAvailability,
-    snapshot: &CodexAccountQuotaSnapshot,
-    previous_reset_at: Option<SystemTime>,
-) -> Option<AccountAvailability> {
-    if current != AccountAvailability::QuotaExhausted || snapshot.fact().exhausted() {
-        return None;
-    }
-    let previous_reset_at = previous_reset_at?;
-    let primary_window = snapshot.core_primary_window()?;
-    let refreshed_reset_at = primary_window.reset_at().map(SystemTime::from)?;
-    let used_percent = primary_window.used_percent()?;
-    (refreshed_reset_at > previous_reset_at && used_percent < RESET_RECOVERY_MAX_USED_PERCENT)
-        .then_some(AccountAvailability::Ready)
-}
-
-pub(crate) fn quota_state_transition(error: &CodexClientError) -> Option<AccountAvailability> {
-    let CodexClientError::Upstream { status, body, .. } = error else {
-        return None;
-    };
-    if *status == StatusCode::PAYMENT_REQUIRED && is_deactivated_workspace(body) {
-        return Some(AccountAvailability::Banned);
-    }
-    match *status {
-        // 402：真额度耗尽 → QuotaExhausted（worker 按 reset_at 自动恢复）。
-        StatusCode::PAYMENT_REQUIRED => Some(AccountAvailability::QuotaExhausted),
-        // usage 401/403 不能单独判定账号不可用：保持现有状态，交给 OAuth 或真实请求确认。
-        // 429/503 同样不写 availability，仅记失败待重试。
-        StatusCode::UNAUTHORIZED
-        | StatusCode::FORBIDDEN
-        | StatusCode::TOO_MANY_REQUESTS
-        | StatusCode::SERVICE_UNAVAILABLE => None,
-        _ => None,
-    }
-}
-
-/// 配额接口将账号变为非 ready 状态时可安全持久化的上游原因码。
-pub(crate) fn quota_state_reason(error: &CodexClientError) -> Option<&'static str> {
-    match quota_state_transition(error)? {
-        AccountAvailability::Banned => Some("deactivated_workspace"),
-        AccountAvailability::QuotaExhausted => Some("payment_required"),
-        AccountAvailability::Unknown
-        | AccountAvailability::Ready
-        | AccountAvailability::Expired
-        | AccountAvailability::Invalid => None,
-    }
-}
-
-fn is_deactivated_workspace(body: &str) -> bool {
-    serde_json::from_str::<Value>(body)
-        .ok()
-        .is_some_and(|value| {
-            value.pointer("/detail/code").and_then(Value::as_str) == Some("deactivated_workspace")
-        })
-}
diff --git a/backend/crates/providers/openai/src/credential/quota/snapshot.rs b/backend/crates/providers/openai/src/credential/quota/snapshot.rs
index 995640a70..5382e4313 100644
--- a/backend/crates/providers/openai/src/credential/quota/snapshot.rs
+++ b/backend/crates/providers/openai/src/credential/quota/snapshot.rs
@@ -7,19 +7,17 @@ use std::time::{Duration, SystemTime};
 
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountQuotaSignals, CredentialRevision, ProviderAccountId, QuotaObservation,
+    AccountQuotaSignals, CredentialRevision, ProviderAccountId, QuotaEvidence, QuotaObservation,
+    QuotaState,
 };
 use serde_json::{Map, Value};
 
 use super::{CodexCredentialQuotaError, QUOTA_SCHEDULING_TTL};
 
-const CORE_PRIMARY_WINDOW_KEY: &str = "core-primary";
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct CodexQuotaFact {
     remaining_percent: Option<u8>,
     resets_at: Option<DateTime<Utc>>,
-    exhausted: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -112,7 +110,7 @@ pub struct CodexAccountQuotaSnapshot {
     credential_revision: CredentialRevision,
     observed_at: SystemTime,
     fact: CodexQuotaFact,
-    authoritative_core_primary_exhausted: bool,
+    quota: QuotaState,
     windows: Vec<CodexQuotaWindow>,
 }
 
@@ -143,54 +141,14 @@ impl CodexAccountQuotaSnapshot {
     }
 
     #[must_use]
-    pub(crate) fn core_primary_window(&self) -> Option<&CodexQuotaWindow> {
-        self.windows
-            .iter()
-            .find(|window| window.key() == CORE_PRIMARY_WINDOW_KEY)
+    pub const fn quota(&self) -> QuotaState {
+        self.quota
     }
 
-    /// 上游成功 usage 明确拒绝请求，且 canonical core primary 已确认触顶。
+    /// 将已持久化的规范化事实覆盖到 raw JSON 展示快照上。
     #[must_use]
-    pub(crate) const fn authoritative_core_primary_exhausted(&self) -> bool {
-        self.authoritative_core_primary_exhausted
-    }
-
-    /// 投影滚动已过期窗口：`reset_at` 已过的窗口 `used_percent=0`、
-    /// `limit_reached=false`、`reset_at` 滚到下一个周期（reset 到期自动归零）。
-    /// 只作用于展示/调度投影，不写回持久化 raw JSON。
-    ///
-    /// O(1) 计算：`next_reset = reset + (floor((now - reset) / window) + 1) * window`，
-    /// 不做逐周期线性循环。
-    #[must_use]
-    pub fn roll_expired_windows(mut self, now: SystemTime) -> Self {
-        for window in &mut self.windows {
-            let Some(reset_at) = window.reset_at else {
-                continue;
-            };
-            let reset = SystemTime::from(reset_at);
-            if reset > now {
-                continue;
-            }
-            window.used_percent = Some(0.0);
-            window.limit_reached = false;
-            let Some(window_seconds) = window.window_seconds.filter(|seconds| *seconds > 0) else {
-                // 没有合法窗口时长：清除已过期的 reset，等待下一次权威观测。
-                window.reset_at = None;
-                continue;
-            };
-            let elapsed = now
-                .duration_since(reset)
-                .unwrap_or(Duration::ZERO)
-                .as_secs();
-            let periods = elapsed / window_seconds + 1;
-            let Some(after) =
-                reset.checked_add(Duration::from_secs(periods.saturating_mul(window_seconds)))
-            else {
-                window.reset_at = None;
-                continue;
-            };
-            window.reset_at = Some(DateTime::<Utc>::from(after));
-        }
+    pub(crate) const fn with_quota_state(mut self, quota: QuotaState) -> Self {
+        self.quota = quota;
         self
     }
 }
@@ -205,11 +163,6 @@ impl CodexQuotaFact {
     pub const fn resets_at(&self) -> Option<DateTime<Utc>> {
         self.resets_at
     }
-
-    #[must_use]
-    pub const fn exhausted(&self) -> bool {
-        self.exhausted
-    }
 }
 
 pub fn parse_codex_quota_usage(usage: &Value) -> Result<CodexQuotaFact, CodexCredentialQuotaError> {
@@ -220,13 +173,12 @@ pub fn parse_codex_quota_usage(usage: &Value) -> Result<CodexQuotaFact, CodexCre
     for limit in canonical_rate_limits(object)? {
         aggregate.observe_rate_limit(limit.rate_limit)?;
     }
-    // spend_control 只提供 exhaustion 信号（`reached`），不生成窗口、
-    // 不参与剩余量聚合（`individual_limit` 等字段无窗口语义）。
+    // credits / spend_control 只证明文档结构已识别，不参与账号级访问结论。
     if let Some(spend_control) = object.get("spend_control") {
-        aggregate.observe_exhaustion_object(spend_control, "reached")?;
+        aggregate.observe_metadata_object(spend_control, "reached")?;
     }
     if let Some(credits) = object.get("credits") {
-        aggregate.observe_exhaustion_object(credits, "overage_limit_reached")?;
+        aggregate.observe_metadata_object(credits, "overage_limit_reached")?;
     }
     if !aggregate.recognized {
         return Err(CodexCredentialQuotaError::InvalidCredentialData);
@@ -234,22 +186,24 @@ pub fn parse_codex_quota_usage(usage: &Value) -> Result<CodexQuotaFact, CodexCre
     Ok(CodexQuotaFact {
         remaining_percent: aggregate.remaining_percent,
         resets_at: aggregate.resets_at,
-        exhausted: aggregate.exhausted,
     })
 }
 
 pub(crate) fn quota_snapshot_from_observation(
     observation: &QuotaObservation,
 ) -> Option<CodexAccountQuotaSnapshot> {
-    let observed_at = observation.observed_at?;
-    let quota = observation.quota.as_ref()?;
-    parse_account_quota_snapshot(
+    let observed_at = observation.observed_at;
+    let quota = &observation.quota;
+    let mut snapshot = parse_account_quota_snapshot(
         observation.account_id.clone(),
         observation.expected_revision,
         observed_at,
         &Value::Object(quota.expose_to_provider().clone()),
     )
-    .ok()
+    .ok()?;
+    // 归一化列是持久化权威事实；raw JSON 只负责 Provider 展示结构。
+    snapshot.quota = observation.state;
+    Some(snapshot)
 }
 
 /// 调度投影缓存 TTL：`min(常规 TTL, 最近 active reset - now)`。
@@ -275,46 +229,36 @@ pub(crate) fn quota_projection_ttl(snapshot: &CodexAccountQuotaSnapshot) -> Opti
     (!ttl.is_zero()).then_some(ttl)
 }
 
-/// 从快照的滚动窗口派生中立调度事实（`limit_reached` = 任一窗口触顶）。
+/// 从快照窗口派生容量排序事实；额度访问资格由 `QuotaState` 统一判断。
 pub(crate) fn scheduling_signals_from_snapshot(
     snapshot: &CodexAccountQuotaSnapshot,
 ) -> Option<AccountQuotaSignals> {
-    let rolled = snapshot.clone().roll_expired_windows(SystemTime::now());
-    quota_scheduling_signals(&rolled)
+    quota_scheduling_signals(snapshot)
 }
 
 pub(crate) fn quota_scheduling_signals(
     snapshot: &CodexAccountQuotaSnapshot,
 ) -> Option<AccountQuotaSignals> {
     let now = SystemTime::now();
-    let mut limit_reached = false;
     let mut remaining_rank: Option<u64> = None;
     let mut reset_at: Option<SystemTime> = None;
     for window in &snapshot.windows {
-        limit_reached |= window.limit_reached();
-        if let Some(used) = window
-            .used_percent()
-            .filter(|used| used.is_finite() && (0.0..=100.0).contains(used))
+        let window_reset_at = window.reset_at().map(SystemTime::from);
+        let observation_expired = window_reset_at.is_some_and(|reset_at| reset_at <= now);
+        if !observation_expired
+            && let Some(used) = window
+                .used_percent()
+                .filter(|used| used.is_finite() && (0.0..=100.0).contains(used))
         {
             let rank = ((100.0 - used) * 100.0).round() as u64;
             remaining_rank = Some(remaining_rank.map_or(rank, |current| current.min(rank)));
         }
-        if let Some(reset) = window
-            .reset_at()
-            .map(SystemTime::from)
-            .filter(|reset| *reset > now)
-        {
+        if let Some(reset) = window_reset_at.filter(|reset| *reset > now) {
             reset_at = Some(reset_at.map_or(reset, |current| current.min(reset)));
         }
     }
-    // 快照级 limit_reached 是调度排除的充分条件：即使没有任何窗口带
-    // percent/reset（如顶层限流标记），也必须产出信号；不能返回 None 丢失排除。
-    if limit_reached || remaining_rank.is_some() || reset_at.is_some() {
-        Some(AccountQuotaSignals::new(
-            reset_at,
-            remaining_rank,
-            limit_reached,
-        ))
+    if remaining_rank.is_some() || reset_at.is_some() {
+        Some(AccountQuotaSignals::new(reset_at, remaining_rank))
     } else {
         None
     }
@@ -330,7 +274,7 @@ pub(crate) fn parse_account_quota_snapshot(
     let object = usage
         .as_object()
         .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
-    let authoritative_core_primary_exhausted = authoritative_core_primary_exhausted(object)?;
+    let quota = authoritative_quota_state(object, observed_at)?;
     let mut windows = Vec::new();
     for limit in canonical_rate_limits(object)? {
         parse_rate_limit_windows(
@@ -352,7 +296,7 @@ pub(crate) fn parse_account_quota_snapshot(
         credential_revision,
         observed_at,
         fact,
-        authoritative_core_primary_exhausted,
+        quota,
         windows,
     })
 }
@@ -365,48 +309,73 @@ fn quota_source_order(source: &str) -> u8 {
     }
 }
 
-/// 账号状态只能由顶层 canonical Codex 额度桶的明确拒绝来改变。
-///
-/// `fact.exhausted()` 和窗口 `limit_reached` 都会聚合或继承 secondary、附加桶等事实，
-/// 因此不能单独用来将整个账号标为 `QuotaExhausted`。
-fn authoritative_core_primary_exhausted(
+/// 顶层 account-wide Codex 桶是唯一可改变账号额度访问结论的 quota 响应字段。
+fn authoritative_quota_state(
     usage: &Map<String, Value>,
-) -> Result<bool, CodexCredentialQuotaError> {
+    observed_at: SystemTime,
+) -> Result<QuotaState, CodexCredentialQuotaError> {
     let Some(rate_limit) = usage.get("rate_limit") else {
-        return Ok(false);
+        return Ok(QuotaState::observed_unknown(observed_at));
     };
     if rate_limit.is_null() {
-        return Ok(false);
+        return Ok(QuotaState::observed_unknown(observed_at));
     }
     let rate_limit = rate_limit
         .as_object()
         .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
-    if optional_bool(rate_limit, "allowed")? != Some(false) {
-        return Ok(false);
+    let allowed = optional_bool(rate_limit, "allowed")?;
+    let top_level_reached = optional_bool(rate_limit, "limit_reached")?.unwrap_or(false);
+    let primary_window = rate_limit
+        .get("primary_window")
+        .filter(|value| !value.is_null())
+        .map(|value| {
+            value
+                .as_object()
+                .ok_or(CodexCredentialQuotaError::InvalidCredentialData)
+        })
+        .transpose()?;
+    let primary_reached = primary_window
+        .map(|window| optional_bool(window, "limit_reached"))
+        .transpose()?
+        .flatten()
+        .unwrap_or(false);
+    let reset_at = primary_window
+        .and_then(|window| window.get("reset_at"))
+        .map(|value| {
+            value
+                .as_i64()
+                .filter(|value| *value > 0)
+                .and_then(|value| DateTime::<Utc>::from_timestamp(value, 0))
+                .map(SystemTime::from)
+                .ok_or(CodexCredentialQuotaError::InvalidCredentialData)
+        })
+        .transpose()?;
+
+    if allowed == Some(true) {
+        if top_level_reached || primary_reached {
+            tracing::warn!(
+                top_level_reached,
+                primary_reached,
+                "OpenAI quota returned contradictory access facts; explicit allowed=true wins"
+            );
+        }
+        return Ok(QuotaState::allowed(observed_at));
     }
-    let Some(primary_window) = rate_limit.get("primary_window") else {
-        return Ok(false);
-    };
-    if primary_window.is_null() {
-        return Ok(false);
+    if allowed == Some(false) {
+        return Ok(QuotaState::exhausted(
+            QuotaEvidence::ProviderDenied,
+            observed_at,
+            reset_at,
+        ));
     }
-    let primary_window = primary_window
-        .as_object()
-        .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
-    let primary_window_reached = optional_bool(rate_limit, "limit_reached")?.unwrap_or(false)
-        || optional_bool(primary_window, "limit_reached")?.unwrap_or(false)
-        || primary_window
-            .get("used_percent")
-            .map(|value| {
-                value
-                    .as_f64()
-                    .filter(|value| value.is_finite() && *value >= 0.0)
-                    .map(|value| value >= 100.0)
-                    .ok_or(CodexCredentialQuotaError::InvalidCredentialData)
-            })
-            .transpose()?
-            .unwrap_or(false);
-    Ok(primary_window_reached)
+    if top_level_reached || primary_reached {
+        return Ok(QuotaState::exhausted(
+            QuotaEvidence::AccountLimitReached,
+            observed_at,
+            reset_at,
+        ));
+    }
+    Ok(QuotaState::observed_unknown(observed_at))
 }
 
 /// 一个规范化后的限流桶：`key` 用于稳定区分窗口，`source` 用于展示分组。
@@ -523,10 +492,9 @@ fn parse_rate_limit_windows(
     let object = value
         .as_object()
         .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
-    // 顶层限流标记是快照级事实：任一窗口都要继承所属
-    // rate_limit 的 `limit_reached=true` / `allowed=false`。
-    let top_level_reached = optional_bool(object, "limit_reached")?.unwrap_or(false)
-        || optional_bool(object, "allowed")?.is_some_and(|allowed| !allowed);
+    let allowed = optional_bool(object, "allowed")?;
+    let top_level_reached = allowed != Some(true)
+        && (optional_bool(object, "limit_reached")?.unwrap_or(false) || allowed == Some(false));
     for (name, role) in [
         ("primary_window", CodexQuotaWindowRole::Primary),
         ("secondary_window", CodexQuotaWindowRole::Secondary),
@@ -564,12 +532,12 @@ fn parse_rate_limit_windows(
                     .ok_or(CodexCredentialQuotaError::InvalidCredentialData)
             })
             .transpose()?;
-        let limit_reached = top_level_reached
-            || window
-                .get("limit_reached")
-                .and_then(Value::as_bool)
-                .unwrap_or(false)
-            || used_percent.is_some_and(|used| used >= 100.0);
+        let limit_reached = allowed != Some(true)
+            && (top_level_reached
+                || window
+                    .get("limit_reached")
+                    .and_then(Value::as_bool)
+                    .unwrap_or(false));
         let kind = quota_window_kind(window_seconds);
         output.push(CodexQuotaWindow {
             key: format!("{}-{}", quota_key(key_source), quota_role_name(role, kind)),
@@ -649,7 +617,6 @@ const fn quota_role_name(role: CodexQuotaWindowRole, kind: CodexQuotaWindowKind)
 #[derive(Default)]
 struct QuotaAggregate {
     recognized: bool,
-    exhausted: bool,
     remaining_percent: Option<u8>,
     resets_at: Option<DateTime<Utc>>,
 }
@@ -660,8 +627,8 @@ impl QuotaAggregate {
             .as_object()
             .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
         self.recognized = true;
-        self.exhausted |= optional_bool(object, "limit_reached")?.unwrap_or(false);
-        self.exhausted |= optional_bool(object, "allowed")?.is_some_and(|allowed| !allowed);
+        let _ = optional_bool(object, "limit_reached")?;
+        let _ = optional_bool(object, "allowed")?;
         for key in ["primary_window", "secondary_window"] {
             if let Some(window) = object.get(key) {
                 self.observe_window(window)?;
@@ -682,8 +649,6 @@ impl QuotaAggregate {
                 .as_f64()
                 .filter(|value| value.is_finite() && *value >= 0.0)
                 .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
-            // 子窗口触顶（used>=100）是快照级 exhaustion 事实。
-            self.exhausted |= used >= 100.0;
             let remaining = (100.0 - used).clamp(0.0, 100.0).round() as u8;
             self.remaining_percent = Some(
                 self.remaining_percent
@@ -702,7 +667,7 @@ impl QuotaAggregate {
         Ok(())
     }
 
-    fn observe_exhaustion_object(
+    fn observe_metadata_object(
         &mut self,
         value: &Value,
         key: &str,
@@ -714,7 +679,7 @@ impl QuotaAggregate {
             .as_object()
             .ok_or(CodexCredentialQuotaError::InvalidCredentialData)?;
         self.recognized = true;
-        self.exhausted |= optional_bool(object, key)?.unwrap_or(false);
+        let _ = optional_bool(object, key)?;
         Ok(())
     }
 }
diff --git a/backend/crates/providers/openai/src/credential/refresh.rs b/backend/crates/providers/openai/src/credential/refresh.rs
index c9f0bd1cf..4602b41f2 100644
--- a/backend/crates/providers/openai/src/credential/refresh.rs
+++ b/backend/crates/providers/openai/src/credential/refresh.rs
@@ -6,7 +6,9 @@ use std::time::{Duration, SystemTime};
 
 use chrono::{DateTime, Utc};
 use futures::{StreamExt as _, stream};
-use gateway_core::engine::credential::{AccountAvailability, ProviderAccount, ProviderAccountId};
+use gateway_core::engine::credential::{
+    AccountErrorReason, CredentialState, ProviderAccount, ProviderAccountId,
+};
 use gateway_core::provider_ports::{
     ProviderCredentialStatePort, ProviderLeaseAcquisition, ProviderLeasePort, ProviderLeaseRequest,
     ProviderRefreshCapacityRequest, ProviderRefreshLeaseRequest, ProviderRefreshPolicy,
@@ -253,7 +255,8 @@ impl CodexCredentialRefreshService {
             return self
                 .persist_terminal(
                     &due.account,
-                    AccountAvailability::Expired,
+                    CredentialState::Expired,
+                    AccountErrorReason::CredentialExpired,
                     "refresh_recovery_window_exhausted",
                     CodexCredentialRefreshOutcome::Invalidated { account_id },
                 )
@@ -293,7 +296,8 @@ impl CodexCredentialRefreshService {
             Err(RefreshFailure::InvalidGrant) => {
                 self.persist_terminal(
                     &due.account,
-                    AccountAvailability::Expired,
+                    CredentialState::Expired,
+                    AccountErrorReason::CredentialExpired,
                     "refresh_invalid_grant",
                     CodexCredentialRefreshOutcome::Invalidated { account_id },
                 )
@@ -302,7 +306,8 @@ impl CodexCredentialRefreshService {
             Err(RefreshFailure::Banned) => {
                 self.persist_terminal(
                     &due.account,
-                    AccountAvailability::Banned,
+                    CredentialState::Banned,
+                    AccountErrorReason::AccountBanned,
                     "account_banned",
                     CodexCredentialRefreshOutcome::Banned { account_id },
                 )
@@ -353,11 +358,9 @@ impl CodexCredentialRefreshService {
                 && account.enabled()
                 && account.has_refresh_token()
                 && !excluded.contains(account.id())
-                && !matches!(
-                    account.availability(),
-                    AccountAvailability::Expired
-                        | AccountAvailability::Banned
-                        | AccountAvailability::Invalid
+                && matches!(
+                    account.credential_state(),
+                    CredentialState::Unknown | CredentialState::Ready
                 )
                 && refresh_due_at(account, policy, now).is_some()
         });
@@ -463,7 +466,8 @@ impl CodexCredentialRefreshService {
     async fn persist_terminal(
         &self,
         account: &ProviderAccount,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
+        error_reason: AccountErrorReason,
         reason: &'static str,
         outcome: CodexCredentialRefreshOutcome,
     ) -> Result<CodexCredentialRefreshOutcome, CodexCredentialRefreshError> {
@@ -478,10 +482,11 @@ impl CodexCredentialRefreshService {
         }
         match self
             .repository
-            .apply_state_with_message(
+            .apply_state_with_reason(
                 account,
-                availability,
+                credential_state,
                 SystemTime::now(),
+                Some(error_reason),
                 Some(reason.to_owned()),
             )
             .await
@@ -489,7 +494,7 @@ impl CodexCredentialRefreshService {
             Ok(()) => {
                 tracing::warn!(
                     account_id = %account.id(),
-                    ?availability,
+                    ?credential_state,
                     reason,
                     access_token_expires_at = ?account.access_token_expires_at()
                         .map(DateTime::<Utc>::from),
diff --git a/backend/crates/providers/openai/src/credential/repository.rs b/backend/crates/providers/openai/src/credential/repository.rs
index 7d6131298..c2aba671d 100644
--- a/backend/crates/providers/openai/src/credential/repository.rs
+++ b/backend/crates/providers/openai/src/credential/repository.rs
@@ -5,8 +5,8 @@ use std::time::SystemTime;
 
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
-    CredentialRevision, ProviderAccount, ProviderAccountId, ProviderAccountStore,
+    AccountErrorReason, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
+    CredentialRevision, CredentialState, ProviderAccount, ProviderAccountId, ProviderAccountStore,
     ProviderAccountUpdate,
 };
 use gateway_core::routing::ProviderKind;
@@ -220,34 +220,46 @@ impl CodexCredentialRepository {
     pub async fn apply_state(
         &self,
         account: &ProviderAccount,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
         observed_at: SystemTime,
     ) -> Result<(), CredentialRepositoryError> {
-        self.apply_state_with_message(account, availability, observed_at, None)
-            .await
+        self.apply_state_with_reason(
+            account,
+            credential_state,
+            observed_at,
+            credential_state.error_reason(),
+            None,
+        )
+        .await
     }
 
-    /// 带上游错误描述的状态写入；上游 message 优先，终态缺失 message 时写稳定兜底，
-    /// 恢复 `Ready` 时清空。
-    pub async fn apply_state_with_message(
+    /// 写入凭据事实及其稳定错误原因；额度事实不经过此入口。
+    pub async fn apply_state_with_reason(
         &self,
         account: &ProviderAccount,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
         observed_at: SystemTime,
+        error_reason: Option<AccountErrorReason>,
         message: Option<String>,
     ) -> Result<(), CredentialRepositoryError> {
         if !account.enabled() {
             return Ok(());
         }
-        let message = message
-            .filter(|value| !value.trim().is_empty())
-            .or_else(|| availability.fallback_error_reason().map(str::to_owned));
+        let (error_reason, message) = if credential_state == CredentialState::Ready {
+            (None, None)
+        } else {
+            (
+                error_reason.or_else(|| credential_state.error_reason()),
+                message.filter(|value| !value.trim().is_empty()),
+            )
+        };
         self.store
             .apply_state_change(AccountStateChange {
                 account_id: account.id().clone(),
                 expected_revision: account.revision(),
-                availability,
+                credential_state,
                 observed_at,
+                error_reason,
                 message,
             })
             .await?;
diff --git a/backend/crates/providers/openai/src/credential/selector.rs b/backend/crates/providers/openai/src/credential/selector.rs
index 7c714cb4e..b6c2c18ff 100644
--- a/backend/crates/providers/openai/src/credential/selector.rs
+++ b/backend/crates/providers/openai/src/credential/selector.rs
@@ -6,9 +6,10 @@ use std::sync::{Arc, Mutex};
 use std::time::{Duration, SystemTime};
 
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountAvailabilityPolicy, AccountCandidate, AccountFeedbackStats,
+    AccountCandidate, AccountEligibilityPolicy, AccountErrorReason, AccountFeedbackStats,
     AccountRuntimeSignals, AccountSchedulingBlocker, AccountSelectionContext, AccountSelector,
-    PreferredAccountSelection, ProviderAccount, ProviderAccountId,
+    AccountStatus, CredentialState, PreferredAccountSelection, ProviderAccount, ProviderAccountId,
+    QuotaEvidence,
 };
 use gateway_core::engine::{AttemptContext, ContinuationAttempt};
 use gateway_core::provider_ports::{
@@ -57,8 +58,8 @@ pub enum CodexAccountFailure {
     QuotaExhausted,
     /// 当前用量窗口已耗尽；到重置时间后可自动恢复。
     UsageLimitExhausted {
-        /// 上游返回的窗口重置时长。
-        retry_after: Option<Duration>,
+        /// 上游返回的窗口绝对重置时刻。
+        reset_at: Option<SystemTime>,
     },
     /// 账号触发临时用量限制。
     RateLimited {
@@ -74,21 +75,6 @@ pub enum CodexAccountFailure {
     CloudflarePathBlocked,
 }
 
-impl CodexAccountFailure {
-    /// 上游未提供可展示错误文本时，保留已分类的稳定原因。
-    const fn fallback_error_reason(self) -> Option<&'static str> {
-        match self {
-            Self::CredentialExpired => Some("upstream_credential_expired"),
-            Self::IdentityVerificationRequired => Some("upstream_identity_verification_required"),
-            Self::Banned => Some("upstream_account_banned"),
-            Self::QuotaExhausted => Some("upstream_quota_exhausted"),
-            Self::UsageLimitExhausted { .. } => Some("upstream_usage_limit_exhausted"),
-            Self::CloudflarePathBlocked => Some("upstream_cloudflare_path_blocked"),
-            Self::RateLimited { .. } | Self::CloudflareChallenge { .. } => None,
-        }
-    }
-}
-
 #[derive(Debug, Clone, Copy)]
 struct RiskRecoveryState {
     challenge_count: u32,
@@ -127,7 +113,6 @@ pub struct CodexCredentialSelector {
     cookie_policy: CodexCookiePolicy,
     risk_recovery: Mutex<HashMap<String, RiskRecoveryState>>,
     account_feedback: Arc<AccountFeedbackStats>,
-    skip_exhausted: bool,
 }
 
 enum SessionAffinityLookup {
@@ -263,7 +248,6 @@ impl CodexCredentialSelector {
         agent_identity: Arc<CodexAgentIdentityTaskService>,
         account_feedback: Arc<AccountFeedbackStats>,
         cookie_policy: CodexCookiePolicy,
-        skip_exhausted: bool,
     ) -> Self {
         Self {
             provider_kind,
@@ -277,7 +261,6 @@ impl CodexCredentialSelector {
             cookie_policy,
             risk_recovery: Mutex::new(HashMap::new()),
             account_feedback,
-            skip_exhausted,
         }
     }
 
@@ -310,24 +293,17 @@ impl CodexCredentialSelector {
         if !diagnostic {
             self.quota.prepare_scheduling(&accounts).await;
         }
-        // 429 临时限流（Redis 冷却）中的账号即使额度正常也不参与调度，
-        // 到期后冷却过期自动恢复。诊断请求（连接测试）绕过冷却，需要真实探测。
-        let accounts = if diagnostic {
-            accounts
-        } else {
-            let mut retained = Vec::with_capacity(accounts.len());
-            for account in accounts {
-                let cooling = self
+        let mut rate_limits = HashMap::with_capacity(accounts.len());
+        if !diagnostic {
+            for account in &accounts {
+                let until = self
                     .quota
-                    .rate_limited_until(account.id(), account.revision())
+                    .rate_limited_until(account.id())
                     .await
                     .unwrap_or(None);
-                if cooling.is_none() {
-                    retained.push(account);
-                }
+                rate_limits.insert(account.id().clone(), until);
             }
-            retained
-        };
+        }
         let account_ids = accounts
             .iter()
             .map(|account| account.id().clone())
@@ -352,11 +328,12 @@ impl CodexCredentialSelector {
                         last_started_at: None,
                         quota_reset_at: None,
                         quota_remaining_rank: None,
-                        quota_limit_reached: false,
+                        rate_limited_until: None,
                         failure_rate_basis_points: None,
                         first_output_latency_ms: None,
                     })
                     .with_provider_quota(self.quota.scheduling_signals(&account))
+                    .with_rate_limit(rate_limits.get(account.id()).copied().flatten())
                     .with_runtime_health(health.0, health.1);
                 AccountCandidate { account, signals }
             })
@@ -383,41 +360,6 @@ impl CodexCredentialSelector {
             return Err(CredentialSelectionError::NoEligibleCredential);
         }
         let pinned_account = required_account.or_else(|| continuation_account.clone());
-        let preserve_native_continuation_state = matches!(
-            request.attempt.continuation_attempt(),
-            ContinuationAttempt::Native
-        ) && continuation_account.is_some();
-        // skip_exhausted 语义：true 时排除任一窗口触顶（limit_reached）的账号，
-        // 仅由上游 429 兜底；false 时保留全部候选（含 QuotaExhausted 的放宽投影）。
-        // 保留原始账号供 revision-fenced 凭据加载，用影子候选承载资格放宽。
-        let scheduling_candidates = if diagnostic {
-            // 连接测试必须实际探测指定账号；额度快照只影响常规调度。
-            candidates.clone()
-        } else if self.skip_exhausted {
-            candidates
-                .iter()
-                .filter(|candidate| !candidate.signals.quota_limit_reached)
-                .cloned()
-                .collect::<Vec<_>>()
-        } else {
-            candidates
-                .iter()
-                .cloned()
-                .map(|mut candidate| {
-                    // 已命中 previous_response_id 的 native continuation 先检查原账号。
-                    // 即使常规调度允许探测额度耗尽账号，也必须保留原账号真实状态，
-                    // 由 Coordinator 据此切换到可携带重放，而非伪装为 Ready。
-                    if !preserve_native_continuation_state
-                        || pinned_account.as_ref() != Some(candidate.account.id())
-                    {
-                        candidate.account =
-                            quota_exhausted_scheduling_projection(&candidate.account);
-                    }
-                    candidate
-                })
-                .collect::<Vec<_>>()
-        };
-        let scheduling_candidates = scheduling_candidates.as_slice();
         let mut affinity = if diagnostic {
             AffinitySelection::default()
         } else {
@@ -432,18 +374,6 @@ impl CodexCredentialSelector {
             .prepare_cyber_policy_scope(cyber_policy_session_key)
             .await;
         let mut excluded = request.attempt.excluded_accounts().clone();
-        if !diagnostic
-            && preserve_native_continuation_state
-            && let Some(pinned) = pinned_account.as_ref()
-            && candidates.iter().any(|candidate| {
-                candidate.account.id() == pinned && candidate.signals.quota_limit_reached
-            })
-        {
-            // `skip_exhausted = false` 只允许普通新请求探测可疑账号；已绑定的
-            // native response handle 先将真实触顶状态交给 Coordinator，随后才可
-            // 通过 ReplayAny 按当前调度策略换号。
-            excluded.insert(pinned.clone());
-        }
         if let Some(state) = cyber_policy_scope
             .as_ref()
             .and_then(|scope| scope.state.as_ref())
@@ -476,13 +406,13 @@ impl CodexCredentialSelector {
                 excluded_accounts: excluded.clone(),
                 preferred_account: preferred.clone(),
                 round_robin_cursor,
-                availability: if diagnostic {
-                    AccountAvailabilityPolicy::BypassForDiagnostic
+                eligibility: if diagnostic {
+                    AccountEligibilityPolicy::BypassForDiagnostic
                 } else {
-                    AccountAvailabilityPolicy::Enforce
+                    AccountEligibilityPolicy::Enforce
                 },
             };
-            let Some(selection) = AccountSelector.select(scheduling_candidates, &context) else {
+            let Some(selection) = AccountSelector.select(&candidates, &context) else {
                 return match shortest_retry {
                     Some(retry_after) => Err(CredentialSelectionError::CapacityUnavailable {
                         retry_after: Some(retry_after),
@@ -597,10 +527,15 @@ impl CodexCredentialSelector {
             self.clear_session_affinity(key).await;
             return AffinitySelection::escaped(account_id, AffinityEscapeReason::HardUnavailable);
         };
-        if candidate.account.is_schedulable(now) {
+        if candidate
+            .account
+            .status_projection(now, candidate.signals.rate_limited_until)
+            .status
+            == AccountStatus::Normal
+        {
             return AffinitySelection::preferred(account_id);
         }
-        let reason = affinity_unavailable_reason(&candidate.account, now);
+        let reason = affinity_unavailable_reason(candidate, now);
         self.clear_session_affinity(key).await;
         AffinitySelection::escaped(account_id, reason)
     }
@@ -749,9 +684,7 @@ impl CodexCredentialSelector {
         message: Option<String>,
     ) -> Result<(), CredentialSelectionError> {
         let now = SystemTime::now();
-        let message = message
-            .filter(|value| !value.trim().is_empty())
-            .or_else(|| failure.fallback_error_reason().map(str::to_owned));
+        let message = message.filter(|value| !value.trim().is_empty());
         match failure {
             CodexAccountFailure::CredentialExpired => {
                 if account.authentication_kind() == CODEX_AUTHENTICATION_KIND_OAUTH
@@ -772,29 +705,51 @@ impl CodexCredentialSelector {
                     );
                     return Ok(());
                 }
-                self.apply_state_with_message(account, AccountAvailability::Expired, now, message)
-                    .await
-            }
-            CodexAccountFailure::IdentityVerificationRequired => {
-                self.apply_state_with_message(account, AccountAvailability::Invalid, now, message)
-                    .await
-            }
-            CodexAccountFailure::Banned => {
-                self.apply_state_with_message(account, AccountAvailability::Banned, now, message)
-                    .await
-            }
-            // 402：真额度耗尽，由 quota worker 按窗口 reset 自动恢复。
-            CodexAccountFailure::QuotaExhausted
-            | CodexAccountFailure::UsageLimitExhausted { .. } => {
-                self.apply_state_with_message(
+                self.apply_credential_state(
                     account,
-                    AccountAvailability::QuotaExhausted,
+                    CredentialState::Expired,
+                    AccountErrorReason::AccessTokenExpired,
                     now,
                     message,
                 )
                 .await
             }
-            // 429：临时限流只写 quota，availability 不改变。
+            CodexAccountFailure::IdentityVerificationRequired => {
+                self.apply_credential_state(
+                    account,
+                    CredentialState::Invalid,
+                    AccountErrorReason::AccountUnverified,
+                    now,
+                    message,
+                )
+                .await
+            }
+            CodexAccountFailure::Banned => {
+                self.apply_credential_state(
+                    account,
+                    CredentialState::Banned,
+                    AccountErrorReason::AccountBanned,
+                    now,
+                    message,
+                )
+                .await
+            }
+            CodexAccountFailure::QuotaExhausted => self
+                .quota
+                .record_confirmed_exhaustion(account, QuotaEvidence::PaymentRequired, None, now)
+                .await
+                .map_err(|_| CredentialSelectionError::Store),
+            CodexAccountFailure::UsageLimitExhausted { reset_at } => self
+                .quota
+                .record_confirmed_exhaustion(
+                    account,
+                    QuotaEvidence::UsageLimitReached,
+                    reset_at,
+                    now,
+                )
+                .await
+                .map_err(|_| CredentialSelectionError::Store),
+            // 429：临时限流只写运行时冷却，不改变凭据或额度事实。
             CodexAccountFailure::RateLimited { retry_after } => {
                 self.quota
                     .apply_rate_limit_429(account, retry_after, now)
@@ -802,7 +757,7 @@ impl CodexCredentialSelector {
                     .map_err(|_| CredentialSelectionError::Store)?;
                 Ok(())
             }
-            // Cloudflare 挑战：内存退避表（记录风险计数），不写 availability。
+            // Cloudflare 挑战：内存退避表（记录风险计数），不写账号事实。
             CodexAccountFailure::CloudflareChallenge { retry_after } => {
                 let delay = self.cloudflare_challenge_delay(account.id(), now, retry_after);
                 let recovery = now
@@ -815,9 +770,10 @@ impl CodexCredentialSelector {
             CodexAccountFailure::CloudflarePathBlocked => {
                 let blocked = self.record_cloudflare_path_block(account.id(), now);
                 if blocked >= CLOUDFLARE_PATH_BLOCK_THRESHOLD {
-                    self.apply_state_with_message(
+                    self.apply_credential_state(
                         account,
-                        AccountAvailability::Invalid,
+                        CredentialState::Invalid,
+                        AccountErrorReason::CredentialInvalid,
                         now,
                         message,
                     )
@@ -830,15 +786,22 @@ impl CodexCredentialSelector {
         }
     }
 
-    async fn apply_state_with_message(
+    async fn apply_credential_state(
         &self,
         account: &ProviderAccount,
-        availability: AccountAvailability,
+        credential_state: CredentialState,
+        error_reason: AccountErrorReason,
         observed_at: SystemTime,
         message: Option<String>,
     ) -> Result<(), CredentialSelectionError> {
         self.repository
-            .apply_state_with_message(account, availability, observed_at, message)
+            .apply_state_with_reason(
+                account,
+                credential_state,
+                observed_at,
+                Some(error_reason),
+                message,
+            )
             .await?;
         Ok(())
     }
@@ -895,29 +858,34 @@ impl CodexCredentialSelector {
         let Ok(current) = self.current_account(account.id()).await else {
             return;
         };
-        // QuotaExhausted 只能由结构化额度事实解除；一次成功响应本身不能证明额度已经恢复。
         if current.provider() != &self.provider_kind
             || current.revision() != account.revision()
             || !current.enabled()
-            || !matches!(
-                current.availability(),
-                AccountAvailability::Unknown
-                    | AccountAvailability::Expired
-                    | AccountAvailability::Invalid
-                    | AccountAvailability::Banned
-            )
         {
             return;
         }
+        let observed_at = SystemTime::now();
+        if current.credential_state() != CredentialState::Ready
+            && let Err(error) = self
+                .repository
+                .apply_state(&current, CredentialState::Ready, observed_at)
+                .await
+        {
+            tracing::warn!(
+                account_id = %account.id(),
+                error = %error,
+                "OpenAI credential recovery after successful upstream response failed"
+            );
+        }
         if let Err(error) = self
-            .repository
-            .apply_state(&current, AccountAvailability::Ready, SystemTime::now())
+            .quota
+            .record_successful_inference(&current, observed_at)
             .await
         {
             tracing::warn!(
                 account_id = %account.id(),
                 error = %error,
-                "OpenAI account state recovery after successful upstream response failed"
+                "OpenAI quota recovery after successful upstream response failed"
             );
         }
     }
@@ -1045,30 +1013,19 @@ impl CodexCredentialSelector {
     }
 }
 
-fn quota_exhausted_scheduling_projection(account: &ProviderAccount) -> ProviderAccount {
-    if account.availability() == AccountAvailability::QuotaExhausted {
-        return account
-            .clone()
-            .with_runtime_state(account.enabled(), AccountAvailability::Ready);
-    }
-    account.clone()
-}
-
-fn affinity_unavailable_reason(account: &ProviderAccount, now: SystemTime) -> AffinityEscapeReason {
-    if !account.enabled()
-        || account
-            .access_token_expires_at()
-            .is_some_and(|expires_at| expires_at <= now)
+fn affinity_unavailable_reason(
+    candidate: &AccountCandidate,
+    now: SystemTime,
+) -> AffinityEscapeReason {
+    match candidate
+        .account
+        .status_projection(now, candidate.signals.rate_limited_until)
+        .status
     {
-        return AffinityEscapeReason::HardUnavailable;
-    }
-    match account.availability() {
-        AccountAvailability::QuotaExhausted => AffinityEscapeReason::QuotaExhausted,
-        AccountAvailability::Unknown
-        | AccountAvailability::Ready
-        | AccountAvailability::Expired
-        | AccountAvailability::Banned
-        | AccountAvailability::Invalid => AffinityEscapeReason::HardUnavailable,
+        AccountStatus::QuotaExhausted => AffinityEscapeReason::QuotaExhausted,
+        AccountStatus::RateLimited => AffinityEscapeReason::Cooldown,
+        AccountStatus::Normal => AffinityEscapeReason::SelectionInvariant,
+        AccountStatus::Disabled | AccountStatus::Error => AffinityEscapeReason::HardUnavailable,
     }
 }
 
diff --git a/backend/crates/providers/openai/src/lib.rs b/backend/crates/providers/openai/src/lib.rs
index af0189beb..d1ae276bf 100644
--- a/backend/crates/providers/openai/src/lib.rs
+++ b/backend/crates/providers/openai/src/lib.rs
@@ -110,7 +110,6 @@ pub async fn initialize(
         Arc::clone(&agent_identity),
         ports.cooldowns(),
     ));
-    let quota_skip_exhausted = config.quota_skip_exhausted();
     let selector = Arc::new(CodexCredentialSelector::new(
         provider_kind.clone(),
         repository.clone(),
@@ -122,7 +121,6 @@ pub async fn initialize(
         Arc::clone(&agent_identity),
         Arc::clone(&account_feedback),
         CodexCookiePolicy::official().map_err(|_| OpenAiInitializeError::CookiePolicy)?,
-        quota_skip_exhausted,
     ));
     let core_provider: Arc<dyn Provider> = Arc::new(
         CodexProvider::new(
diff --git a/backend/crates/providers/openai/src/provider.rs b/backend/crates/providers/openai/src/provider.rs
index 8228b2c71..974cf6332 100644
--- a/backend/crates/providers/openai/src/provider.rs
+++ b/backend/crates/providers/openai/src/provider.rs
@@ -1704,13 +1704,11 @@ fn map_selection_error(error: CredentialSelectionError) -> ProviderError {
 struct MappedProviderFailure {
     error: ProviderError,
     account_failure: Option<CodexAccountFailure>,
-    /// 原始上游错误描述，随 availability 状态一并持久化。
+    /// 原始上游错误描述，仅在凭据错误状态下持久化。
     error_message: Option<String>,
     cyber_policy_failure: bool,
     set_cookie_headers: Vec<String>,
     rate_limit_headers: Vec<(String, String)>,
-    /// 结构化 usage-limit 错误给出的窗口 reset（Unix 秒）。
-    confirmed_exhaustion_reset_at: Option<i64>,
     observation: Option<ProviderResponseObservation>,
     capture_response_cookies: bool,
 }
@@ -1724,7 +1722,6 @@ impl MappedProviderFailure {
             cyber_policy_failure: false,
             set_cookie_headers: Vec::new(),
             rate_limit_headers: Vec::new(),
-            confirmed_exhaustion_reset_at: None,
             observation: None,
             capture_response_cookies: false,
         }
@@ -1882,18 +1879,6 @@ async fn apply_failure(
         failure.account_failure,
         Some(CodexAccountFailure::QuotaExhausted | CodexAccountFailure::UsageLimitExhausted { .. })
     );
-    if needs_authoritative_quota_refresh
-        && let Err(error) = context
-            .quota
-            .record_confirmed_exhaustion(account, failure.confirmed_exhaustion_reset_at)
-            .await
-    {
-        tracing::warn!(
-            account_id = %account.id(),
-            error = %error,
-            "Failed to project confirmed OpenAI quota exhaustion"
-        );
-    }
     if failure.cyber_policy_failure {
         context
             .selector
@@ -2186,12 +2171,15 @@ fn map_upstream_failure(
     }
     MappedProviderFailure {
         error,
-        account_failure: account_failure(category, failure.retry_after_seconds),
+        account_failure: account_failure(
+            category,
+            failure.retry_after_seconds,
+            failure.usage_limit_resets_at,
+        ),
         error_message: failure.client_message,
         cyber_policy_failure,
         set_cookie_headers: failure.set_cookie_headers,
         rate_limit_headers: failure.rate_limit_headers,
-        confirmed_exhaustion_reset_at: failure.usage_limit_resets_at,
         observation,
         capture_response_cookies: !matches!(
             category,
@@ -2245,6 +2233,7 @@ const fn upstream_send_state(phase: CodexUpstreamSendPhase) -> UpstreamSendState
 fn account_failure(
     category: CodexFailureCategory,
     retry_after_seconds: Option<u64>,
+    usage_limit_resets_at: Option<i64>,
 ) -> Option<CodexAccountFailure> {
     match category {
         CodexFailureCategory::CredentialExpired => Some(CodexAccountFailure::CredentialExpired),
@@ -2254,7 +2243,11 @@ fn account_failure(
         CodexFailureCategory::Banned => Some(CodexAccountFailure::Banned),
         CodexFailureCategory::UsageLimitExhausted => {
             Some(CodexAccountFailure::UsageLimitExhausted {
-                retry_after: retry_after_seconds.map(Duration::from_secs),
+                reset_at: usage_limit_resets_at
+                    .and_then(|seconds| u64::try_from(seconds).ok())
+                    .and_then(|seconds| {
+                        SystemTime::UNIX_EPOCH.checked_add(Duration::from_secs(seconds))
+                    }),
             })
         }
         CodexFailureCategory::RateLimited => Some(CodexAccountFailure::RateLimited {
diff --git a/backend/crates/providers/openai/tests/admin.rs b/backend/crates/providers/openai/tests/admin.rs
index a137dd7eb..e136a9246 100644
--- a/backend/crates/providers/openai/tests/admin.rs
+++ b/backend/crates/providers/openai/tests/admin.rs
@@ -5,9 +5,7 @@ use std::time::{Duration, SystemTime};
 
 use chrono::{DateTime, TimeZone as _, Utc};
 use futures::future::BoxFuture;
-use gateway_admin::model::accounts::{
-    AccountAvailability as AdminAccountAvailability, AccountRecord,
-};
+use gateway_admin::model::accounts::AccountRecord;
 use gateway_admin::model::observability::{
     CurrencyCost, DesktopReleaseStatus, ProviderBillingInput,
 };
@@ -20,8 +18,8 @@ use gateway_admin::model::provider_credentials::{
 use gateway_admin::model::{MutationActor, MutationContext, Revision};
 use gateway_admin::ports::provider::ProviderAdminErrorKind;
 use gateway_core::engine::credential::{
-    AccountAvailability as CoreAccountAvailability, AccountStateChange, CredentialRevision,
-    OpaqueProviderData, ProviderAccount, ProviderAccountId, ProviderAccountStore, QuotaObservation,
+    CredentialRevision, CredentialState, OpaqueProviderData, ProviderAccount, ProviderAccountId,
+    ProviderAccountStore, QuotaAccessChange, QuotaEvidence, QuotaObservation, QuotaState,
 };
 use gateway_core::operation::{GenerateRequest, Operation, ProtocolPayload};
 use gateway_core::provider_ports::{
@@ -515,15 +513,14 @@ async fn openai_admin_provider_projects_official_codex_quota_and_independent_buc
             }
         }]
     });
+    let observed_at = SystemTime::now();
     store
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at,
+            state: QuotaState::observed_unknown(observed_at),
         })
         .await
         .expect("persist quota");
@@ -596,7 +593,7 @@ async fn openai_admin_provider_projects_official_codex_quota_and_independent_buc
 }
 
 #[tokio::test]
-async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutating_raw_usage() {
+async fn openai_admin_keeps_confirmed_exhaustion_separate_from_raw_usage_display() {
     let store = Arc::new(MemoryAccountStore::default());
     let account_id = "acct_admin_confirmed_exhaustion";
     store
@@ -611,11 +608,12 @@ async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutati
         .await;
     let account = store.account(account_id).expect("stored account");
     let reset_at = 1_900_000_000_u64;
+    let observed_at = SystemTime::now();
     store
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
+            quota: OpaqueProviderData::new(
                 json!({
                     "rate_limit": {
                         "allowed": true,
@@ -626,19 +624,17 @@ async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutati
                 .as_object()
                 .expect("quota object")
                 .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            ),
+            observed_at,
+            state: QuotaState::allowed(observed_at),
         })
         .await
         .expect("persist raw quota");
     store
-        .apply_state_change(AccountStateChange {
-            message: None,
+        .apply_quota_access(QuotaAccessChange {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            availability: CoreAccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
+            state: QuotaState::exhausted(QuotaEvidence::UsageLimitReached, SystemTime::now(), None),
         })
         .await
         .expect("mark account exhausted");
@@ -661,7 +657,7 @@ async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutati
         .expect("project exhausted quota");
 
     assert_eq!(exhausted.windows.len(), 1);
-    assert_eq!(exhausted.windows[0].used_percent, Some(100.0));
+    assert_eq!(exhausted.windows[0].used_percent, Some(86.0));
     let raw = store
         .get_quotas(std::slice::from_ref(account.id()))
         .await
@@ -669,17 +665,15 @@ async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutati
         .pop()
         .expect("raw quota");
     assert_eq!(
-        raw.quota.expect("raw document").expose_to_provider()["rate_limit"]["primary_window"]["used_percent"],
+        raw.quota.expose_to_provider()["rate_limit"]["primary_window"]["used_percent"],
         86
     );
 
     store
-        .apply_state_change(AccountStateChange {
-            message: None,
+        .apply_quota_access(QuotaAccessChange {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            availability: CoreAccountAvailability::Ready,
-            observed_at: SystemTime::now(),
+            state: QuotaState::allowed(SystemTime::now()),
         })
         .await
         .expect("recover account");
@@ -735,7 +729,7 @@ async fn openai_admin_provider_rejects_unprepared_mutations_before_store_commit(
     stale_record.access_token_expires_at = None;
     stale_record.next_refresh_at = None;
     stale_record.enabled = false;
-    stale_record.availability = AdminAccountAvailability::Banned;
+    stale_record.credential_state = CredentialState::Banned;
     let rotation_error = admin
         .prepare_rotation(PrepareCredentialRotation {
             account: stale_record,
@@ -801,10 +795,11 @@ fn account_record(account: &ProviderAccount) -> AccountRecord {
         access_token_expires_at: account.access_token_expires_at().map(DateTime::<Utc>::from),
         next_refresh_at: account.next_refresh_at().map(DateTime::<Utc>::from),
         enabled: account.enabled(),
-        availability: AdminAccountAvailability::Ready,
-        availability_observed_at: now,
+        credential_state: account.credential_state(),
+        credential_observed_at: now,
+        quota: account.quota(),
+        last_error_reason: account.last_error_reason(),
         last_error_message: None,
-        quota_observed_at: None,
         created_at: now,
         updated_at: now,
     }
diff --git a/backend/crates/providers/openai/tests/config.rs b/backend/crates/providers/openai/tests/config.rs
index ff7acf608..2f6b55605 100644
--- a/backend/crates/providers/openai/tests/config.rs
+++ b/backend/crates/providers/openai/tests/config.rs
@@ -82,14 +82,6 @@ fn openai_config_restricts_upstream_base_url_to_https_or_loopback_http() {
     }
 }
 
-#[test]
-fn openai_config_keeps_the_quota_exhaustion_scheduling_switch() {
-    let mut config = valid_config();
-    config.quota.skip_exhausted = false;
-
-    assert!(!config.quota_skip_exhausted());
-}
-
 #[test]
 fn openai_config_defaults_to_the_provider_owned_operating_values() {
     let config = OpenAiConfig::default();
@@ -104,7 +96,6 @@ fn openai_config_defaults_to_the_provider_owned_operating_values() {
             config.ws_pool.max_connecting,
             config.ws_pool.initial_event_timeout_ms,
             config.quota.refresh_interval_minutes,
-            config.quota.skip_exhausted,
             config.auth.refresh_enabled,
             config.auth.oauth_client_id.as_str(),
             config.auth.oauth_token_endpoint.as_str(),
@@ -119,7 +110,6 @@ fn openai_config_defaults_to_the_provider_owned_operating_values() {
             20_000,
             15,
             true,
-            true,
             "app_EMoamEEZ73f0CkXaXp7hrann",
             "https://auth.openai.com/oauth/token",
         )
diff --git a/backend/crates/providers/openai/tests/credential/agent_identity.rs b/backend/crates/providers/openai/tests/credential/agent_identity.rs
index 8146a314a..41bc81b5d 100644
--- a/backend/crates/providers/openai/tests/credential/agent_identity.rs
+++ b/backend/crates/providers/openai/tests/credential/agent_identity.rs
@@ -9,8 +9,8 @@ use chrono::{TimeZone, Utc};
 use ed25519_dalek::pkcs8::EncodePrivateKey as _;
 use ed25519_dalek::{Signature, SigningKey, Verifier as _};
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialRevision, NewProviderAccount, ProviderAccount,
-    ProviderAccountId, ProviderAccountStore,
+    CredentialRevision, CredentialState, NewProviderAccount, ProviderAccount, ProviderAccountId,
+    ProviderAccountStore, QuotaState,
 };
 use gateway_core::routing::ProviderKind;
 use provider_openai::credential::{
@@ -65,7 +65,13 @@ fn agent_account(
         Some("agent-account".to_owned()),
         Some("pro".to_owned()),
     )
-    .with_runtime_state(true, AccountAvailability::Ready)
+    .with_account_facts(
+        true,
+        CredentialState::Ready,
+        QuotaState::unknown(),
+        None,
+        None,
+    )
     .with_refresh_schedule(false, None);
     NewProviderAccount {
         account,
diff --git a/backend/crates/providers/openai/tests/credential/contract.rs b/backend/crates/providers/openai/tests/credential/contract.rs
index 0aec695b8..823ddde5b 100644
--- a/backend/crates/providers/openai/tests/credential/contract.rs
+++ b/backend/crates/providers/openai/tests/credential/contract.rs
@@ -8,9 +8,10 @@ use gateway_core::engine::continuation::{
     ContinuationBinding, NativeContinuationPin, PreviousResponseId,
 };
 use gateway_core::engine::credential::{
-    AccountAttemptFeedback, AccountAvailability, AccountFeedbackStats, AccountSelectionPolicy,
-    AccountStateChange, OpaqueProviderData, ProviderAccountId, ProviderAccountStore as _,
-    QuotaObservation, QuotaWriteOutcome, RotationStrategy,
+    AccountAttemptFeedback, AccountErrorReason, AccountFeedbackStats, AccountSelectionPolicy,
+    AccountStateChange, CredentialState, OpaqueProviderData, ProviderAccount, ProviderAccountId,
+    ProviderAccountStore as _, QuotaAccessChange, QuotaAccessState, QuotaEvidence,
+    QuotaObservation, QuotaState, QuotaWriteOutcome, RotationStrategy,
 };
 use gateway_core::engine::{
     AccountAttemptContext, AttemptContext, CancellationToken, ModelRequestId, RequestAttemptContext,
@@ -105,7 +106,6 @@ fn selector_with_affinity(
         leases,
         session_affinity,
         Arc::new(AccountFeedbackStats::default()),
-        true,
         Arc::new(MemoryCooldownPort::new()),
     )
 }
@@ -115,7 +115,6 @@ fn selector_with_runtime(
     leases: Arc<TestLeaseCoordinator>,
     session_affinity: Arc<MemorySessionAffinity>,
     account_feedback: Arc<AccountFeedbackStats>,
-    skip_exhausted: bool,
     cooldowns: Arc<dyn ProviderCooldownPort>,
 ) -> CodexCredentialSelector {
     let profile = CodexWireProfileState::new(CodexWireProfile {
@@ -158,10 +157,42 @@ fn selector_with_runtime(
         agent_identity,
         account_feedback,
         CodexCookiePolicy::official().expect("official cookie policy"),
-        skip_exhausted,
     )
 }
 
+fn persist_credential_state(
+    store: &MemoryAccountStore,
+    account: &ProviderAccount,
+    credential_state: CredentialState,
+) {
+    block_on(store.apply_state_change(AccountStateChange {
+        account_id: account.id().clone(),
+        expected_revision: account.revision(),
+        credential_state,
+        observed_at: SystemTime::now(),
+        error_reason: credential_state.error_reason(),
+        message: None,
+    }))
+    .expect("persist credential state");
+}
+
+fn persist_quota_exhaustion(
+    store: &MemoryAccountStore,
+    account: &ProviderAccount,
+    reset_at: Option<SystemTime>,
+) {
+    block_on(store.apply_quota_access(QuotaAccessChange {
+        account_id: account.id().clone(),
+        expected_revision: account.revision(),
+        state: QuotaState::exhausted(
+            QuotaEvidence::UsageLimitReached,
+            SystemTime::now(),
+            reset_at,
+        ),
+    }))
+    .expect("persist quota exhaustion");
+}
+
 #[test]
 fn codec_persists_tokens_as_plaintext_provider_json() {
     let encoded = CodexCredentialCodec::encode_new(
@@ -485,7 +516,6 @@ async fn selector_should_keep_a_schedulable_affinity_account_despite_soft_health
         Arc::new(TestLeaseCoordinator::default()),
         affinity,
         Arc::clone(&account_feedback),
-        true,
         Arc::new(MemoryCooldownPort::new()),
     );
     for _ in 0..4 {
@@ -528,16 +558,7 @@ async fn selector_should_escape_a_quota_exhausted_affinity_account() {
     create_account(&store, "acct_first", "at-first");
     create_account(&store, "acct_second", "at-second");
     let first = store.account("acct_first").expect("first account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: first.id().clone(),
-            expected_revision: first.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark first account exhausted");
+    persist_quota_exhaustion(&store, &first, None);
     let affinity = Arc::new(MemorySessionAffinity::default());
     let provider = ProviderKind::new("openai").expect("provider");
     let key = ProviderSessionAffinityKey::try_new("quota-session").expect("affinity key");
@@ -697,13 +718,15 @@ fn credential_expired_failure_marks_unified_account_expired() {
         store
             .account("acct_primary")
             .expect("account")
-            .availability(),
-        AccountAvailability::Expired
+            .credential_state(),
+        CredentialState::Expired
     );
+    let account = store.account("acct_primary").expect("expired account");
     assert_eq!(
-        store.last_error_message("acct_primary").as_deref(),
-        Some("upstream_credential_expired")
+        account.last_error_reason(),
+        Some(AccountErrorReason::AccessTokenExpired)
     );
+    assert_eq!(account.last_error_message(), None);
 }
 
 #[test]
@@ -734,13 +757,13 @@ fn credential_expired_failure_keeps_expired_oauth_for_bounded_refresh_recovery()
         store
             .account("acct_primary")
             .expect("account retained for refresh")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
 }
 
 #[test]
-fn rate_limited_failure_records_quota_window_without_changing_availability() {
+fn rate_limited_failure_records_runtime_cooldown_without_changing_persisted_facts() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_primary", "at-primary");
     let cooldowns = Arc::new(MemoryCooldownPort::new());
@@ -749,7 +772,6 @@ fn rate_limited_failure_records_quota_window_without_changing_availability() {
         Arc::new(TestLeaseCoordinator::default()),
         Arc::new(MemorySessionAffinity::default()),
         Arc::new(AccountFeedbackStats::default()),
-        true,
         Arc::clone(&cooldowns) as Arc<dyn ProviderCooldownPort>,
     );
     let attempt = attempt(BTreeSet::new());
@@ -774,10 +796,9 @@ fn rate_limited_failure_records_quota_window_without_changing_availability() {
     ))
     .expect("record rate-limit failure");
 
-    // 429 不改变 availability（限流不改变账号可用性），也不污染 quota JSON——
-    // 临时限流写入 Redis 冷却（到期自动解除），额度重置时间保持不变。
     let account = store.account("acct_primary").expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
+    assert_eq!(account.quota().access(), QuotaAccessState::Unknown);
     assert!(
         store.quota_json("acct_primary").is_none(),
         "429 must not synthesize quota window"
@@ -800,7 +821,7 @@ async fn usage_limit_exhaustion_marks_quota_exhausted_without_usage_probe() {
         .record_failure(
             &account,
             CodexAccountFailure::UsageLimitExhausted {
-                retry_after: Some(Duration::from_secs(30)),
+                reset_at: Some(SystemTime::now() + Duration::from_secs(30)),
             },
             None,
         )
@@ -808,7 +829,11 @@ async fn usage_limit_exhaustion_marks_quota_exhausted_without_usage_probe() {
         .expect("record usage-limit exhaustion");
 
     let account = store.account("acct_primary").expect("persisted account");
-    assert_eq!(account.availability(), AccountAvailability::QuotaExhausted);
+    assert_eq!(account.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(
+        account.quota().evidence(),
+        Some(QuotaEvidence::UsageLimitReached)
+    );
     assert_eq!(store.quota_reads(), 0);
 }
 
@@ -817,14 +842,7 @@ fn rate_limited_failure_does_not_downgrade_persisted_quota_exhaustion() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_primary", "at-primary");
     let account = store.account("acct_primary").expect("account");
-    block_on(store.apply_state_change(AccountStateChange {
-        message: None,
-        account_id: account.id().clone(),
-        expected_revision: account.revision(),
-        availability: AccountAvailability::QuotaExhausted,
-        observed_at: SystemTime::now(),
-    }))
-    .expect("mark exhausted");
+    persist_quota_exhaustion(&store, &account, None);
     let selector = selector(&store, Arc::new(TestLeaseCoordinator::default()));
 
     block_on(selector.record_failure(
@@ -836,13 +854,13 @@ fn rate_limited_failure_does_not_downgrade_persisted_quota_exhaustion() {
     ))
     .expect("record rate-limit failure");
 
-    // 429 不写 availability，402 的 QuotaExhausted 保持不变。
     assert_eq!(
         store
             .account("acct_primary")
             .expect("persisted account")
-            .availability(),
-        AccountAvailability::QuotaExhausted
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted
     );
 }
 
@@ -857,7 +875,6 @@ fn rate_limited_failure_does_not_consult_stale_quota_snapshot() {
         Arc::new(TestLeaseCoordinator::default()),
         Arc::new(MemorySessionAffinity::default()),
         Arc::new(AccountFeedbackStats::default()),
-        true,
         Arc::clone(&cooldowns) as Arc<dyn ProviderCooldownPort>,
     );
 
@@ -874,8 +891,8 @@ fn rate_limited_failure_does_not_consult_stale_quota_snapshot() {
         store
             .account("acct_primary")
             .expect("persisted account")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
     // 429 临时限流写入 Redis 冷却，不读写 quota JSON。
     assert_eq!(store.quota_reads(), 0);
@@ -891,14 +908,7 @@ fn rate_limited_failure_does_not_overwrite_stale_authentication_state() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_primary", "at-primary");
     let account = store.account("acct_primary").expect("account");
-    block_on(store.apply_state_change(AccountStateChange {
-        message: None,
-        account_id: account.id().clone(),
-        expected_revision: account.revision(),
-        availability: AccountAvailability::Invalid,
-        observed_at: SystemTime::now(),
-    }))
-    .expect("mark account invalid");
+    persist_credential_state(&store, &account, CredentialState::Invalid);
     let current = store.account("acct_primary").expect("invalid account");
     let selector = selector(&store, Arc::new(TestLeaseCoordinator::default()));
 
@@ -911,34 +921,26 @@ fn rate_limited_failure_does_not_overwrite_stale_authentication_state() {
     ))
     .expect("record rate-limit failure");
 
-    // 429 不写 availability（限流不改变账号可用性），认证终态保持不变。
     assert_eq!(
         store
             .account("acct_primary")
             .expect("persisted account")
-            .availability(),
-        AccountAvailability::Invalid
+            .credential_state(),
+        CredentialState::Invalid
     );
 }
 
 #[test]
 fn successful_upstream_response_recovers_non_quota_terminal_states() {
     for stale in [
-        AccountAvailability::Expired,
-        AccountAvailability::Invalid,
-        AccountAvailability::Banned,
+        CredentialState::Expired,
+        CredentialState::Invalid,
+        CredentialState::Banned,
     ] {
         let store = Arc::new(MemoryAccountStore::default());
         create_account(&store, "acct_primary", "at-primary");
         let account = store.account("acct_primary").expect("account");
-        block_on(store.apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: stale,
-            observed_at: SystemTime::now(),
-        }))
-        .expect("seed stale state");
+        persist_credential_state(&store, &account, stale);
         let current = store.account("acct_primary").expect("stale account");
         let selector = selector(&store, Arc::new(TestLeaseCoordinator::default()));
 
@@ -948,13 +950,34 @@ fn successful_upstream_response_recovers_non_quota_terminal_states() {
             store
                 .account("acct_primary")
                 .expect("recovered account")
-                .availability(),
-            AccountAvailability::Ready,
+                .credential_state(),
+            CredentialState::Ready,
             "stale state {stale:?}",
         );
     }
 }
 
+#[test]
+fn elapsed_quota_reset_remains_blocked_until_authoritative_recovery() {
+    let store = Arc::new(MemoryAccountStore::default());
+    create_account(&store, "acct_primary", "at-primary");
+    let account = store.account("acct_primary").expect("account");
+    persist_quota_exhaustion(
+        &store,
+        &account,
+        Some(SystemTime::now() - Duration::from_secs(1)),
+    );
+    let blocked = store.account("acct_primary").expect("blocked account");
+    assert!(blocked.quota().is_exhausted());
+    assert_eq!(
+        blocked
+            .status_projection(SystemTime::now(), None)
+            .status
+            .as_str(),
+        "quota_exhausted"
+    );
+}
+
 #[test]
 fn rate_limited_failures_for_distinct_accounts_do_not_conflict() {
     let store = Arc::new(MemoryAccountStore::default());
@@ -990,52 +1013,13 @@ fn rate_limited_failures_for_distinct_accounts_do_not_conflict() {
             store
                 .account("acct_first")
                 .expect("persisted first account")
-                .availability(),
+                .credential_state(),
             store
                 .account("acct_second")
                 .expect("persisted second account")
-                .availability(),
+                .credential_state(),
         ],
-        [AccountAvailability::Ready; 2]
-    );
-}
-
-#[test]
-fn selector_keeps_a_quota_exhausted_account_eligible_when_configured_not_to_skip_it() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_primary", "at-primary");
-    let strict_selector = selector(&store, Arc::new(TestLeaseCoordinator::default()));
-    let account = store.account("acct_primary").expect("account");
-    block_on(strict_selector.record_failure(&account, CodexAccountFailure::QuotaExhausted, None))
-        .expect("mark account exhausted");
-
-    let selector = selector_with_runtime(
-        &store,
-        Arc::new(TestLeaseCoordinator::default()),
-        Arc::new(MemorySessionAffinity::default()),
-        Arc::new(AccountFeedbackStats::default()),
-        false,
-        Arc::new(MemoryCooldownPort::new()),
-    );
-    let request_url =
-        Url::parse("https://chatgpt.com/backend-api/codex/responses").expect("request URL");
-    let request_attempt = attempt(BTreeSet::new());
-
-    let lease = block_on(selector.select(&SelectCodexCredential {
-        upstream_model: "gpt-5.4",
-        request_url: &request_url,
-        attempt: &request_attempt,
-        session_affinity_key: None,
-    }))
-    .expect("select quota exhausted account when skipping is disabled");
-
-    assert_eq!(lease.account_id().as_str(), "acct_primary");
-    assert_eq!(
-        store
-            .account("acct_primary")
-            .expect("persisted account")
-            .availability(),
-        AccountAvailability::QuotaExhausted
+        [CredentialState::Ready; 2]
     );
 }
 
@@ -1054,7 +1038,6 @@ fn native_continuation_surfaces_the_original_accounts_quota_status_to_the_coordi
         Arc::new(TestLeaseCoordinator::default()),
         Arc::new(MemorySessionAffinity::default()),
         Arc::new(AccountFeedbackStats::default()),
-        false,
         Arc::new(MemoryCooldownPort::new()),
     );
     let continuation = NativeContinuationPin::new(
@@ -1108,14 +1091,13 @@ fn native_continuation_surfaces_the_original_accounts_quota_signal_to_the_coordi
             "primary_window": {"used_percent": 98}
         }
     });
+    let observed_at = SystemTime::now();
     let outcome = block_on(store.compare_and_swap_quota(QuotaObservation {
         account_id: original.id().clone(),
         expected_revision: original.revision(),
-        quota: Some(OpaqueProviderData::new(
-            quota.as_object().expect("quota object").clone(),
-        )),
-        observed_at: Some(SystemTime::now()),
-        limit_reached: None,
+        quota: OpaqueProviderData::new(quota.as_object().expect("quota object").clone()),
+        observed_at,
+        state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
     }))
     .expect("persist quota signal");
     assert!(matches!(outcome, QuotaWriteOutcome::Updated));
@@ -1125,7 +1107,6 @@ fn native_continuation_surfaces_the_original_accounts_quota_signal_to_the_coordi
         Arc::new(TestLeaseCoordinator::default()),
         Arc::new(MemorySessionAffinity::default()),
         Arc::new(AccountFeedbackStats::default()),
-        false,
         Arc::new(MemoryCooldownPort::new()),
     );
     let continuation = NativeContinuationPin::new(
@@ -1194,8 +1175,8 @@ fn identity_verification_failure_isolates_only_selected_account() {
         store
             .account(lease.account_id().as_str())
             .expect("selected account")
-            .availability(),
-        AccountAvailability::Invalid
+            .credential_state(),
+        CredentialState::Invalid
     );
     let other = if lease.account_id().as_str() == "acct_primary" {
         "acct_other"
@@ -1203,13 +1184,16 @@ fn identity_verification_failure_isolates_only_selected_account() {
         "acct_primary"
     };
     assert_eq!(
-        store.account(other).expect("other account").availability(),
-        AccountAvailability::Ready
+        store
+            .account(other)
+            .expect("other account")
+            .credential_state(),
+        CredentialState::Ready
     );
 }
 
 #[test]
-fn cloudflare_challenge_does_not_change_availability() {
+fn cloudflare_challenge_does_not_change_persisted_account_facts() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_primary", "at-primary");
     let selector = selector(&store, Arc::new(TestLeaseCoordinator::default()));
@@ -1226,7 +1210,6 @@ fn cloudflare_challenge_does_not_change_availability() {
         )
         .expect("select account");
 
-    // Cloudflare 挑战只走内存退避表，不写 availability（限流不改变账号可用性）。
     block_on(selector.record_failure(
         lease.account(),
         CodexAccountFailure::CloudflareChallenge { retry_after: None },
@@ -1238,8 +1221,8 @@ fn cloudflare_challenge_does_not_change_availability() {
         store
             .account("acct_primary")
             .expect("account")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
     block_on(selector.record_success(lease.account(), None));
 }
@@ -1279,15 +1262,15 @@ fn repeated_cloudflare_path_block_marks_only_the_affected_account_invalid() {
         store
             .account("acct_primary")
             .expect("affected account")
-            .availability(),
-        AccountAvailability::Invalid
+            .credential_state(),
+        CredentialState::Invalid
     );
     assert_eq!(
         store
             .account("acct_other")
             .expect("other account")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
 }
 
@@ -1416,7 +1399,8 @@ fn response_cookie_rotation_returns_a_current_account_for_later_fenced_writes()
         store
             .account("acct_primary")
             .expect("updated account")
-            .availability(),
-        AccountAvailability::QuotaExhausted
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted
     );
 }
diff --git a/backend/crates/providers/openai/tests/credential/oauth.rs b/backend/crates/providers/openai/tests/credential/oauth.rs
index 128ec2c0f..6d8ac7de2 100644
--- a/backend/crates/providers/openai/tests/credential/oauth.rs
+++ b/backend/crates/providers/openai/tests/credential/oauth.rs
@@ -7,6 +7,7 @@ use gateway_admin::model::provider_credentials::{
     AuthorizationMutationTarget, AuthorizationOwnerBinding, PendingAuthorizationMutation,
 };
 use gateway_admin::model::{MutationActor, MutationContext};
+use gateway_core::engine::credential::AccountStatus;
 use gateway_core::routing::ProviderKind;
 use provider_openai::credential::token_client::{
     AuthorizationCodeExchangeError, AuthorizationCodeExchanger, AuthorizationCodeGrant,
@@ -182,7 +183,13 @@ async fn first_exchange_uses_official_id_token_claim_mapping_without_signature_v
     assert_eq!(account.account.upstream_user_id(), Some("chatgpt-user"));
     assert_eq!(account.account.upstream_account_id(), Some("workspace-id"));
     assert_eq!(account.account.plan_type(), Some("pro"));
-    assert!(account.account.is_schedulable(SystemTime::now()));
+    assert_eq!(
+        account
+            .account
+            .status_projection(SystemTime::now(), None)
+            .status,
+        AccountStatus::Normal
+    );
     assert!(
         account.account.next_refresh_at().is_none(),
         "normal OAuth creation must not persist a margin-derived refresh time"
@@ -201,7 +208,13 @@ async fn first_exchange_permits_missing_identity_claims_but_requires_a_parseable
     };
     assert_eq!(account.account.email(), Some("profile@example.com"));
     assert_eq!(account.account.upstream_user_id(), None);
-    assert!(!account.account.is_schedulable(SystemTime::now()));
+    assert_eq!(
+        account
+            .account
+            .status_projection(SystemTime::now(), None)
+            .status,
+        AccountStatus::Error
+    );
 
     let error = complete("header.not-base64.signature".to_owned())
         .await
diff --git a/backend/crates/providers/openai/tests/credential/quota/mod.rs b/backend/crates/providers/openai/tests/credential/quota/mod.rs
index a835223a0..453c4a88a 100644
--- a/backend/crates/providers/openai/tests/credential/quota/mod.rs
+++ b/backend/crates/providers/openai/tests/credential/quota/mod.rs
@@ -1,7 +1,4 @@
-//! quota 测试入口与共享 fixture。
-//!
-//! - [`snapshot`]：快照聚合、窗口滚动与调度信号回归。
-//! - [`recovery`]：402 恢复证据回归。
+//! OpenAI 额度事实边界与展示快照回归。
 
 mod recovery;
 mod snapshot;
@@ -11,16 +8,15 @@ use std::time::{Duration, SystemTime};
 
 use chrono::{TimeZone as _, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, OpaqueProviderData, ProviderAccountStore as _,
-    QuotaObservation,
+    AccountStateChange, AccountStatus, CredentialState, ProviderAccount, ProviderAccountStore as _,
+    QuotaAccessChange, QuotaAccessState, QuotaEvidence, QuotaState,
 };
 use provider_openai::OFFICIAL_CODEX_BASE_URL;
 use provider_openai::credential::{
-    CodexCredentialQuotaError, CodexCredentialQuotaService, CodexQuotaSyncSummary,
-    CodexQuotaWindowKind, ImportCodexOAuthCredential,
+    CodexCredentialQuotaError, CodexCredentialQuotaService, ImportCodexOAuthCredential,
 };
 use provider_openai::transport::profile::{CodexWireProfile, CodexWireProfileState};
-use serde_json::{Value, json};
+use serde_json::json;
 use wiremock::matchers::{header, method, path};
 use wiremock::{Mock, MockServer, ResponseTemplate};
 
@@ -44,22 +40,16 @@ fn wire_profile() -> CodexWireProfileState {
 }
 
 fn quota_service(store: &Arc<MemoryAccountStore>) -> CodexCredentialQuotaService {
-    quota_service_with_http(
+    quota_service_with_base_url(
         store,
         reqwest::Client::builder()
             .no_proxy()
             .build()
             .expect("client"),
+        OFFICIAL_CODEX_BASE_URL.to_owned(),
     )
 }
 
-fn quota_service_with_http(
-    store: &Arc<MemoryAccountStore>,
-    http: reqwest::Client,
-) -> CodexCredentialQuotaService {
-    quota_service_with_base_url(store, http, OFFICIAL_CODEX_BASE_URL.to_owned())
-}
-
 fn quota_service_with_base_url(
     store: &Arc<MemoryAccountStore>,
     http: reqwest::Client,
@@ -75,17 +65,6 @@ fn quota_service_with_base_url(
     )
 }
 
-fn blocked_network_quota_service(store: &Arc<MemoryAccountStore>) -> CodexCredentialQuotaService {
-    let proxy = reqwest::Proxy::all("http://127.0.0.1:9").expect("loopback proxy");
-    let http = reqwest::Client::builder()
-        .proxy(proxy)
-        .connect_timeout(Duration::from_secs(1))
-        .timeout(Duration::from_secs(1))
-        .build()
-        .expect("blocked client");
-    quota_service_with_http(store, http)
-}
-
 async fn create_account(store: &Arc<MemoryAccountStore>, account_id: &str) {
     create_account_with_enabled(store, account_id, true).await;
 }
@@ -107,21 +86,58 @@ async fn create_account_with_enabled(
         .await;
 }
 
+async fn persist_credential_state(
+    store: &MemoryAccountStore,
+    account: &ProviderAccount,
+    credential_state: CredentialState,
+) {
+    store
+        .apply_state_change(AccountStateChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            credential_state,
+            observed_at: SystemTime::now(),
+            error_reason: credential_state.error_reason(),
+            message: None,
+        })
+        .await
+        .expect("persist credential state");
+}
+
+async fn persist_quota_state(
+    store: &MemoryAccountStore,
+    account: &ProviderAccount,
+    state: QuotaState,
+) {
+    store
+        .apply_quota_access(QuotaAccessChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            state,
+        })
+        .await
+        .expect("persist quota state");
+}
+
+fn exhausted_quota(reset_at: Option<SystemTime>) -> QuotaState {
+    QuotaState::exhausted(
+        QuotaEvidence::UsageLimitReached,
+        SystemTime::now(),
+        reset_at,
+    )
+}
+
 #[tokio::test]
-async fn passive_rate_limit_headers_update_quota_with_revision_fence() {
+async fn successful_inference_headers_are_authoritative_even_at_full_display_usage() {
     let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_quota").await;
-    let account = store.account("acct_passive_quota").expect("account");
+    let account_id = "acct_passive_allowed";
+    create_account(&store, account_id).await;
+    let account = store.account(account_id).expect("account");
+    persist_quota_state(&store, &account, exhausted_quota(None)).await;
     let service = quota_service(&store);
-    let reset_at = 1_900_000_000_i64;
     let headers = vec![
         ("x-codex-active-limit".to_owned(), "codex".to_owned()),
         ("x-codex-primary-used-percent".to_owned(), "100".to_owned()),
-        (
-            "x-codex-primary-window-minutes".to_owned(),
-            "300".to_owned(),
-        ),
-        ("x-codex-primary-reset-at".to_owned(), reset_at.to_string()),
         ("x-codex-limit-reached".to_owned(), "true".to_owned()),
     ];
 
@@ -131,1598 +147,39 @@ async fn passive_rate_limit_headers_update_quota_with_revision_fence() {
             .await
             .expect("passive quota")
     );
-    let current = store
-        .account("acct_passive_quota")
-        .expect("current account");
-    // 被动头限流只写 quota，不改变 availability（限流不改变账号可用性）。
-    assert_eq!(current.availability(), AccountAvailability::Ready);
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-    assert_eq!(snapshot.windows()[0].window_seconds(), Some(18_000));
-    assert_eq!(
-        snapshot.windows()[0]
-            .reset_at()
-            .map(|value| value.timestamp()),
-        Some(reset_at)
-    );
-}
-
-#[tokio::test]
-async fn passive_full_percent_with_explicit_allowance_keeps_account_ready() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_full_allowed").await;
-    let account = store.account("acct_passive_full_allowed").expect("account");
-    let service = quota_service(&store);
-    let headers = vec![
-        ("x-codex-active-limit".to_owned(), "codex".to_owned()),
-        ("x-codex-primary-used-percent".to_owned(), "100".to_owned()),
-        (
-            "x-codex-primary-reset-at".to_owned(),
-            "1900000000".to_owned(),
-        ),
-        ("x-codex-allowed".to_owned(), "true".to_owned()),
-        ("x-codex-limit-reached".to_owned(), "false".to_owned()),
-    ];
-
-    assert!(
-        service
-            .synchronize_passive_headers(&account, &headers)
-            .await
-            .expect("passive quota")
-    );
-    let current = store
-        .account("acct_passive_full_allowed")
-        .expect("current account");
+    let current = store.account(account_id).expect("updated account");
     let snapshot = service
         .read_account(account.id())
         .await
         .expect("read quota")
         .expect("quota snapshot");
 
-    assert_eq!(
-        (
-            current.availability(),
-            snapshot.fact().remaining_percent(),
-            snapshot.fact().exhausted(),
-        ),
-        // used=100 是快照级 exhaustion，但 availability 保持 Ready
-        // （限流不改变账号可用性）。
-        (AccountAvailability::Ready, Some(0), true)
-    );
-}
-
-#[tokio::test]
-async fn passive_headers_should_materialize_false_when_quota_is_not_exhausted() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_quota_available").await;
-    let account = store
-        .account("acct_passive_quota_available")
-        .expect("account");
-    let service = quota_service(&store);
-    let headers = vec![
-        ("x-codex-active-limit".to_owned(), "codex".to_owned()),
-        ("x-codex-primary-used-percent".to_owned(), "31".to_owned()),
-        ("x-codex-allowed".to_owned(), "true".to_owned()),
-        ("x-codex-limit-reached".to_owned(), "false".to_owned()),
-    ];
-
-    assert!(
-        service
-            .synchronize_passive_headers(&account, &headers)
-            .await
-            .expect("passive quota")
-    );
-
-    let observations = store
-        .get_quotas(std::slice::from_ref(account.id()))
-        .await
-        .expect("read quota observation");
-    assert_eq!(
-        observations
-            .first()
-            .and_then(|observation| observation.limit_reached),
-        Some(false)
-    );
-}
-
-#[tokio::test]
-async fn manual_quota_refresh_preserves_disabled_account_state() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_disabled_quota_state";
-    create_account_with_enabled(&store, account_id, false).await;
-    let account = store.account(account_id).expect("created disabled account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::Expired,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("seed disabled account state");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 20, "reset_at": 1_900_000_000}
-            }
-        })))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    service
-        .refresh_account(account.id())
-        .await
-        .expect("refresh disabled account quota");
-
-    let current = store
-        .account(account_id)
-        .expect("disabled account after quota refresh");
-    assert!(!current.enabled());
-    assert_eq!(current.availability(), AccountAvailability::Expired);
-    assert!(store.has_quota(account_id));
-}
-
-#[tokio::test]
-async fn manual_quota_unauthorized_rejection_preserves_current_availability() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_quota_auth_rejected";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(401))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    assert!(matches!(
-        service.refresh_account(account.id()).await,
-        Err(CodexCredentialQuotaError::Upstream { .. })
-    ));
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after rejection")
-            .availability(),
-        AccountAvailability::QuotaExhausted
-    );
-}
-
-#[tokio::test]
-async fn manual_quota_forbidden_rejection_preserves_current_availability() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_quota_forbidden";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(403))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    assert!(matches!(
-        service.refresh_account(account.id()).await,
-        Err(CodexCredentialQuotaError::Upstream { .. })
-    ));
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after rejection")
-            .availability(),
-        AccountAvailability::QuotaExhausted
-    );
-}
-
-#[tokio::test]
-async fn manual_quota_refresh_waits_for_expired_oauth_token_to_be_refreshed() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_quota_expired_token";
-    let mut expired_profile = profile(&format!("chatgpt-{account_id}"));
-    expired_profile.access_token_expires_at = Some(Utc::now() - chrono::Duration::minutes(1));
-    store
-        .seed_oauth_credential(ImportCodexOAuthCredential {
-            account_id: account_id.to_owned(),
-            name: account_id.to_owned(),
-            secret: secret(&format!("token-{account_id}")),
-            verified_account: expired_profile,
-            next_refresh_at: Some(Utc::now() - chrono::Duration::minutes(5)),
-            enabled: true,
-        })
-        .await;
-    let account = store.account(account_id).expect("created account");
-    let server = MockServer::start().await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    assert!(matches!(
-        service.refresh_account(account.id()).await,
-        Err(CodexCredentialQuotaError::CredentialRefreshRequired)
-    ));
-    assert!(
-        server
-            .received_requests()
-            .await
-            .expect("received requests")
-            .is_empty()
-    );
-}
-
-#[tokio::test]
-async fn passive_rate_limit_headers_replace_stale_secondary_window() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_quota_snapshot").await;
-    let account = store
-        .account("acct_passive_quota_snapshot")
-        .expect("account");
-    let baseline = json!({
-        "rate_limit": {
-            "primary_window": {
-                "used_percent": 91,
-                "reset_at": 1_900_000_000,
-                "limit_window_seconds": 2_592_000
-            },
-            "secondary_window": {
-                "used_percent": 43,
-                "reset_at": 1_900_000_000,
-                "limit_window_seconds": 2_592_000
-            }
-        }
-    });
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                baseline.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("persist baseline quota");
-    let service = quota_service(&store);
-    let headers = vec![
-        ("x-codex-active-limit".to_owned(), "codex".to_owned()),
-        ("x-codex-primary-used-percent".to_owned(), "92".to_owned()),
-        (
-            "x-codex-primary-window-minutes".to_owned(),
-            "43200".to_owned(),
-        ),
-        (
-            "x-codex-primary-reset-at".to_owned(),
-            "1900000000".to_owned(),
-        ),
-    ];
-
-    assert!(
-        service
-            .synchronize_passive_headers(&account, &headers)
-            .await
-            .expect("passive quota")
-    );
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-    let raw = store
-        .quota_json("acct_passive_quota_snapshot")
-        .expect("stored passive quota");
-    let monthly = snapshot
-        .windows()
-        .iter()
-        .filter(|window| window.kind() == CodexQuotaWindowKind::Monthly)
-        .collect::<Vec<_>>();
-
-    assert_eq!(snapshot.windows().len(), 1);
-    assert_eq!(monthly.len(), 1);
-    assert_eq!(monthly[0].used_percent(), Some(92.0));
-    assert!(
-        raw.pointer("/rate_limit/secondary_window").is_none(),
-        "a normal response without a secondary window must delete stale raw state"
-    );
-}
-
-#[tokio::test]
-async fn manual_quota_refresh_marks_ready_account_exhausted_and_drops_empty_secondary_window() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_secondary_placeholder";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": false,
-                "limit_reached": true,
-                "primary_window": {
-                    "used_percent": 100,
-                    "reset_at": 1_900_000_000,
-                    "limit_window_seconds": 2_592_000
-                },
-                "secondary_window": {
-                    "used_percent": 0,
-                    "limit_reached": false
-                }
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let snapshot = service
-        .refresh_account(account.id())
-        .await
-        .expect("manual quota refresh");
-
-    assert_eq!(snapshot.windows().len(), 1);
-    assert_eq!(snapshot.windows()[0].used_percent(), Some(100.0));
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after refresh")
-            .availability(),
-        AccountAvailability::QuotaExhausted
-    );
-}
-
-#[tokio::test]
-async fn manual_quota_refresh_drops_null_secondary_window_during_confirmed_exhaustion() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_null_secondary_placeholder";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    let reset_at = 1_900_000_000;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
-                        "primary_window": {
-                            "used_percent": 100,
-                            "reset_at": reset_at,
-                            "limit_window_seconds": 2_592_000
-                        }
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("seed confirmed exhaustion");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {
-                    "used_percent": 86,
-                    "reset_at": reset_at,
-                    "reset_after_seconds": 2_133_000,
-                    "limit_window_seconds": 2_592_000
-                },
-                "secondary_window": null
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let snapshot = service
-        .refresh_account(account.id())
-        .await
-        .expect("manual quota refresh");
-    let persisted = store
-        .get_quotas(&[account.id().clone()])
-        .await
-        .expect("read persisted quota")
-        .into_iter()
-        .next()
-        .and_then(|observation| observation.quota)
-        .map(OpaqueProviderData::into_inner)
-        .map(Value::Object)
-        .expect("persisted quota");
-
-    assert_eq!(snapshot.windows().len(), 1);
-    assert_eq!(snapshot.windows()[0].used_percent(), Some(100.0));
-    assert_eq!(
-        snapshot.windows()[0]
-            .reset_at()
-            .map(|value| value.timestamp()),
-        Some(reset_at)
-    );
-    assert!(snapshot.fact().exhausted());
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after refresh")
-            .availability(),
-        AccountAvailability::QuotaExhausted
-    );
-    assert!(
-        persisted.pointer("/rate_limit/secondary_window").is_none(),
-        "a null secondary window must not be projected as 100%"
-    );
-}
-
-#[tokio::test]
-async fn passive_active_limit_keeps_the_top_level_codex_bucket_canonical() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_active_limit").await;
-    let account = store.account("acct_passive_active_limit").expect("account");
-    let baseline = json!({
-        "additional_rate_limits": [{
-            "metered_feature": "codex",
-            "rate_limit": {
-                "allowed": true,
-                "primary_window": {
-                    "used_percent": 20,
-                    "reset_at": 1_900_000_000,
-                    "limit_window_seconds": 604_800
-                }
-            }
-        }]
-    });
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                baseline.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("persist baseline quota");
-    let service = quota_service(&store);
-    let headers = vec![
-        ("x-codex-active-limit".to_owned(), "premium".to_owned()),
-        ("x-premium-primary-used-percent".to_owned(), "55".to_owned()),
-        (
-            "x-premium-primary-window-minutes".to_owned(),
-            "10080".to_owned(),
-        ),
-        (
-            "x-premium-primary-reset-at".to_owned(),
-            "1900000000".to_owned(),
-        ),
-    ];
-
-    assert!(
-        service
-            .synchronize_passive_headers(&account, &headers)
-            .await
-            .expect("passive quota")
-    );
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-
-    assert_eq!(snapshot.windows().len(), 1);
-    assert!(
-        snapshot
-            .windows()
-            .iter()
-            .any(|window| { window.source() == "codex" && window.used_percent() == Some(55.0) })
-    );
-}
-
-#[tokio::test]
-async fn passive_metadata_headers_preserve_quota_observation_time() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_passive_metadata").await;
-    let account = store.account("acct_passive_metadata").expect("account");
-    let baseline = json!({
-        "rate_limit": {
-            "allowed": true,
-            "primary_window": {
-                "used_percent": 20,
-                "reset_at": 1_900_000_000,
-                "limit_window_seconds": 604_800
-            }
-        }
-    });
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                baseline.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("persist baseline quota");
-    let before = store
-        .get_quotas(std::slice::from_ref(account.id()))
-        .await
-        .expect("read baseline quota");
-    let service = quota_service(&store);
-    let headers = vec![
-        ("x-codex-plan-type".to_owned(), "free".to_owned()),
-        ("x-codex-credits-has-credits".to_owned(), "true".to_owned()),
-        ("x-codex-credits-unlimited".to_owned(), "false".to_owned()),
-    ];
-
-    assert!(
-        service
-            .synchronize_passive_headers(&account, &headers)
-            .await
-            .expect("metadata-only passive response")
-    );
-    let after = store
-        .get_quotas(std::slice::from_ref(account.id()))
-        .await
-        .expect("read updated quota metadata");
-
-    assert_eq!(after[0].observed_at, before[0].observed_at);
-    assert_eq!(after[0].limit_reached, before[0].limit_reached);
-    assert_eq!(
-        store
-            .quota_json("acct_passive_metadata")
-            .and_then(|quota| quota.get("plan_type").cloned()),
-        Some(json!("free"))
-    );
-}
-
-#[tokio::test]
-async fn synchronize_without_accounts_is_a_noop_before_network_io() {
-    let store = Arc::new(MemoryAccountStore::default());
-
-    let summary = quota_service(&store)
-        .synchronize()
-        .await
-        .expect("empty synchronization");
-
-    assert_eq!(summary.updated, 0);
-    assert_eq!(summary.exhausted, 0);
-    assert_eq!(summary.banned, 0);
-    assert_eq!(summary.transient, 0);
-    assert_eq!(summary.stale, 0);
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_does_not_scan_stale_ready_accounts() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_ready").await;
-    let account = store
-        .account("acct_periodic_ready")
-        .expect("created account");
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": true,
-                        "primary_window": {"used_percent": 10, "reset_at": 1_900_000_000}
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            // 正常账号即使缓存已旧，也只等待真实请求被动同步，不能被定时任务主动拉取。
-            observed_at: Some(SystemTime::UNIX_EPOCH),
-            limit_reached: None,
-        })
-        .await
-        .expect("persist stale quota");
-
-    let summary = blocked_network_quota_service(&store)
-        .synchronize()
-        .await
-        .expect("ready account must not query upstream");
-
-    assert_eq!(summary, CodexQuotaSyncSummary::default());
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_marks_ready_account_exhausted_when_primary_is_exhausted() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_stuck_cooldown").await;
-    let account = store
-        .account("acct_periodic_stuck_cooldown")
-        .expect("created account");
-    let reset_at = Utc::now().timestamp() + 24 * 60 * 60;
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::Ready,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account cooldown");
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "primary_window": {"used_percent": 100, "reset_at": reset_at}
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("persist exhausted quota");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": false,
-                "limit_reached": true,
-                "primary_window": {"used_percent": 100, "reset_at": reset_at}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-    service
-        .prepare_scheduling(std::slice::from_ref(&account))
-        .await;
-
-    let summary = service.synchronize().await.expect("quota synchronization");
-
-    assert_eq!(summary.exhausted, 1);
-    let reconciled = store
-        .account("acct_periodic_stuck_cooldown")
-        .expect("reconciled account");
-    assert_eq!(
-        reconciled.availability(),
-        AccountAvailability::QuotaExhausted
-    );
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_keeps_ready_when_only_secondary_window_is_exhausted() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_secondary_only").await;
-    let reset_at = Utc::now().timestamp() + 24 * 60 * 60;
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 5, "reset_at": reset_at},
-                "secondary_window": {"used_percent": 100, "reset_at": reset_at}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("quota synchronization");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(
-        store
-            .account("acct_periodic_secondary_only")
-            .expect("reconciled account")
-            .availability(),
-        AccountAvailability::Ready
-    );
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_keeps_ready_when_primary_is_full_but_requests_are_allowed()
-{
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_primary_full_but_allowed").await;
-    let reset_at = Utc::now().timestamp() + 24 * 60 * 60;
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 100, "reset_at": reset_at}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("quota synchronization");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(
-        store
-            .account("acct_periodic_primary_full_but_allowed")
-            .expect("reconciled account")
-            .availability(),
-        AccountAvailability::Ready
-    );
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_keeps_ready_without_primary_exhaustion_evidence() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(
-        &store,
-        "acct_periodic_disallowed_without_primary_exhaustion",
-    )
-    .await;
-    let reset_at = Utc::now().timestamp() + 24 * 60 * 60;
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": false,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 5, "reset_at": reset_at}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("quota synchronization");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(
-        store
-            .account("acct_periodic_disallowed_without_primary_exhaustion")
-            .expect("reconciled account")
-            .availability(),
-        AccountAvailability::Ready
-    );
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_does_not_downgrade_exhaustion_on_rate_limit() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_exhausted").await;
-    let account = store
-        .account("acct_periodic_exhausted")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(429))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    service.synchronize().await.expect("quota synchronization");
-
-    let account = store
-        .account("acct_periodic_exhausted")
-        .expect("persisted account");
-    assert_eq!(account.availability(), AccountAvailability::QuotaExhausted);
-}
-
-#[tokio::test]
-async fn periodic_quota_refresh_drops_empty_secondary_window() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_secondary_placeholder";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {
-                    "used_percent": 99,
-                    "reset_at": 1_900_000_000,
-                    "limit_window_seconds": 2_592_000
-                },
-                "secondary_window": {}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("periodic quota refresh");
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(snapshot.windows().len(), 1);
-    assert_eq!(snapshot.windows()[0].used_percent(), Some(100.0));
-}
-
-#[tokio::test]
-async fn periodic_quota_refresh_drops_null_secondary_window() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_null_secondary_placeholder";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {
-                    "used_percent": 86,
-                    "reset_at": 1_900_000_000,
-                    "reset_after_seconds": 2_133_000,
-                    "limit_window_seconds": 2_592_000
-                },
-                "secondary_window": null
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("periodic quota refresh");
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(snapshot.windows().len(), 1);
-    assert_eq!(snapshot.windows()[0].used_percent(), Some(100.0));
-}
-
-#[tokio::test]
-async fn periodic_quota_refresh_keeps_nonempty_secondary_window_during_confirmed_exhaustion() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_real_secondary";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let secondary_reset_at = 1_900_604_800;
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {
-                    "used_percent": 99,
-                    "reset_at": 1_900_000_000,
-                    "limit_window_seconds": 2_592_000
-                },
-                "secondary_window": {
-                    "used_percent": 0,
-                    "reset_at": secondary_reset_at,
-                    "limit_window_seconds": 604_800
-                }
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let summary = service.synchronize().await.expect("periodic quota refresh");
-    let snapshot = service
-        .read_account(account.id())
-        .await
-        .expect("read quota")
-        .expect("quota snapshot");
-
-    assert_eq!(summary.exhausted, 1);
-    assert_eq!(snapshot.windows().len(), 2);
-    assert!(snapshot.windows().iter().any(|window| {
-        window.window_seconds() == Some(604_800)
-            && window.used_percent() == Some(100.0)
-            && window
-                .reset_at()
-                .is_some_and(|reset_at| reset_at.timestamp() == secondary_reset_at)
-    }));
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_respects_retry_after_on_service_unavailable() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_503_retry_after").await;
-    let account = store
-        .account("acct_periodic_503_retry_after")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        // 5xx 短退避重试后仍失败，Retry-After 用于写冷却，不再落入"未分类"。
-        .respond_with(ResponseTemplate::new(503).insert_header("Retry-After", "120"))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    service.synchronize().await.expect("quota synchronization");
-
-    let account = store
-        .account("acct_periodic_503_retry_after")
-        .expect("persisted account");
-    assert_eq!(account.availability(), AccountAvailability::QuotaExhausted);
-}
-
-#[tokio::test]
-async fn initial_quota_synchronization_retries_ready_accounts_without_observation() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_temporary_cooldown").await;
-    let account = store
-        .account("acct_periodic_temporary_cooldown")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::Ready,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account cooldown");
-
-    let summary = blocked_network_quota_service(&store)
-        .synchronize()
-        .await
-        .expect("initial quota sync must not fail the worker");
-
-    assert_eq!(summary.transient, 1);
-    assert_eq!(
-        store
-            .account("acct_periodic_temporary_cooldown")
-            .expect("cooldown account")
-            .availability(),
-        AccountAvailability::Ready
-    );
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_attempts_quota_exhausted_accounts() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_exhausted").await;
-    let account = store
-        .account("acct_periodic_exhausted")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-
-    let summary = blocked_network_quota_service(&store)
-        .synchronize()
-        .await
-        .expect("quota synchronization");
-
-    assert_eq!(summary.transient, 1);
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_rechecks_exhausted_accounts_without_waiting_for_reset() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_exhausted_cooldown").await;
-    let account = store
-        .account("acct_periodic_exhausted_cooldown")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted with a future reset");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(500))
-        // 5xx 短退避重试 1s/2s 后仍失败，最终计入 transient。
-        .expect(3)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    // reset 仅用于展示/调度状态，不能推迟额度耗尽账号的定时复核。
-    let due = service.synchronize().await.expect("quota synchronization");
-    let repeated = service
-        .synchronize()
-        .await
-        .expect("quota synchronization repeated");
-
-    assert_eq!(due.transient, 1);
-    assert_eq!(repeated, CodexQuotaSyncSummary::default());
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_keeps_exhaustion_at_ten_percent_after_advanced_reset() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_recovery_evidence";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    let reset_at = 1_900_000_000;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": true,
-                        "limit_reached": false,
-                        "primary_window": {"used_percent": 100, "reset_at": reset_at}
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("seed post-failure quota snapshot");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 100, "reset_at": reset_at}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let unchanged = service
-        .synchronize()
-        .await
-        .expect("unchanged quota recheck");
-
-    // used=100 是快照级 exhaustion，计 exhausted 而非 updated。
-    assert_eq!(unchanged.exhausted, 1);
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after unchanged snapshot")
-            .availability(),
-        AccountAvailability::QuotaExhausted
-    );
-
-    server.reset().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                // reset 已后移，但 10% 仍不能证明这是刚重置的新窗口。
-                "primary_window": {"used_percent": 10, "reset_at": reset_at + 3600}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    // 新 worker 实例模拟下一次 30 分钟复核，避免测试等待真实节流周期。
-    let next_cycle = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let ten_percent = next_cycle
-        .synchronize()
-        .await
-        .expect("ten-percent quota recheck");
-
-    assert_eq!(ten_percent.exhausted, 1);
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after ten-percent snapshot")
-            .availability(),
-        AccountAvailability::QuotaExhausted,
-        "an advanced reset at exactly 10% is not sufficient to release confirmed exhaustion"
-    );
-    let snapshot = next_cycle
-        .read_account(account.id())
-        .await
-        .expect("read held exhaustion projection")
-        .expect("held exhaustion projection");
     assert_eq!(snapshot.fact().remaining_percent(), Some(0));
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_recovers_with_advanced_reset_and_low_primary_usage() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_reset_elapsed";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    let old_reset = Utc::now().timestamp() + 3_600;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
-                        "primary_window": {"used_percent": 100, "reset_at": old_reset}
-                    }
-                })
-                .as_object()
-                .expect("recorded exhausted quota")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: Some(true),
-        })
-        .await
-        .expect("record future exhausted reset");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted with a future reset");
-    let server = MockServer::start().await;
-    let next_reset = old_reset + 3_600;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 1, "reset_at": next_reset}
-            }
-        })))
-        .expect(1)
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    // 定时复核可在旧 reset 前执行；新主窗口已推进且用量低于 10% 才释放额度耗尽状态。
-    let summary = service.synchronize().await.expect("quota synchronization");
-
-    assert_eq!(summary.updated, 1);
-    let current = store
-        .account(account_id)
-        .expect("account after elapsed reset");
-    assert_eq!(current.availability(), AccountAvailability::Ready);
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_throttles_the_same_exhausted_account() {
-    let store = Arc::new(MemoryAccountStore::default());
-    create_account(&store, "acct_periodic_throttled").await;
-    let account = store
-        .account("acct_periodic_throttled")
-        .expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
-    let service = blocked_network_quota_service(&store);
-
-    service.synchronize().await.expect("first quota cycle");
-    let summary = service.synchronize().await.expect("throttled quota cycle");
-
-    assert_eq!(summary, CodexQuotaSyncSummary::default());
-}
-
-#[tokio::test]
-async fn periodic_quota_synchronization_does_not_bypass_throttle_for_a_new_reset() {
-    let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_periodic_new_reset";
-    create_account(&store, account_id).await;
-    let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted with due reset");
-    let server = MockServer::start().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": false,
-                "limit_reached": true,
-                "primary_window": {"used_percent": 100, "reset_at": 2}
-            }
-        })))
-        .mount(&server)
-        .await;
-    let service = quota_service_with_base_url(
-        &store,
-        reqwest::Client::builder()
-            .no_proxy()
-            .build()
-            .expect("client"),
-        server.uri(),
-    );
-
-    let first = service.synchronize().await.expect("first reset recheck");
-    let second = service
-        .synchronize()
-        .await
-        .expect("throttled reset recheck");
-    let repeated = service.synchronize().await.expect("same reset throttled");
-    let request_count = server
-        .received_requests()
-        .await
-        .expect("received requests")
-        .len();
-
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Allowed);
+    assert_eq!(current.quota().access(), QuotaAccessState::Allowed);
     assert_eq!(
-        (first.exhausted, second.exhausted, repeated, request_count,),
-        (1, 0, CodexQuotaSyncSummary::default(), 1,)
+        current.status_projection(SystemTime::now(), None).status,
+        AccountStatus::Normal
     );
 }
 
 #[tokio::test]
-async fn invalid_quota_json_for_one_account_does_not_abort_the_batch() {
+async fn quota_refresh_persists_explicit_provider_denial() {
     let store = Arc::new(MemoryAccountStore::default());
-    for account_id in ["acct_quota_batch_bad", "acct_quota_batch_good"] {
-        create_account(&store, account_id).await;
-        let account = store.account(account_id).expect("created account");
-        store
-            .apply_state_change(AccountStateChange {
-                message: None,
-                account_id: account.id().clone(),
-                expected_revision: account.revision(),
-                availability: AccountAvailability::QuotaExhausted,
-                observed_at: SystemTime::now(),
-            })
-            .await
-            .expect("mark account exhausted");
-    }
-    let good = store
-        .account("acct_quota_batch_good")
-        .expect("good account");
-    let elapsed_reset = Utc::now().timestamp() - 60;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: good.id().clone(),
-            expected_revision: good.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
-                        "primary_window": {"used_percent": 100, "reset_at": elapsed_reset}
-                    }
-                })
-                .as_object()
-                .expect("recorded exhausted quota")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: Some(true),
-        })
-        .await
-        .expect("seed good account old reset");
+    let account_id = "acct_explicit_quota_denial";
+    create_account(&store, account_id).await;
+    let account = store.account(account_id).expect("account");
     let server = MockServer::start().await;
-    let next_reset = Utc::now().timestamp() + 3600;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .and(header("authorization", "Bearer token-acct_quota_batch_bad"))
-        .respond_with(
-            ResponseTemplate::new(200)
-                .set_body_json(json!({"rate_limit": {"allowed": "not-a-boolean"}})),
-        )
-        .mount(&server)
-        .await;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
         .and(header(
             "authorization",
-            "Bearer token-acct_quota_batch_good",
+            format!("Bearer token-{account_id}"),
         ))
         .respond_with(ResponseTemplate::new(200).set_body_json(json!({
             "rate_limit": {
-                "allowed": true,
-                "primary_window": {"used_percent": 1.0, "reset_at": next_reset}
+                "allowed": false,
+                "primary_window": {"used_percent": 8, "reset_at": 1_900_000_000}
             }
         })))
         .mount(&server)
@@ -1736,20 +193,125 @@ async fn invalid_quota_json_for_one_account_does_not_abort_the_batch() {
         server.uri(),
     );
 
-    let summary = service
-        .synchronize()
-        .await
-        .expect("batch must survive one invalid account");
-
-    assert_eq!(summary.updated, 1);
-    assert_eq!(summary.transient, 1);
-    let good = store
-        .account("acct_quota_batch_good")
-        .expect("good account");
     let snapshot = service
-        .read_account(good.id())
+        .refresh_account(account.id())
         .await
-        .expect("read good quota")
-        .expect("good quota persisted");
-    assert_eq!(snapshot.fact().remaining_percent(), Some(99));
+        .expect("refresh quota");
+    let current = store.account(account_id).expect("updated account");
+
+    assert_eq!(snapshot.fact().remaining_percent(), Some(92));
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(
+        snapshot.quota().evidence(),
+        Some(QuotaEvidence::ProviderDenied)
+    );
+    assert_eq!(
+        current.status_projection(SystemTime::now(), None).status,
+        AccountStatus::QuotaExhausted
+    );
+}
+
+#[tokio::test]
+async fn quota_endpoint_auth_rejections_do_not_reclassify_credentials_or_quota() {
+    for status in [401, 403, 429, 503] {
+        let store = Arc::new(MemoryAccountStore::default());
+        let account_id = format!("acct_quota_rejection_{status}");
+        create_account(&store, &account_id).await;
+        let account = store.account(&account_id).expect("account");
+        persist_quota_state(&store, &account, exhausted_quota(None)).await;
+        let server = MockServer::start().await;
+        Mock::given(method("GET"))
+            .and(path("/api/codex/usage"))
+            .respond_with(ResponseTemplate::new(status))
+            .mount(&server)
+            .await;
+        let service = quota_service_with_base_url(
+            &store,
+            reqwest::Client::builder()
+                .no_proxy()
+                .build()
+                .expect("client"),
+            server.uri(),
+        );
+
+        assert!(matches!(
+            service.refresh_account(account.id()).await,
+            Err(CodexCredentialQuotaError::Upstream { .. })
+        ));
+        let current = store.account(&account_id).expect("preserved account");
+        assert_eq!(current.credential_state(), CredentialState::Ready);
+        assert_eq!(current.quota().access(), QuotaAccessState::Exhausted);
+    }
+}
+
+#[tokio::test]
+async fn payment_required_is_authoritative_quota_exhaustion_without_fabricated_usage() {
+    let store = Arc::new(MemoryAccountStore::default());
+    let account_id = "acct_payment_required";
+    create_account(&store, account_id).await;
+    let account = store.account(account_id).expect("account");
+    let server = MockServer::start().await;
+    Mock::given(method("GET"))
+        .and(path("/api/codex/usage"))
+        .respond_with(ResponseTemplate::new(402).set_body_json(json!({
+            "detail": {"code": "billing_required"}
+        })))
+        .mount(&server)
+        .await;
+    let service = quota_service_with_base_url(
+        &store,
+        reqwest::Client::builder()
+            .no_proxy()
+            .build()
+            .expect("client"),
+        server.uri(),
+    );
+
+    assert!(service.refresh_account(account.id()).await.is_err());
+    let current = store.account(account_id).expect("updated account");
+    assert_eq!(current.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(
+        current.quota().evidence(),
+        Some(QuotaEvidence::PaymentRequired)
+    );
+    assert!(!store.has_quota(account_id));
+}
+
+#[tokio::test]
+async fn quota_refresh_preserves_disabled_and_credential_error_facts() {
+    let store = Arc::new(MemoryAccountStore::default());
+    let account_id = "acct_disabled_credential_error";
+    create_account_with_enabled(&store, account_id, false).await;
+    let account = store.account(account_id).expect("account");
+    persist_credential_state(&store, &account, CredentialState::Expired).await;
+    let server = MockServer::start().await;
+    Mock::given(method("GET"))
+        .and(path("/api/codex/usage"))
+        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
+            "rate_limit": {"allowed": true, "primary_window": {"used_percent": 1}}
+        })))
+        .mount(&server)
+        .await;
+    let service = quota_service_with_base_url(
+        &store,
+        reqwest::Client::builder()
+            .no_proxy()
+            .build()
+            .expect("client"),
+        server.uri(),
+    );
+
+    service
+        .refresh_account(account.id())
+        .await
+        .expect("refresh quota");
+    let current = store.account(account_id).expect("updated account");
+
+    assert!(!current.enabled());
+    assert_eq!(current.credential_state(), CredentialState::Expired);
+    assert_eq!(current.quota().access(), QuotaAccessState::Allowed);
+    assert_eq!(
+        current.status_projection(SystemTime::now(), None).status,
+        AccountStatus::Disabled
+    );
 }
diff --git a/backend/crates/providers/openai/tests/credential/quota/recovery.rs b/backend/crates/providers/openai/tests/credential/quota/recovery.rs
index 5e72bbe96..17a61f40c 100644
--- a/backend/crates/providers/openai/tests/credential/quota/recovery.rs
+++ b/backend/crates/providers/openai/tests/credential/quota/recovery.rs
@@ -1,25 +1,15 @@
-//! 402 恢复回归。
-//!
-//! 覆盖 `QuotaExhausted -> Ready` 的证据规则：新 core primary reset 后移 + 新快照用量低于 10%。
+//! 额度刷新与凭证事实相互独立的回归测试。
 
 use super::*;
 
 #[tokio::test]
-async fn manual_quota_refresh_keeps_confirmed_exhaustion_until_the_recorded_reset() {
+async fn quota_refresh_updates_access_fact_without_recovering_credential_error() {
     let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_manual_quota_state";
+    let account_id = "acct_independent_quota_and_credential";
     create_account(&store, account_id).await;
     let account = store.account(account_id).expect("created account");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::Expired,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("seed stale expired state");
+    persist_credential_state(&store, &account, CredentialState::Expired).await;
+
     let server = MockServer::start().await;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
@@ -45,20 +35,15 @@ async fn manual_quota_refresh_keeps_confirmed_exhaustion_until_the_recorded_rese
         server.uri(),
     );
 
-    let exhausted = service
+    let snapshot = service
         .refresh_account(account.id())
         .await
         .expect("refresh exhausted quota");
+    let current = store.account(account_id).expect("updated account");
 
-    assert!(exhausted.fact().exhausted());
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("exhausted account")
-            .availability(),
-        AccountAvailability::Expired,
-        "manual refresh never changes non-QuotaExhausted availability"
-    );
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(current.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(current.credential_state(), CredentialState::Expired);
 
     server.reset().await;
     Mock::given(method("GET"))
@@ -77,111 +62,39 @@ async fn manual_quota_refresh_keeps_confirmed_exhaustion_until_the_recorded_rese
         .mount(&server)
         .await;
 
-    let stale = service
+    let snapshot = service
         .refresh_account(account.id())
         .await
-        .expect("refresh contradictory full quota");
+        .expect("refresh allowed quota");
+    let current = store.account(account_id).expect("recovered quota account");
 
-    // used=100 是快照级 exhaustion。
-    assert!(stale.fact().exhausted());
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after contradictory quota")
-            .availability(),
-        AccountAvailability::Expired,
-        "an unchanged usage window cannot override an expired credential state"
-    );
-
-    server.reset().await;
-    Mock::given(method("GET"))
-        .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
-        .respond_with(ResponseTemplate::new(200).set_body_json(json!({
-            "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 99, "reset_at": 1_900_000_000}
-            }
-        })))
-        .mount(&server)
-        .await;
-
-    let unchanged_reset = service
-        .refresh_account(account.id())
-        .await
-        .expect("refresh lower usage quota");
-
-    assert!(!unchanged_reset.fact().exhausted());
-    assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after lower usage")
-            .availability(),
-        AccountAvailability::Expired,
-        "a lower used_percent before the recorded reset is not quota recovery for an expired credential"
-    );
+    assert_eq!(snapshot.fact().remaining_percent(), Some(0));
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Allowed);
+    assert_eq!(current.quota().access(), QuotaAccessState::Allowed);
+    assert_eq!(current.credential_state(), CredentialState::Expired);
 }
 
 #[tokio::test]
-async fn advanced_reset_with_primary_usage_below_ten_percent_recovers_ready() {
-    // 旧 reset 仍在未来；同一主窗口 reset 后移且用量低于 10% 时才恢复 Ready。
+async fn explicit_allowance_replaces_confirmed_exhaustion_without_usage_heuristics() {
     let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_cross_window_recovery";
+    let account_id = "acct_authoritative_quota_recovery";
     create_account(&store, account_id).await;
     let account = store.account(account_id).expect("created account");
-    let old_reset = Utc::now().timestamp() + 3_600;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
-                        "primary_window": {
-                            "used_percent": 100,
-                            "reset_at": old_reset,
-                            "limit_window_seconds": 3600
-                        }
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("seed old exhausted snapshot");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
+    persist_quota_state(
+        &store,
+        &account,
+        exhausted_quota(Some(SystemTime::now() + Duration::from_secs(3_600))),
+    )
+    .await;
+
     let server = MockServer::start().await;
-    let future_reset = old_reset + 3_600;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
         .respond_with(ResponseTemplate::new(200).set_body_json(json!({
             "rate_limit": {
                 "allowed": true,
                 "limit_reached": false,
-                "primary_window": {"used_percent": 9.9, "reset_at": future_reset}
+                "primary_window": {"used_percent": 100, "reset_at": 1_900_000_000}
             }
         })))
         .mount(&server)
@@ -195,77 +108,36 @@ async fn advanced_reset_with_primary_usage_below_ten_percent_recovers_ready() {
         server.uri(),
     );
 
-    let recovered = service
+    let snapshot = service
         .refresh_account(account.id())
         .await
-        .expect("refresh new window quota");
+        .expect("refresh authoritative allowance");
 
-    assert!(!recovered.fact().exhausted());
+    assert_eq!(snapshot.fact().remaining_percent(), Some(0));
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Allowed);
     assert_eq!(
         store
             .account(account_id)
-            .expect("account after cross-window recovery")
-            .availability(),
-        AccountAvailability::Ready,
-        "an advanced reset with a nearly unused primary window must recover QuotaExhausted"
+            .expect("updated account")
+            .quota()
+            .access(),
+        QuotaAccessState::Allowed
     );
 }
 
 #[tokio::test]
-async fn advanced_reset_with_primary_usage_at_ten_percent_keeps_confirmed_exhaustion() {
+async fn inconclusive_quota_refresh_preserves_confirmed_exhaustion() {
     let store = Arc::new(MemoryAccountStore::default());
-    let account_id = "acct_cross_window_ten_percent";
+    let account_id = "acct_inconclusive_quota_refresh";
     create_account(&store, account_id).await;
     let account = store.account(account_id).expect("created account");
-    let old_reset = Utc::now().timestamp() + 3_600;
-    store
-        .compare_and_swap_quota(QuotaObservation {
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                json!({
-                    "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
-                        "primary_window": {
-                            "used_percent": 100,
-                            "reset_at": old_reset,
-                            "limit_window_seconds": 3600
-                        }
-                    }
-                })
-                .as_object()
-                .expect("quota object")
-                .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
-        })
-        .await
-        .expect("seed old exhausted snapshot");
-    store
-        .apply_state_change(AccountStateChange {
-            message: None,
-            account_id: account.id().clone(),
-            expected_revision: account.revision(),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
-        })
-        .await
-        .expect("mark account exhausted");
+    persist_quota_state(&store, &account, exhausted_quota(None)).await;
     let server = MockServer::start().await;
-    let future_reset = old_reset + 3_600;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
         .respond_with(ResponseTemplate::new(200).set_body_json(json!({
             "rate_limit": {
-                "allowed": true,
-                "limit_reached": false,
-                "primary_window": {"used_percent": 10.0, "reset_at": future_reset}
+                "primary_window": {"used_percent": 12, "reset_at": 1_900_000_000}
             }
         })))
         .mount(&server)
@@ -279,24 +151,24 @@ async fn advanced_reset_with_primary_usage_at_ten_percent_keeps_confirmed_exhaus
         server.uri(),
     );
 
-    let held = service
+    let snapshot = service
         .refresh_account(account.id())
         .await
-        .expect("refresh non-empty new window quota");
+        .expect("refresh inconclusive quota");
 
-    assert!(held.fact().exhausted());
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Exhausted);
     assert_eq!(
         store
             .account(account_id)
-            .expect("account after ten-percent snapshot")
-            .availability(),
-        AccountAvailability::QuotaExhausted,
-        "a reset advance at exactly 10% must not release confirmed exhaustion"
+            .expect("preserved account")
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted
     );
 }
 
 #[tokio::test]
-async fn deactivated_workspace_quota_response_persists_the_upstream_reason() {
+async fn deactivated_workspace_quota_response_persists_credential_error_reason() {
     let store = Arc::new(MemoryAccountStore::default());
     let account_id = "acct_deactivated_workspace";
     create_account(&store, account_id).await;
@@ -304,10 +176,6 @@ async fn deactivated_workspace_quota_response_persists_the_upstream_reason() {
     let server = MockServer::start().await;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
-        .and(header(
-            "authorization",
-            format!("Bearer token-{account_id}"),
-        ))
         .respond_with(ResponseTemplate::new(402).set_body_json(json!({
             "detail": {
                 "code": "deactivated_workspace",
@@ -326,15 +194,12 @@ async fn deactivated_workspace_quota_response_persists_the_upstream_reason() {
     );
 
     assert!(service.refresh_account(account.id()).await.is_err());
+    let current = store
+        .account(account_id)
+        .expect("account after deactivation");
+    assert_eq!(current.credential_state(), CredentialState::Banned);
     assert_eq!(
-        store
-            .account(account_id)
-            .expect("account after deactivation")
-            .availability(),
-        AccountAvailability::Banned
-    );
-    assert_eq!(
-        store.last_error_message(account_id).as_deref(),
-        Some("deactivated_workspace")
+        current.last_error_reason(),
+        Some(gateway_core::engine::credential::AccountErrorReason::AccountBanned)
     );
 }
diff --git a/backend/crates/providers/openai/tests/credential/quota/snapshot.rs b/backend/crates/providers/openai/tests/credential/quota/snapshot.rs
index 2b3851e13..e20f85326 100644
--- a/backend/crates/providers/openai/tests/credential/quota/snapshot.rs
+++ b/backend/crates/providers/openai/tests/credential/quota/snapshot.rs
@@ -7,7 +7,8 @@ use std::time::{Duration, SystemTime};
 
 use futures::future::join_all;
 use gateway_core::engine::credential::{
-    OpaqueProviderData, ProviderAccountStore as _, QuotaObservation, QuotaWriteOutcome,
+    OpaqueProviderData, ProviderAccountStore as _, QuotaAccessState, QuotaObservation, QuotaState,
+    QuotaWriteOutcome,
 };
 use provider_openai::credential::{CodexQuotaWindowKind, parse_codex_quota_usage};
 use serde_json::json;
@@ -34,11 +35,11 @@ fn parser_extracts_dynamic_windows_without_a_fixed_database_shape() {
         fact.resets_at().map(|value| value.timestamp()),
         Some(1_800_000_100)
     );
-    assert!(!fact.exhausted());
+    assert_eq!(fact.remaining_percent(), Some(20));
 }
 
 #[test]
-fn parser_treats_any_confirmed_provider_limit_as_exhausted() {
+fn parser_keeps_additional_limit_as_display_data() {
     let fact = parse_codex_quota_usage(&json!({
         "rate_limit": {"primary_window": {"used_percent": 10}},
         "additional_rate_limits": [{
@@ -47,7 +48,7 @@ fn parser_treats_any_confirmed_provider_limit_as_exhausted() {
     }))
     .expect("valid quota");
 
-    assert!(fact.exhausted());
+    assert_eq!(fact.remaining_percent(), Some(0));
 }
 
 #[test]
@@ -61,14 +62,12 @@ fn parser_keeps_full_percent_as_display_without_provider_exhaustion_signal() {
     }))
     .expect("valid full-percent quota");
 
-    // 任一子窗口 used>=100 是快照级 exhaustion 事实，
-    // 即使顶层 allowed=true。
+    // 百分比只负责展示；额度访问结论由规范化 QuotaState 承载。
     assert_eq!(fact.remaining_percent(), Some(0));
-    assert!(fact.exhausted());
 }
 
 #[test]
-fn parser_treats_confirmed_limit_reached_as_exhausted_even_below_full_percent() {
+fn parser_projects_percent_when_access_is_denied() {
     let fact = parse_codex_quota_usage(&json!({
         "rate_limit": {
             "allowed": false,
@@ -79,7 +78,6 @@ fn parser_treats_confirmed_limit_reached_as_exhausted_even_below_full_percent()
     .expect("valid provider-confirmed quota");
 
     assert_eq!(fact.remaining_percent(), Some(2));
-    assert!(fact.exhausted());
 }
 
 #[test]
@@ -94,7 +92,7 @@ fn parser_does_not_infer_exhaustion_from_unknown_credit_fields() {
     }))
     .expect("recognized credits object");
 
-    assert!(!fact.exhausted());
+    assert_eq!(fact.remaining_percent(), None);
 }
 
 #[test]
@@ -129,7 +127,6 @@ fn parser_accepts_official_null_additional_rate_limits() {
     .expect("official null additional quota");
 
     assert_eq!(fact.remaining_percent(), Some(70));
-    assert!(!fact.exhausted());
 }
 
 #[test]
@@ -192,11 +189,9 @@ async fn persisted_provider_quota_projects_dynamic_windows_without_network_io()
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::allowed(SystemTime::now()),
         })
         .await
         .expect("persist quota");
@@ -218,8 +213,7 @@ async fn persisted_provider_quota_projects_dynamic_windows_without_network_io()
 }
 
 #[tokio::test]
-async fn roll_expired_windows_is_o1_for_extremely_old_reset() {
-    // 过去数年的 1 秒窗口：O(1) 完成，不能线性循环。
+async fn expired_window_remains_the_last_observation_until_refresh() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_o1_roll").await;
     let account = store.account("acct_o1_roll").expect("account");
@@ -240,11 +234,9 @@ async fn roll_expired_windows_is_o1_for_extremely_old_reset() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::observed_unknown(SystemTime::now()),
         })
         .await
         .expect("persist quota");
@@ -254,20 +246,18 @@ async fn roll_expired_windows_is_o1_for_extremely_old_reset() {
         .await
         .expect("read quota")
         .expect("quota snapshot");
-    let rolled = snapshot.roll_expired_windows(SystemTime::now());
-    let window = &rolled.windows()[0];
-    assert_eq!(window.used_percent(), Some(0.0));
-    assert!(!window.limit_reached());
-    // 下一 reset 必须落在 now 之后（O(1) 公式而非线性累加）。
+    let window = &snapshot.windows()[0];
+    assert_eq!(window.used_percent(), Some(100.0));
     assert!(
         window
             .reset_at()
-            .is_some_and(|reset| SystemTime::from(reset) > SystemTime::now())
+            .is_some_and(|reset| { SystemTime::from(reset) < SystemTime::now() })
     );
+    assert_eq!(service.scheduling_signals(&account), None);
 }
 
 #[tokio::test]
-async fn scheduling_signal_survives_limit_reached_without_percent_or_reset() {
+async fn persisted_access_fact_survives_limit_without_percent_or_reset() {
     let store = Arc::new(MemoryAccountStore::default());
     create_account(&store, "acct_signal_only_limit").await;
     let account = store.account("acct_signal_only_limit").expect("account");
@@ -282,11 +272,13 @@ async fn scheduling_signal_survives_limit_reached_without_percent_or_reset() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::exhausted(
+                gateway_core::engine::credential::QuotaEvidence::ProviderDenied,
+                SystemTime::now(),
+                None,
+            ),
         })
         .await
         .expect("persist quota");
@@ -296,12 +288,7 @@ async fn scheduling_signal_survives_limit_reached_without_percent_or_reset() {
         .await
         .expect("read quota")
         .expect("quota snapshot");
-    assert!(snapshot.fact().exhausted());
-    let signals = service.scheduling_signals(&account);
-    assert!(
-        signals.is_some_and(|signals| signals.limit_reached()),
-        "limit_reached without percent/reset must still produce scheduling exclusion"
-    );
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Exhausted);
 }
 
 #[tokio::test]
@@ -334,11 +321,9 @@ async fn persisted_codex_alias_keeps_the_top_level_rate_limit_canonical() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::observed_unknown(SystemTime::now()),
         })
         .await
         .expect("persist quota");
@@ -393,11 +378,9 @@ async fn persisted_quota_orders_core_window_before_additional_limit() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::observed_unknown(SystemTime::now()),
         })
         .await
         .expect("persist quota");
@@ -459,11 +442,9 @@ async fn code_review_limit_projects_as_independent_window_with_limit_name() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
-                raw.as_object().expect("quota object").clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(raw.as_object().expect("quota object").clone()),
+            observed_at: SystemTime::now(),
+            state: QuotaState::observed_unknown(SystemTime::now()),
         })
         .await
         .expect("persist quota");
@@ -490,5 +471,5 @@ async fn code_review_limit_projects_as_independent_window_with_limit_name() {
     }));
     assert_ne!(review[0].key(), review[1].key());
     assert_eq!(snapshot.windows().len(), 3);
-    assert!(!snapshot.fact().exhausted());
+    assert_eq!(snapshot.quota().access(), QuotaAccessState::Unknown);
 }
diff --git a/backend/crates/providers/openai/tests/provider/contract.rs b/backend/crates/providers/openai/tests/provider/contract.rs
index 608bac059..c5591e06f 100644
--- a/backend/crates/providers/openai/tests/provider/contract.rs
+++ b/backend/crates/providers/openai/tests/provider/contract.rs
@@ -7,8 +7,9 @@ use base64::{Engine as _, engine::general_purpose::STANDARD};
 use chrono::Utc;
 use futures::{SinkExt, StreamExt};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountFeedbackStats, OpaqueProviderData, ProviderAccountId,
-    ProviderAccountStore as _, QuotaObservation,
+    AccountFeedbackStats, CredentialState, OpaqueProviderData, ProviderAccountId,
+    ProviderAccountStore as _, QuotaAccessChange, QuotaAccessState, QuotaEvidence,
+    QuotaObservation, QuotaState,
 };
 use gateway_core::engine::provider::{Provider as _, ProviderRequest};
 use gateway_core::engine::{
@@ -166,7 +167,6 @@ fn provider_and_quota_with_affinity_and_base_url_and_leases(
         Arc::clone(&agent_identity),
         Arc::clone(&account_feedback),
         CodexCookiePolicy::official().expect("cookie policy"),
-        true,
     ));
 
     let provider = CodexProvider::new(
@@ -1414,25 +1414,26 @@ async fn response_failed_before_semantic_output_is_atomic_and_persists_quota_loc
         vec!["response.created", "response.failed"]
     );
     let account = store.account(account_id).expect("rate-limited account");
-    // 429 只记录限流窗口，不改变 availability（限流不改变账号可用性）。
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
+    assert_eq!(account.quota().access(), QuotaAccessState::Unknown);
     let _ = release.send(());
     server.abort();
     let _ = server.await;
 }
 
 #[tokio::test]
-async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset_advances() {
+async fn official_usage_limit_failure_persists_fact_without_fabricating_usage() {
     let store = Arc::new(MemoryAccountStore::default());
     let account_id = "acct_usage_limit_request_path";
     let reset_at = 1_900_000_000;
     create_account(&store, account_id).await;
     let account = store.account(account_id).expect("created account");
+    let observed_at = SystemTime::now();
     store
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
+            quota: OpaqueProviderData::new(
                 json!({
                     "rate_limit": {
                         "allowed": true,
@@ -1444,9 +1445,9 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
                 .as_object()
                 .expect("stale quota object")
                 .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            ),
+            observed_at,
+            state: QuotaState::allowed(observed_at),
         })
         .await
         .expect("seed stale passive quota");
@@ -1505,7 +1506,11 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
 
     assert_eq!(failure.kind(), ProviderErrorKind::QuotaExhausted);
     let account = store.account(account_id).expect("usage-limit account");
-    assert_eq!(account.availability(), AccountAvailability::QuotaExhausted);
+    assert_eq!(account.quota().access(), QuotaAccessState::Exhausted);
+    assert_eq!(
+        account.quota().evidence(),
+        Some(QuotaEvidence::UsageLimitReached)
+    );
     let projected = store
         .get_quotas(&[account.id().clone()])
         .await
@@ -1513,22 +1518,20 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
         .into_iter()
         .next()
         .expect("confirmed quota observation");
-    let projected_observed_at = projected.observed_at.expect("projection observed at");
-    let projected = Value::Object(
-        projected
-            .quota
-            .map(OpaqueProviderData::into_inner)
-            .expect("confirmed quota projection"),
-    );
+    let projected_observed_at = projected.observed_at;
+    let projected = Value::Object(projected.quota.into_inner());
     assert_eq!(
         projected
             .pointer("/rate_limit/primary_window/used_percent")
             .and_then(Value::as_u64),
-        Some(100)
+        Some(99)
     );
-    assert!(
-        projected.pointer("/rate_limit/secondary_window").is_none(),
-        "request failure must not manufacture a secondary quota"
+    assert_eq!(
+        projected
+            .pointer("/rate_limit/secondary_window/used_percent")
+            .and_then(Value::as_u64),
+        Some(0),
+        "request failure must not rewrite the raw display document"
     );
     tokio::time::sleep(Duration::from_millis(200)).await;
     let requests = server.received_requests().await.expect("received requests");
@@ -1549,7 +1552,7 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
                 .expect("read refreshed quota observation")
                 .into_iter()
                 .next()
-                .and_then(|observation| observation.observed_at);
+                .map(|observation| observation.observed_at);
             if observed_at.is_some_and(|observed_at| observed_at > projected_observed_at) {
                 break;
             }
@@ -1564,15 +1567,14 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
         .expect("read refreshed quota")
         .into_iter()
         .next()
-        .and_then(|observation| observation.quota)
-        .map(OpaqueProviderData::into_inner)
+        .map(|observation| observation.quota.into_inner())
         .map(Value::Object)
         .expect("authoritative quota projection");
     assert_eq!(
         quota
             .pointer("/rate_limit/primary_window/used_percent")
             .and_then(Value::as_u64),
-        Some(100)
+        Some(99)
     );
     assert_eq!(
         quota
@@ -1582,7 +1584,7 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
     );
     assert!(
         quota.pointer("/rate_limit/secondary_window").is_none(),
-        "background quota refresh must retain the same window projection"
+        "background refresh may normalize empty display windows"
     );
     let requests = server.received_requests().await.expect("received requests");
     assert_eq!(
@@ -1596,8 +1598,9 @@ async fn official_usage_limit_failure_projects_100_percent_and_holds_until_reset
         store
             .account(account_id)
             .expect("account after stale full usage refresh")
-            .availability(),
-        AccountAvailability::QuotaExhausted,
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted,
         "a contradictory full usage snapshot must not unlock a confirmed exhausted account"
     );
 }
@@ -1976,12 +1979,11 @@ async fn disabled_account_diagnostic_uses_upstream_without_persisting_account_st
     create_account(&store, account_id).await;
     let account = store.account(account_id).expect("test account");
     store
-        .repository()
-        .apply_state(
-            &account,
-            AccountAvailability::QuotaExhausted,
-            SystemTime::now(),
-        )
+        .apply_quota_access(QuotaAccessChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            state: QuotaState::exhausted(QuotaEvidence::UsageLimitReached, SystemTime::now(), None),
+        })
         .await
         .expect("seed quota-exhausted state");
     store
@@ -2033,7 +2035,7 @@ async fn disabled_account_diagnostic_uses_upstream_without_persisting_account_st
         .account(account_id)
         .expect("disabled test account after test");
     assert!(!account.enabled());
-    assert_eq!(account.availability(), AccountAvailability::QuotaExhausted);
+    assert_eq!(account.quota().access(), QuotaAccessState::Exhausted);
     assert!(!store.has_quota(account_id));
     assert_eq!(affinity.binding_count(), 0);
 }
@@ -2051,18 +2053,19 @@ async fn quota_limited_account_diagnostic_uses_upstream() {
             "primary_window": {"used_percent": 100, "reset_at": 1_900_000_000}
         }
     });
+    let observed_at = SystemTime::now();
     store
         .compare_and_swap_quota(QuotaObservation {
             account_id: account.id().clone(),
             expected_revision: account.revision(),
-            quota: Some(OpaqueProviderData::new(
+            quota: OpaqueProviderData::new(
                 raw_quota
                     .as_object()
                     .expect("quota snapshot object")
                     .clone(),
-            )),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: Some(true),
+            ),
+            observed_at,
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, observed_at, None),
         })
         .await
         .expect("seed quota-limited snapshot");
@@ -2118,7 +2121,7 @@ async fn quota_limited_account_diagnostic_uses_upstream() {
 }
 
 #[tokio::test]
-async fn successful_response_preserves_quota_exhaustion_from_rate_limit_headers() {
+async fn successful_response_treats_inference_success_as_authoritative_allowance() {
     let store = Arc::new(MemoryAccountStore::default());
     let account_id = "acct_success_exhausted";
     create_account(&store, account_id).await;
@@ -2164,8 +2167,9 @@ async fn successful_response_preserves_quota_exhaustion_from_rate_limit_headers(
         store
             .account(account_id)
             .expect("account after successful response")
-            .availability(),
-        AccountAvailability::Ready
+            .quota()
+            .access(),
+        QuotaAccessState::Allowed
     );
     assert!(store.has_quota(account_id));
 }
@@ -2226,10 +2230,9 @@ async fn successful_http_sse_rate_limit_event_persists_structured_exhaustion() {
     let account = store
         .account(account_id)
         .expect("account after HTTP SSE response");
-    assert_eq!(
-        (account.availability(), store.has_quota(account_id),),
-        (AccountAvailability::Ready, true,)
-    );
+    assert_eq!(account.credential_state(), CredentialState::Ready);
+    assert_eq!(account.quota().access(), QuotaAccessState::Allowed);
+    assert!(store.has_quota(account_id));
 }
 
 #[test]
diff --git a/backend/crates/providers/openai/tests/support.rs b/backend/crates/providers/openai/tests/support.rs
index bfd763be0..879120f46 100644
--- a/backend/crates/providers/openai/tests/support.rs
+++ b/backend/crates/providers/openai/tests/support.rs
@@ -9,10 +9,10 @@ use std::time::{Duration, SystemTime};
 use async_trait::async_trait;
 use futures::future::BoxFuture;
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountRuntimeSignals, AccountStateChange, CredentialCasOutcome,
-    CredentialCasUpdate, CredentialRevision, LoadedCredential, NewProviderAccount,
+    AccountErrorReason, AccountRuntimeSignals, AccountStateChange, CredentialCasOutcome,
+    CredentialCasUpdate, CredentialRevision, CredentialState, LoadedCredential, NewProviderAccount,
     OpaqueProviderData, ProviderAccount, ProviderAccountId, ProviderAccountStore,
-    ProviderAccountUpdate, QuotaObservation, QuotaWriteOutcome,
+    ProviderAccountUpdate, QuotaAccessChange, QuotaObservation, QuotaState, QuotaWriteOutcome,
 };
 use gateway_core::error::{StoreError, StoreErrorKind};
 use gateway_core::provider_ports::{
@@ -38,7 +38,6 @@ struct StoredAccount {
     credential: gateway_core::engine::credential::PlaintextCredential,
     quota: Option<QuotaObservation>,
     state_observed_at: Option<SystemTime>,
-    last_error_message: Option<String>,
 }
 
 #[derive(Default)]
@@ -71,15 +70,6 @@ impl MemoryAccountStore {
             .map(|stored| stored.account.clone())
     }
 
-    pub(crate) fn last_error_message(&self, id: &str) -> Option<String> {
-        let id = ProviderAccountId::new(id).ok()?;
-        self.accounts
-            .lock()
-            .expect("account store lock")
-            .get(&id)
-            .and_then(|stored| stored.last_error_message.clone())
-    }
-
     pub(crate) fn quota_reads(&self) -> usize {
         self.quota_reads.load(Ordering::SeqCst)
     }
@@ -102,8 +92,9 @@ impl MemoryAccountStore {
             .expect("account store lock")
             .get(&id)
             .and_then(|stored| stored.quota.as_ref())
-            .and_then(|observation| observation.quota.as_ref())
-            .map(|data| serde_json::Value::Object(data.expose_to_provider().clone()))
+            .map(|observation| {
+                serde_json::Value::Object(observation.quota.expose_to_provider().clone())
+            })
     }
 
     pub(crate) fn fail_provider_listing(&self) {
@@ -125,7 +116,6 @@ impl ProviderAccountStore for MemoryAccountStore {
                 credential: input.credential,
                 quota: None,
                 state_observed_at: None,
-                last_error_message: None,
             },
         );
         Ok(())
@@ -224,7 +214,10 @@ impl ProviderAccountStore for MemoryAccountStore {
             AccountRebuild {
                 revision: next,
                 enabled: stored.account.enabled(),
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 access_token_expires_at,
                 has_refresh_token,
                 next_refresh_at,
@@ -262,13 +255,37 @@ impl ProviderAccountStore for MemoryAccountStore {
         if stored
             .quota
             .as_ref()
-            .and_then(|quota| quota.observed_at)
-            .zip(observation.observed_at)
-            .is_some_and(|(current, incoming)| current > incoming)
+            .is_some_and(|quota| quota.observed_at > observation.observed_at)
         {
             return Ok(QuotaWriteOutcome::Conflict);
         }
+        let quota = observation.state;
         stored.quota = Some(observation);
+        stored.account = rebuild_account(
+            &stored.account,
+            AccountRebuild::preserving(&stored.account).with_quota(quota),
+        );
+        Ok(QuotaWriteOutcome::Updated)
+    }
+
+    async fn apply_quota_access(
+        &self,
+        change: QuotaAccessChange,
+    ) -> Result<QuotaWriteOutcome, StoreError> {
+        let mut accounts = self.accounts.lock().expect("account store lock");
+        let stored = accounts
+            .get_mut(&change.account_id)
+            .ok_or_else(|| store_error(StoreErrorKind::InvalidData))?;
+        if stored.account.revision() != change.expected_revision {
+            return Ok(QuotaWriteOutcome::Conflict);
+        }
+        stored.account = rebuild_account(
+            &stored.account,
+            AccountRebuild::preserving(&stored.account).with_quota(change.state),
+        );
+        if let Some(observation) = &mut stored.quota {
+            observation.state = change.state;
+        }
         Ok(QuotaWriteOutcome::Updated)
     }
 
@@ -291,7 +308,10 @@ impl ProviderAccountStore for MemoryAccountStore {
             AccountRebuild {
                 revision: stored.account.revision(),
                 enabled: stored.account.enabled(),
-                availability: change.availability,
+                credential_state: change.credential_state,
+                quota: stored.account.quota(),
+                last_error_reason: change.error_reason,
+                last_error_message: change.message,
                 access_token_expires_at: stored.account.access_token_expires_at(),
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -299,11 +319,6 @@ impl ProviderAccountStore for MemoryAccountStore {
             },
         );
         stored.state_observed_at = Some(change.observed_at);
-        if change.availability == AccountAvailability::Ready {
-            stored.last_error_message = None;
-        } else if let Some(message) = change.message {
-            stored.last_error_message = Some(message);
-        }
         Ok(())
     }
 
@@ -317,7 +332,10 @@ impl ProviderAccountStore for MemoryAccountStore {
             AccountRebuild {
                 revision: stored.account.revision(),
                 enabled: stored.account.enabled(),
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 access_token_expires_at: stored.account.access_token_expires_at(),
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -341,7 +359,10 @@ impl ProviderAccountStore for MemoryAccountStore {
             AccountRebuild {
                 revision: stored.account.revision(),
                 enabled,
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 access_token_expires_at: stored.account.access_token_expires_at(),
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -368,13 +389,38 @@ const fn store_error(kind: StoreErrorKind) -> StoreError {
 struct AccountRebuild {
     revision: CredentialRevision,
     enabled: bool,
-    availability: AccountAvailability,
+    credential_state: CredentialState,
+    quota: QuotaState,
+    last_error_reason: Option<AccountErrorReason>,
+    last_error_message: Option<String>,
     access_token_expires_at: Option<SystemTime>,
     has_refresh_token: bool,
     next_refresh_at: Option<SystemTime>,
     profile: Option<(String, Option<String>, Option<String>)>,
 }
 
+impl AccountRebuild {
+    fn preserving(account: &ProviderAccount) -> Self {
+        Self {
+            revision: account.revision(),
+            enabled: account.enabled(),
+            credential_state: account.credential_state(),
+            quota: account.quota(),
+            last_error_reason: account.last_error_reason(),
+            last_error_message: account.last_error_message().map(str::to_owned),
+            access_token_expires_at: account.access_token_expires_at(),
+            has_refresh_token: account.has_refresh_token(),
+            next_refresh_at: account.next_refresh_at(),
+            profile: None,
+        }
+    }
+
+    fn with_quota(mut self, quota: QuotaState) -> Self {
+        self.quota = quota;
+        self
+    }
+}
+
 fn rebuild_account(current: &ProviderAccount, rebuild: AccountRebuild) -> ProviderAccount {
     let (name, email, plan_type) = rebuild.profile.unwrap_or_else(|| {
         (
@@ -397,7 +443,13 @@ fn rebuild_account(current: &ProviderAccount, rebuild: AccountRebuild) -> Provid
         current.upstream_account_id().map(str::to_owned),
         plan_type,
     )
-    .with_runtime_state(rebuild.enabled, rebuild.availability)
+    .with_account_facts(
+        rebuild.enabled,
+        rebuild.credential_state,
+        rebuild.quota,
+        rebuild.last_error_reason,
+        rebuild.last_error_message,
+    )
     .with_refresh_schedule(rebuild.has_refresh_token, rebuild.next_refresh_at)
 }
 
@@ -450,7 +502,7 @@ impl ProviderLeasePort for TestLeaseCoordinator {
                             last_started_at: None,
                             quota_reset_at: None,
                             quota_remaining_rank: None,
-                            quota_limit_reached: false,
+                            rate_limited_until: None,
                             failure_rate_basis_points: None,
                             first_output_latency_ms: None,
                         },
diff --git a/backend/crates/providers/xai/src/admin.rs b/backend/crates/providers/xai/src/admin.rs
index f1b1db017..f70f0d59e 100644
--- a/backend/crates/providers/xai/src/admin.rs
+++ b/backend/crates/providers/xai/src/admin.rs
@@ -660,19 +660,21 @@ impl ProviderAdmin for XaiAdminProvider {
             refresh,
             rolling_usage,
         } = request;
-        self.account(&account_id).await?;
+        let mut account = self.account(&account_id).await?;
         let lifecycle = self
             .repository
             .read_lifecycle(&account_id)
             .await
             .map_err(map_repository_error)?;
         let snapshot = if refresh {
-            Some(
+            let snapshot = Some(
                 self.quota
                     .refresh_account(&account_id)
                     .await
                     .map_err(map_quota_error)?,
-            )
+            );
+            account = self.account(&account_id).await?;
+            snapshot
         } else {
             self.quota
                 .read_account(&account_id)
@@ -681,6 +683,7 @@ impl ProviderAdmin for XaiAdminProvider {
         };
         Ok(project_quota(
             snapshot,
+            account.quota().is_exhausted(),
             lifecycle.refresh_token_expires_at().copied(),
             rolling_usage,
         ))
@@ -891,8 +894,8 @@ fn prepared_create(
         access_token_expires_at: account.access_token_expires_at().map(DateTime::<Utc>::from),
         next_refresh_at: account.next_refresh_at().map(Into::into),
         enabled: account.enabled(),
-        availability: account.availability(),
-        availability_observed_at: observed_at,
+        credential_state: account.credential_state(),
+        credential_observed_at: observed_at,
     })
 }
 
@@ -995,7 +998,13 @@ fn account_from_record(account: &AccountRecord) -> Result<ProviderAccount, Provi
         account.upstream_account_id.clone(),
         account.plan_type.clone(),
     )
-    .with_runtime_state(account.enabled, account.availability)
+    .with_account_facts(
+        account.enabled,
+        account.credential_state,
+        account.quota,
+        account.last_error_reason,
+        account.last_error_message.clone(),
+    )
     .with_refresh_schedule(
         account.has_refresh_token,
         account.next_refresh_at.map(Into::into),
@@ -1012,6 +1021,7 @@ fn account_matches_record(account: &ProviderAccount, record: &AccountRecord) ->
 
 fn project_quota(
     snapshot: Option<GrokQuotaSnapshot>,
+    quota_exhausted: bool,
     refresh_token_expires_at: Option<DateTime<Utc>>,
     rolling_usage: Option<gateway_admin::model::accounts::AccountUsage>,
 ) -> ProviderQuota {
@@ -1020,8 +1030,7 @@ fn project_quota(
             observed_at: None,
             refresh_token_expires_at,
             windows: Vec::new(),
-            limit_reached: false,
-            rate_limited_until: None,
+            limit_reached: quota_exhausted,
             provider_data: None,
         };
     };
@@ -1088,10 +1097,7 @@ fn project_quota(
         observed_at: Some(snapshot.observed_at()),
         refresh_token_expires_at,
         windows: vec![window],
-        limit_reached: billing
-            .used_percent()
-            .is_some_and(|used| used.is_finite() && used >= 100.0),
-        rate_limited_until: None,
+        limit_reached: quota_exhausted,
         provider_data: None,
     }
 }
diff --git a/backend/crates/providers/xai/src/credential/catalog.rs b/backend/crates/providers/xai/src/credential/catalog.rs
index 803f270d0..bc1b93452 100644
--- a/backend/crates/providers/xai/src/credential/catalog.rs
+++ b/backend/crates/providers/xai/src/credential/catalog.rs
@@ -8,8 +8,8 @@ use std::time::{Duration, Instant, SystemTime};
 use async_trait::async_trait;
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountQuotaSignals, CredentialRevision, OpaqueProviderData,
-    ProviderAccount, ProviderAccountId, QuotaObservation,
+    AccountQuotaSignals, CredentialRevision, CredentialState, OpaqueProviderData, ProviderAccount,
+    ProviderAccountId, QuotaObservation, QuotaState,
 };
 use gateway_core::engine::provider::ProviderCatalogGeneration;
 use gateway_core::provider_ports::{
@@ -19,7 +19,6 @@ use gateway_core::routing::ProviderKind;
 use tokio::sync::Mutex;
 
 use super::repository::{GrokCredentialRepository, LoadedGrokCredential};
-use super::types::{GrokCredentialAvailability, UpdateGrokCredentialState};
 use crate::XaiWireProfileState;
 use crate::transport::catalog::{MAX_CATALOG_MODELS, valid_model_slug, validate_etag};
 use crate::{
@@ -445,15 +444,17 @@ impl GrokCredentialQuotaService {
         let observed_at = Utc::now();
         let document = billing.into_document();
         let presentation = billing_presentation(&document)?;
+        let quota = loaded
+            .account
+            .quota()
+            .merge_observation(quota_access_observation(&presentation, observed_at.into()));
         self.repository
             .replace_quota(
                 loaded.account.id().clone(),
                 loaded.account.revision(),
                 document,
                 observed_at.into(),
-                presentation
-                    .used_percent()
-                    .is_some_and(|used| used.is_finite() && used >= 100.0),
+                quota,
             )
             .await
             .map_err(map_quota_repository_error)?;
@@ -464,32 +465,6 @@ impl GrokCredentialQuotaService {
             billing: presentation,
         };
         self.scheduling.observe(&snapshot);
-        let current = self
-            .repository
-            .load_current(account_id)
-            .await
-            .map_err(map_quota_repository_error)?;
-        if quota_refresh_may_update_state(&loaded.account, &current.account)
-            && let Some(availability) = quota_refresh_availability(
-                current.account.availability(),
-                authoritative_quota_exhaustion(snapshot.billing()),
-            )
-        {
-            self.repository
-                .update_state(&UpdateGrokCredentialState {
-                    account_id: current.account.id().clone(),
-                    expected_revision: current.account.revision(),
-                    availability,
-                    availability_reason: matches!(
-                        availability,
-                        GrokCredentialAvailability::QuotaExhausted
-                    )
-                    .then_some("quota_exhausted".to_owned()),
-                    observed_at,
-                })
-                .await
-                .map_err(map_quota_repository_error)?;
-        }
         Ok(snapshot)
     }
 
@@ -506,10 +481,8 @@ impl GrokCredentialQuotaService {
         else {
             return Ok(None);
         };
-        let (Some(quota), Some(observed_at)) = (observation.quota, observation.observed_at) else {
-            return Err(GrokQuotaError::InvalidData);
-        };
-        let document = quota.into_inner();
+        let observed_at = observation.observed_at;
+        let document = observation.quota.into_inner();
         let snapshot = GrokQuotaSnapshot {
             account_id: observation.account_id,
             credential_revision: observation.expected_revision,
@@ -1150,14 +1123,10 @@ fn eligible_catalog_candidate(candidate: &LoadedGrokCredential) -> bool {
         && candidate
             .refresh_token_expires_at
             .is_none_or(|expires_at| expires_at > Utc::now())
-        && match account.availability() {
-            AccountAvailability::Unknown
-            | AccountAvailability::Ready
-            | AccountAvailability::QuotaExhausted => true,
-            AccountAvailability::Expired
-            | AccountAvailability::Banned
-            | AccountAvailability::Invalid => false,
-        }
+        && matches!(
+            account.credential_state(),
+            CredentialState::Unknown | CredentialState::Ready
+        )
 }
 
 async fn fetch_candidate_catalog(
@@ -1273,8 +1242,8 @@ fn billing_presentation(
 }
 
 fn quota_snapshot_from_observation(observation: &QuotaObservation) -> Option<GrokQuotaSnapshot> {
-    let observed_at = DateTime::<Utc>::from(observation.observed_at?);
-    let document = observation.quota.as_ref()?.expose_to_provider();
+    let observed_at = DateTime::<Utc>::from(observation.observed_at);
+    let document = observation.quota.expose_to_provider();
     Some(GrokQuotaSnapshot {
         account_id: observation.account_id.clone(),
         credential_revision: observation.expected_revision,
@@ -1293,29 +1262,54 @@ fn quota_projection_ttl(observed_at: DateTime<Utc>) -> Option<Duration> {
 }
 
 fn quota_scheduling_signals(billing: &GrokBillingPresentation) -> Option<AccountQuotaSignals> {
-    let remaining_rank = billing
-        .used_percent()
-        .filter(|used| used.is_finite() && (0.0..=100.0).contains(used))
-        .map(|used| ((100.0 - used) * 100.0).round() as u64);
     let now = SystemTime::now();
-    let reset_at = billing
+    let period_end = billing
+        .period_end()
+        .and_then(|value| DateTime::parse_from_rfc3339(value).ok())
+        .map(|value| SystemTime::from(value.to_utc()));
+    let observation_expired = period_end.is_some_and(|period_end| period_end <= now);
+    let remaining_rank = (!observation_expired)
+        .then(|| {
+            billing
+                .used_percent()
+                .filter(|used| used.is_finite() && (0.0..=100.0).contains(used))
+                .map(|used| ((100.0 - used) * 100.0).round() as u64)
+        })
+        .flatten();
+    let reset_at = period_end.filter(|reset_at| *reset_at > now);
+    (remaining_rank.is_some() || reset_at.is_some())
+        .then(|| AccountQuotaSignals::new(reset_at, remaining_rank))
+}
+
+/// 把 xAI billing 文档归一化为访问结论。缺少正反证据时返回 Unknown，
+/// 由 `QuotaState::merge_observation` 保留既有已确认结论。
+fn quota_access_observation(
+    billing: &GrokBillingPresentation,
+    observed_at: SystemTime,
+) -> QuotaState {
+    if !billing.has_authoritative_quota() {
+        return QuotaState::observed_unknown(observed_at);
+    }
+    if billing_proves_access_allowed(billing, observed_at) {
+        QuotaState::allowed(observed_at)
+    } else {
+        QuotaState::observed_unknown(observed_at)
+    }
+}
+
+fn billing_proves_access_allowed(
+    billing: &GrokBillingPresentation,
+    observed_at: SystemTime,
+) -> bool {
+    if billing
         .period_end()
         .and_then(|value| DateTime::parse_from_rfc3339(value).ok())
         .map(|value| SystemTime::from(value.to_utc()))
-        .filter(|reset_at| *reset_at > now);
-    (remaining_rank.is_some() || reset_at.is_some()).then(|| {
-        AccountQuotaSignals::new(
-            reset_at,
-            remaining_rank,
-            billing
-                .used_percent()
-                .is_some_and(|used| used.is_finite() && used >= 100.0),
-        )
-    })
-}
-
-fn quota_is_exhausted(billing: &GrokBillingPresentation) -> bool {
-    if billing
+        .is_some_and(|period_end| period_end <= observed_at)
+    {
+        return false;
+    }
+    billing
         .prepaid_balance_cents()
         .is_some_and(|balance| balance > 0)
         || billing
@@ -1329,60 +1323,6 @@ fn quota_is_exhausted(billing: &GrokBillingPresentation) -> bool {
             (billing.included_used_cents(), billing.monthly_limit_cents()),
             (Some(used), Some(limit)) if limit > 0 && used < limit
         )
-    {
-        return false;
-    }
-    billing
-        .used_percent()
-        .is_some_and(|used| used.is_finite() && used >= 100.0)
-        || matches!(
-            (billing.included_used_cents(), billing.monthly_limit_cents()),
-            (Some(used), Some(limit)) if limit > 0 && used >= limit
-        )
-        || matches!(
-            (billing.on_demand_used_cents(), billing.on_demand_cap_cents()),
-            (Some(used), Some(cap)) if cap > 0 && used >= cap
-        )
-}
-
-/// `None` means the billing document cannot prove either quota state.
-fn authoritative_quota_exhaustion(billing: &GrokBillingPresentation) -> Option<bool> {
-    billing
-        .has_authoritative_quota()
-        .then(|| quota_is_exhausted(billing))
-}
-
-fn quota_refresh_may_update_state(before: &ProviderAccount, current: &ProviderAccount) -> bool {
-    current.enabled()
-        && current
-            .access_token_expires_at()
-            .is_some_and(|expires_at| expires_at > SystemTime::now())
-        && current.revision() == before.revision()
-        && current.availability() == before.availability()
-}
-
-fn quota_refresh_availability(
-    current: AccountAvailability,
-    exhausted: Option<bool>,
-) -> Option<GrokCredentialAvailability> {
-    match current {
-        AccountAvailability::Invalid
-        | AccountAvailability::Expired
-        | AccountAvailability::Banned => None,
-        AccountAvailability::QuotaExhausted => {
-            matches!(exhausted, Some(false)).then_some(GrokCredentialAvailability::Ready)
-        }
-        AccountAvailability::Unknown => exhausted.map(|exhausted| {
-            if exhausted {
-                GrokCredentialAvailability::QuotaExhausted
-            } else {
-                GrokCredentialAvailability::Ready
-            }
-        }),
-        AccountAvailability::Ready => {
-            matches!(exhausted, Some(true)).then_some(GrokCredentialAvailability::QuotaExhausted)
-        }
-    }
 }
 
 fn dynamic_string(
diff --git a/backend/crates/providers/xai/src/credential/mod.rs b/backend/crates/providers/xai/src/credential/mod.rs
index f2344712e..5a6e7d0ff 100644
--- a/backend/crates/providers/xai/src/credential/mod.rs
+++ b/backend/crates/providers/xai/src/credential/mod.rs
@@ -63,10 +63,9 @@ pub use token::{
     parse_refresh_success,
 };
 pub use types::{
-    CreateGrokCredential, GrokAccountProfile, GrokCredentialAvailability, GrokCredentialRecord,
-    GrokOAuthSecret, PreparedGrokCredentialRotation, PreparedGrokCredentialRotationGuard,
-    RotateGrokCredential, RotateManagedGrokCredential, UpdateGrokCredentialState,
-    XAI_AUTHENTICATION_KIND_OAUTH,
+    CreateGrokCredential, GrokAccountProfile, GrokCredentialRecord, GrokOAuthSecret,
+    PreparedGrokCredentialRotation, PreparedGrokCredentialRotationGuard, RotateGrokCredential,
+    RotateManagedGrokCredential, UpdateGrokCredentialState, XAI_AUTHENTICATION_KIND_OAUTH,
 };
 pub use verification::{
     FailClosedTokenVerifier, TokenCandidate, TokenVerificationContext, TokenVerifier,
diff --git a/backend/crates/providers/xai/src/credential/refresh.rs b/backend/crates/providers/xai/src/credential/refresh.rs
index 239d91799..1704ff098 100644
--- a/backend/crates/providers/xai/src/credential/refresh.rs
+++ b/backend/crates/providers/xai/src/credential/refresh.rs
@@ -9,7 +9,7 @@ use async_trait::async_trait;
 use chrono::{DateTime, Utc};
 use futures::{StreamExt as _, stream};
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialRevision, LoadedCredential, ProviderAccountId,
+    AccountErrorReason, CredentialRevision, CredentialState, LoadedCredential, ProviderAccountId,
 };
 use gateway_core::provider_ports::{
     ProviderCredentialStatePort, ProviderLeaseAcquisition, ProviderLeasePort, ProviderLeaseRequest,
@@ -23,9 +23,8 @@ use super::repository::{
     GrokCredentialAdmin, GrokCredentialRepository, GrokCredentialRepositoryError,
 };
 use super::types::{
-    GrokAccountProfile, GrokCredentialAvailability, GrokOAuthSecret,
-    PreparedGrokCredentialRotation, RotateGrokCredential, RotateManagedGrokCredential,
-    UpdateGrokCredentialState,
+    GrokAccountProfile, GrokOAuthSecret, PreparedGrokCredentialRotation, RotateGrokCredential,
+    RotateManagedGrokCredential, UpdateGrokCredentialState,
 };
 use crate::{
     DiscoveryDocument, FailureClass, GrokOAuthClient, OAuthError, RefreshTokenGrant,
@@ -540,7 +539,8 @@ impl GrokCredentialRefreshService {
             return self
                 .persist_terminal_failure(
                     credential,
-                    GrokCredentialAvailability::Expired,
+                    CredentialState::Expired,
+                    AccountErrorReason::CredentialExpired,
                     "refresh_token_expired",
                 )
                 .await;
@@ -549,7 +549,8 @@ impl GrokCredentialRefreshService {
             return self
                 .persist_terminal_failure(
                     credential,
-                    GrokCredentialAvailability::Expired,
+                    CredentialState::Expired,
+                    AccountErrorReason::CredentialExpired,
                     "refresh_recovery_window_exhausted",
                 )
                 .await;
@@ -587,7 +588,8 @@ impl GrokCredentialRefreshService {
             Err(GrokRefreshFailure::InvalidGrant) => {
                 self.persist_terminal_failure(
                     credential,
-                    GrokCredentialAvailability::Expired,
+                    CredentialState::Expired,
+                    AccountErrorReason::CredentialExpired,
                     "refresh_invalid_grant",
                 )
                 .await
@@ -595,7 +597,8 @@ impl GrokCredentialRefreshService {
             Err(GrokRefreshFailure::Banned) => {
                 self.persist_terminal_failure(
                     credential,
-                    GrokCredentialAvailability::Banned,
+                    CredentialState::Banned,
+                    AccountErrorReason::AccountBanned,
                     "account_banned",
                 )
                 .await
@@ -717,7 +720,8 @@ impl GrokCredentialRefreshService {
     async fn persist_terminal_failure(
         &self,
         credential: DueGrokCredential,
-        availability: GrokCredentialAvailability,
+        credential_state: CredentialState,
+        error_reason: AccountErrorReason,
         reason: &str,
     ) -> Result<GrokCredentialRefreshOutcome, GrokCredentialRefreshError> {
         let account_id = credential.account_id.clone();
@@ -737,8 +741,9 @@ impl GrokCredentialRefreshService {
             .update_state(&UpdateGrokCredentialState {
                 account_id: account_id.clone(),
                 expected_revision: credential.credential_revision,
-                availability,
-                availability_reason: Some(reason.to_owned()),
+                credential_state,
+                error_reason: Some(error_reason),
+                error_message: Some(reason.to_owned()),
                 observed_at: Utc::now(),
             })
             .await
@@ -746,7 +751,7 @@ impl GrokCredentialRefreshService {
             Ok(()) => {
                 tracing::warn!(
                     account_id = %account_id,
-                    ?availability,
+                    ?credential_state,
                     reason,
                     access_token_expires_at = ?credential.access_token_expires_at
                         .map(DateTime::<Utc>::from),
@@ -915,14 +920,11 @@ fn account_due(
     policy: ProviderRefreshPolicy,
     now: SystemTime,
 ) -> bool {
-    let availability = account.availability();
     account.enabled()
         && account.has_refresh_token()
         && !matches!(
-            availability,
-            AccountAvailability::Expired
-                | AccountAvailability::Banned
-                | AccountAvailability::Invalid
+            account.credential_state(),
+            CredentialState::Expired | CredentialState::Banned | CredentialState::Invalid
         )
         && (refresh_recovery_window_exhausted(account.access_token_expires_at(), now)
             || (access_token_refresh_due(account.access_token_expires_at(), policy, now)
diff --git a/backend/crates/providers/xai/src/credential/repository.rs b/backend/crates/providers/xai/src/credential/repository.rs
index afc9e8c74..a66e90a30 100644
--- a/backend/crates/providers/xai/src/credential/repository.rs
+++ b/backend/crates/providers/xai/src/credential/repository.rs
@@ -6,10 +6,10 @@ use std::time::SystemTime;
 
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
-    CredentialRevision, LoadedCredential, NewProviderAccount, OpaqueProviderData,
-    PlaintextCredential, ProviderAccount, ProviderAccountId, ProviderAccountStore,
-    ProviderAccountUpdate, QuotaObservation, QuotaWriteOutcome,
+    AccountStateChange, CredentialCasOutcome, CredentialCasUpdate, CredentialRevision,
+    CredentialState, LoadedCredential, NewProviderAccount, OpaqueProviderData, PlaintextCredential,
+    ProviderAccount, ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate,
+    QuotaAccessChange, QuotaObservation, QuotaState, QuotaWriteOutcome,
 };
 use gateway_core::error::StoreErrorKind;
 use gateway_core::routing::ProviderKind;
@@ -17,8 +17,8 @@ use serde_json::Value;
 use thiserror::Error;
 
 use super::types::{
-    CreateGrokCredential, GrokAccountProfile, GrokCredentialAvailability, GrokCredentialRecord,
-    GrokOAuthSecret, GrokOAuthSecretWire, OwnedGrokOAuthSecretWire, PreparedGrokCredentialRotation,
+    CreateGrokCredential, GrokAccountProfile, GrokCredentialRecord, GrokOAuthSecret,
+    GrokOAuthSecretWire, OwnedGrokOAuthSecretWire, PreparedGrokCredentialRotation,
     RotateGrokCredential, RotateManagedGrokCredential, UpdateGrokCredentialState,
     XAI_AUTHENTICATION_KIND_OAUTH,
 };
@@ -167,7 +167,13 @@ impl GrokCredentialAdmin {
             input.account.upstream_account_id.clone(),
             input.account.plan_type.clone(),
         )
-        .with_runtime_state(input.enabled, input.initial_availability.into())
+        .with_account_facts(
+            input.enabled,
+            input.initial_credential_state,
+            QuotaState::unknown(),
+            input.initial_error_reason,
+            input.initial_error_message.clone(),
+        )
         .with_refresh_schedule(true, None);
         Ok(NewProviderAccount {
             account,
@@ -210,8 +216,9 @@ impl GrokCredentialAdmin {
                 refresh_token_expires_at: None,
             },
             enabled: input.enabled,
-            initial_availability: GrokCredentialAvailability::Ready,
-            initial_availability_reason: None,
+            initial_credential_state: CredentialState::Ready,
+            initial_error_reason: None,
+            initial_error_message: None,
         })
     }
 
@@ -420,21 +427,30 @@ impl GrokCredentialRepository {
         &self,
         input: &UpdateGrokCredentialState,
     ) -> Result<(), GrokCredentialRepositoryError> {
-        let availability = AccountAvailability::from(input.availability);
-        let availability_reason = input
-            .availability_reason
+        let error_message = input
+            .error_message
             .clone()
-            .filter(|value| !value.trim().is_empty())
-            .or_else(|| availability.fallback_error_reason().map(str::to_owned));
-        validate_reason(availability_reason.as_deref())?;
+            .filter(|value| !value.trim().is_empty());
+        validate_reason(error_message.as_deref())?;
+        let (error_reason, error_message) = if input.credential_state == CredentialState::Ready {
+            (None, None)
+        } else {
+            (
+                input
+                    .error_reason
+                    .or_else(|| input.credential_state.error_reason()),
+                error_message,
+            )
+        };
         self.ensure_xai_account(&input.account_id).await?;
         self.store
             .apply_state_change(AccountStateChange {
                 account_id: input.account_id.clone(),
                 expected_revision: input.expected_revision,
-                availability,
+                credential_state: input.credential_state,
                 observed_at: to_system_time(input.observed_at),
-                message: availability_reason,
+                error_reason,
+                message: error_message,
             })
             .await
             .map_err(map_store_error)
@@ -518,16 +534,39 @@ impl GrokCredentialRepository {
         expected_revision: CredentialRevision,
         document: serde_json::Map<String, Value>,
         observed_at: SystemTime,
-        limit_reached: bool,
+        state: QuotaState,
     ) -> Result<(), GrokCredentialRepositoryError> {
         let outcome = self
             .store
             .compare_and_swap_quota(QuotaObservation {
                 account_id,
                 expected_revision,
-                quota: Some(OpaqueProviderData::new(document)),
-                observed_at: Some(observed_at),
-                limit_reached: Some(limit_reached),
+                quota: OpaqueProviderData::new(document),
+                observed_at,
+                state,
+            })
+            .await
+            .map_err(map_store_error)?;
+        match outcome {
+            QuotaWriteOutcome::Updated => Ok(()),
+            QuotaWriteOutcome::Conflict => {
+                Err(GrokCredentialRepositoryError::StaleCredentialRevision)
+            }
+        }
+    }
+
+    pub(crate) async fn update_quota_access(
+        &self,
+        account_id: ProviderAccountId,
+        expected_revision: CredentialRevision,
+        state: QuotaState,
+    ) -> Result<(), GrokCredentialRepositoryError> {
+        let outcome = self
+            .store
+            .apply_quota_access(QuotaAccessChange {
+                account_id,
+                expected_revision,
+                state,
             })
             .await
             .map_err(map_store_error)?;
@@ -698,7 +737,7 @@ fn validate_create(input: &CreateGrokCredential) -> Result<(), GrokCredentialRep
     validate_name(&input.name)?;
     validate_profile(&input.account)?;
     validate_secret(&input.secret)?;
-    validate_reason(input.initial_availability_reason.as_deref())
+    validate_reason(input.initial_error_message.as_deref())
 }
 
 fn validate_profile(profile: &GrokAccountProfile) -> Result<(), GrokCredentialRepositoryError> {
@@ -786,9 +825,7 @@ fn validate_reason(reason: Option<&str>) -> Result<(), GrokCredentialRepositoryE
     if reason
         .is_some_and(|value| value.len() > MAX_REASON_BYTES || value.chars().any(char::is_control))
     {
-        return Err(GrokCredentialRepositoryError::InvalidInput(
-            "availability_reason",
-        ));
+        return Err(GrokCredentialRepositoryError::InvalidInput("error_message"));
     }
     Ok(())
 }
diff --git a/backend/crates/providers/xai/src/credential/selector.rs b/backend/crates/providers/xai/src/credential/selector.rs
index e6838a2aa..e9a4a0a88 100644
--- a/backend/crates/providers/xai/src/credential/selector.rs
+++ b/backend/crates/providers/xai/src/credential/selector.rs
@@ -6,8 +6,9 @@ use std::time::{Duration, SystemTime};
 
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountAvailabilityPolicy, AccountCandidate, AccountFeedbackStats,
-    AccountSelectionContext, AccountSelector, ProviderAccount, ProviderAccountId,
+    AccountCandidate, AccountEligibilityPolicy, AccountFeedbackStats, AccountSelectionContext,
+    AccountSelector, CredentialState, ProviderAccount, ProviderAccountId, QuotaAccessState,
+    QuotaEvidence, QuotaState,
 };
 use gateway_core::provider_ports::{
     ProviderCooldown, ProviderCooldownPort, ProviderCooldownScope, ProviderLeaseAcquisition,
@@ -18,7 +19,7 @@ use gateway_core::routing::{ProviderKind, UpstreamModelId};
 
 use super::catalog::{GrokCatalogScope, GrokCredentialCatalogCache, GrokCredentialQuotaService};
 use super::repository::{GrokCredentialRepository, GrokCredentialRepositoryError};
-use super::types::{GrokCredentialAvailability, UpdateGrokCredentialState};
+use super::types::UpdateGrokCredentialState;
 use crate::{
     GrokCredentialFailure, GrokCredentialFeedbackFuture, GrokSessionBinding, GrokSessionSelection,
     GrokSessionSelector, GrokSessionSelectorError, GrokSessionSelectorFuture, SecretValue,
@@ -82,7 +83,7 @@ impl GrokAccountSessionSelector {
         &self,
         request: GrokSessionSelection,
     ) -> Result<SelectedGrokSession, GrokSessionSelectorError> {
-        let diagnostic = request.availability() == AccountAvailabilityPolicy::BypassForDiagnostic;
+        let diagnostic = request.eligibility() == AccountEligibilityPolicy::BypassForDiagnostic;
         let accounts = self
             .repository
             .list_accounts_for_provider()
@@ -177,7 +178,7 @@ impl GrokAccountSessionSelector {
             excluded_accounts: request.excluded_accounts().clone(),
             preferred_account: request.required_account().cloned().or(affinity_account),
             round_robin_cursor: scheduling.round_robin_cursor(),
-            availability: request.availability(),
+            eligibility: request.eligibility(),
         };
         let mut capacity_denied = false;
         let mut retry_after = None;
@@ -363,23 +364,18 @@ impl GrokAccountSessionSelector {
             .await;
     }
 
-    async fn persist_account_failure(
+    async fn persist_quota_failure(
         &self,
         session: &SelectedGrokSession,
-        availability: GrokCredentialAvailability,
-        reason: &'static str,
         observed_at: chrono::DateTime<Utc>,
     ) {
-        let update = |expected_revision| UpdateGrokCredentialState {
-            account_id: session.account_id().clone(),
-            expected_revision,
-            availability,
-            availability_reason: Some(reason.to_owned()),
-            observed_at,
-        };
         match self
             .repository
-            .update_state(&update(session.credential_revision()))
+            .update_quota_access(
+                session.account_id().clone(),
+                session.credential_revision(),
+                QuotaState::exhausted(QuotaEvidence::UsageLimitReached, observed_at.into(), None),
+            )
             .await
         {
             Ok(()) => return,
@@ -410,7 +406,11 @@ impl GrokAccountSessionSelector {
         };
         if let Err(error) = self
             .repository
-            .update_state(&update(current.account.revision()))
+            .update_quota_access(
+                session.account_id().clone(),
+                current.account.revision(),
+                QuotaState::exhausted(QuotaEvidence::UsageLimitReached, observed_at.into(), None),
+            )
             .await
         {
             tracing::warn!(
@@ -450,20 +450,15 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                 return;
             }
             let observed_at = Utc::now();
-            let persistent = match failure {
+            match failure {
                 GrokCredentialFailure::Unauthorized => {
                     self.record_runtime_cooldown(session, UNAUTHORIZED_COOLDOWN)
                         .await;
-                    return;
                 }
-                GrokCredentialFailure::QuotaExhausted => (
-                    GrokCredentialAvailability::QuotaExhausted,
-                    "upstream_quota_exhausted",
-                ),
-                GrokCredentialFailure::FreeQuotaExhausted => (
-                    GrokCredentialAvailability::QuotaExhausted,
-                    "upstream_free_quota_exhausted",
-                ),
+                GrokCredentialFailure::QuotaExhausted
+                | GrokCredentialFailure::FreeQuotaExhausted => {
+                    self.persist_quota_failure(session, observed_at).await;
+                }
                 // bare 402 没有结构化 quota code，不能证明账号额度耗尽：
                 // 只写短期账号级 runtime cooldown（TransientBackoff），
                 // 不持久化 QuotaExhausted（结构化 QuotaExhausted/FreeQuotaExhausted 走上面）。
@@ -472,7 +467,6 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                         .unwrap_or(DEFAULT_RATE_LIMIT_COOLDOWN)
                         .min(MAX_RATE_LIMIT_COOLDOWN);
                     self.record_runtime_cooldown(session, retry_after).await;
-                    return;
                 }
                 // xAI 免费模型额度按该模型滚动窗口恢复：限流写 model-scoped
                 // runtime cooldown（Redis 跨重启保留），不进入持久化账号状态，
@@ -485,7 +479,6 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                         bounded_cooldown(retry_after, MODEL_QUOTA_COOLDOWN, MAX_MODEL_COOLDOWN);
                     self.record_model_runtime_cooldown(session, upstream_model, retry_after)
                         .await;
-                    return;
                 }
                 GrokCredentialFailure::ModelAccessDenied {
                     upstream_model,
@@ -498,24 +491,18 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                     );
                     self.record_model_runtime_cooldown(session, upstream_model, retry_after)
                         .await;
-                    return;
                 }
                 GrokCredentialFailure::RateLimited { retry_after } => {
                     let retry_after = retry_after
                         .unwrap_or(DEFAULT_RATE_LIMIT_COOLDOWN)
                         .min(MAX_RATE_LIMIT_COOLDOWN);
                     self.record_runtime_cooldown(session, retry_after).await;
-                    return;
                 }
                 GrokCredentialFailure::StreamInterrupted => {
                     self.record_runtime_cooldown(session, STREAM_INTERRUPTION_COOLDOWN)
                         .await;
-                    return;
                 }
-            };
-            let (availability, reason) = persistent;
-            self.persist_account_failure(session, availability, reason, observed_at)
-                .await;
+            }
         })
     }
 
@@ -531,25 +518,22 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                 return;
             };
             let account = &current.account;
-            if account.revision() != session.credential_revision()
-                || !account.enabled()
-                || !matches!(
-                    account.availability(),
-                    AccountAvailability::Unknown | AccountAvailability::Expired
-                )
-            {
+            if account.revision() != session.credential_revision() || !account.enabled() {
                 return;
             }
-            if let Err(error) = self
-                .repository
-                .update_state(&UpdateGrokCredentialState {
-                    account_id: account.id().clone(),
-                    expected_revision: account.revision(),
-                    availability: GrokCredentialAvailability::Ready,
-                    availability_reason: None,
-                    observed_at: Utc::now(),
-                })
-                .await
+            let observed_at = Utc::now();
+            if account.credential_state() != CredentialState::Ready
+                && let Err(error) = self
+                    .repository
+                    .update_state(&UpdateGrokCredentialState {
+                        account_id: account.id().clone(),
+                        expected_revision: account.revision(),
+                        credential_state: CredentialState::Ready,
+                        error_reason: None,
+                        error_message: None,
+                        observed_at,
+                    })
+                    .await
             {
                 tracing::warn!(
                     account_id = %account.id(),
@@ -557,6 +541,24 @@ impl GrokSessionSelector for GrokAccountSessionSelector {
                     "xAI account state recovery after successful upstream response failed"
                 );
             }
+            // 已经发出的并发请求可能晚于耗尽事实成功返回；真实成功可以收敛
+            // 该事实，但 selector 不会为恢复探测而放行耗尽账号。
+            if account.quota().access() == QuotaAccessState::Exhausted
+                && let Err(error) = self
+                    .repository
+                    .update_quota_access(
+                        account.id().clone(),
+                        account.revision(),
+                        QuotaState::allowed(observed_at.into()),
+                    )
+                    .await
+            {
+                tracing::warn!(
+                    account_id = %account.id(),
+                    error = %error,
+                    "xAI quota recovery after successful upstream response failed"
+                );
+            }
         })
     }
 }
diff --git a/backend/crates/providers/xai/src/credential/types.rs b/backend/crates/providers/xai/src/credential/types.rs
index e1eb9448e..af1cbf535 100644
--- a/backend/crates/providers/xai/src/credential/types.rs
+++ b/backend/crates/providers/xai/src/credential/types.rs
@@ -4,7 +4,7 @@ use std::fmt;
 
 use chrono::{DateTime, Utc};
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialCasUpdate, CredentialRevision, LoadedCredential,
+    AccountErrorReason, CredentialCasUpdate, CredentialRevision, CredentialState, LoadedCredential,
     ProviderAccountId, ProviderAccountUpdate,
 };
 use gateway_core::provider_ports::ProviderLeaseGuard;
@@ -63,34 +63,6 @@ impl fmt::Debug for GrokAccountProfile {
     }
 }
 
-/// 与 `provider_accounts.availability` 一一对应的 xAI 状态。
-///
-/// 限流（429/滚动窗口）不进入持久化状态：由 `ProviderCooldownPort`（Redis 跨重启
-/// 保留）驱动调度排除，账号状态保持 `Ready`。
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-pub enum GrokCredentialAvailability {
-    Unknown,
-    Ready,
-    QuotaExhausted,
-    Expired,
-    Banned,
-    Invalid,
-}
-
-/// Grok 可用性语义翻入内核标准态的唯一汇入点。
-impl From<GrokCredentialAvailability> for AccountAvailability {
-    fn from(value: GrokCredentialAvailability) -> Self {
-        match value {
-            GrokCredentialAvailability::Unknown => Self::Unknown,
-            GrokCredentialAvailability::Ready => Self::Ready,
-            GrokCredentialAvailability::QuotaExhausted => Self::QuotaExhausted,
-            GrokCredentialAvailability::Expired => Self::Expired,
-            GrokCredentialAvailability::Banned => Self::Banned,
-            GrokCredentialAvailability::Invalid => Self::Invalid,
-        }
-    }
-}
-
 /// 创建一个明文 OAuth Provider account。
 pub struct CreateGrokCredential {
     pub account_id: ProviderAccountId,
@@ -98,8 +70,9 @@ pub struct CreateGrokCredential {
     pub secret: GrokOAuthSecret,
     pub account: GrokAccountProfile,
     pub enabled: bool,
-    pub initial_availability: GrokCredentialAvailability,
-    pub initial_availability_reason: Option<String>,
+    pub initial_credential_state: CredentialState,
+    pub initial_error_reason: Option<AccountErrorReason>,
+    pub initial_error_message: Option<String>,
 }
 
 impl fmt::Debug for CreateGrokCredential {
@@ -111,7 +84,7 @@ impl fmt::Debug for CreateGrokCredential {
             .field("secret", &"[REDACTED]")
             .field("account", &self.account)
             .field("enabled", &self.enabled)
-            .field("initial_availability", &self.initial_availability)
+            .field("initial_credential_state", &self.initial_credential_state)
             .finish_non_exhaustive()
     }
 }
@@ -235,8 +208,9 @@ impl fmt::Debug for RotateGrokCredential {
 pub struct UpdateGrokCredentialState {
     pub account_id: ProviderAccountId,
     pub expected_revision: CredentialRevision,
-    pub availability: GrokCredentialAvailability,
-    pub availability_reason: Option<String>,
+    pub credential_state: CredentialState,
+    pub error_reason: Option<AccountErrorReason>,
+    pub error_message: Option<String>,
     pub observed_at: DateTime<Utc>,
 }
 
diff --git a/backend/crates/providers/xai/src/lib.rs b/backend/crates/providers/xai/src/lib.rs
index 8247c3c56..fa5084907 100644
--- a/backend/crates/providers/xai/src/lib.rs
+++ b/backend/crates/providers/xai/src/lib.rs
@@ -30,25 +30,25 @@ pub use credential::{
     FailClosedTokenVerifier, FailureClass, FormField, FormValue, GROK_FREE_ROLLING_WINDOW_SECONDS,
     GrokAccountExport, GrokAccountProfile, GrokAccountSessionSelector, GrokBillingPresentation,
     GrokCatalogCache, GrokCatalogCacheError, GrokCatalogScope, GrokCredentialAdmin,
-    GrokCredentialAvailability, GrokCredentialCatalogCache, GrokCredentialCatalogError,
-    GrokCredentialCatalogSeed, GrokCredentialCatalogService, GrokCredentialLifecycle,
-    GrokCredentialQuotaService, GrokCredentialRecord, GrokCredentialRecovery,
-    GrokCredentialRecoveryOutcome, GrokCredentialRefreshError, GrokCredentialRefreshOutcome,
-    GrokCredentialRefreshService, GrokCredentialRefresher, GrokCredentialRepository,
-    GrokCredentialRepositoryError, GrokOAuthClient, GrokOAuthConfig, GrokOAuthImportCandidate,
-    GrokOAuthImportDocument, GrokOAuthImportEntry, GrokOAuthImportError, GrokOAuthImportMetadata,
-    GrokOAuthImportTokens, GrokOAuthRefreshClient, GrokOAuthSecret, GrokPlanCatalog,
-    GrokQuotaError, GrokQuotaPeriodKind, GrokQuotaSnapshot, GrokRefreshFailure, GrokRefreshTokens,
-    HttpHeader, HttpMethod, OAuthError, OAuthErrorCode, OAuthHttpRequest, OAuthHttpResponse,
-    OAuthHttpTransport, OAuthOperation, OAuthPrincipal, OFFICIAL_CLIENT_ID, OFFICIAL_ISSUER,
-    OFFICIAL_REDIRECT_URI, OFFICIAL_SCOPES, PendingAuthorization, Pkce,
-    PreparedGrokCredentialRotation, PreparedGrokCredentialRotationGuard, ProtocolViolation,
-    RedirectUriAllowlist, RefreshTokenGrant, RefreshedTokenSet, ReqwestOidcTokenVerifier,
-    RotateGrokCredential, RotateManagedGrokCredential, SecretValue, TokenCandidate,
-    TokenVerificationContext, TokenVerifier, TransportFailure, TransportFailureKind,
-    TransportFuture, UpdateGrokCredentialState, VerificationEvidence, VerificationFailure,
-    VerificationFlow, VerificationFuture, VerificationMethod, VerifiedGrokAccount,
-    VerifiedTokenSet, parse_oauth_error, parse_refresh_success,
+    GrokCredentialCatalogCache, GrokCredentialCatalogError, GrokCredentialCatalogSeed,
+    GrokCredentialCatalogService, GrokCredentialLifecycle, GrokCredentialQuotaService,
+    GrokCredentialRecord, GrokCredentialRecovery, GrokCredentialRecoveryOutcome,
+    GrokCredentialRefreshError, GrokCredentialRefreshOutcome, GrokCredentialRefreshService,
+    GrokCredentialRefresher, GrokCredentialRepository, GrokCredentialRepositoryError,
+    GrokOAuthClient, GrokOAuthConfig, GrokOAuthImportCandidate, GrokOAuthImportDocument,
+    GrokOAuthImportEntry, GrokOAuthImportError, GrokOAuthImportMetadata, GrokOAuthImportTokens,
+    GrokOAuthRefreshClient, GrokOAuthSecret, GrokPlanCatalog, GrokQuotaError, GrokQuotaPeriodKind,
+    GrokQuotaSnapshot, GrokRefreshFailure, GrokRefreshTokens, HttpHeader, HttpMethod, OAuthError,
+    OAuthErrorCode, OAuthHttpRequest, OAuthHttpResponse, OAuthHttpTransport, OAuthOperation,
+    OAuthPrincipal, OFFICIAL_CLIENT_ID, OFFICIAL_ISSUER, OFFICIAL_REDIRECT_URI, OFFICIAL_SCOPES,
+    PendingAuthorization, Pkce, PreparedGrokCredentialRotation,
+    PreparedGrokCredentialRotationGuard, ProtocolViolation, RedirectUriAllowlist,
+    RefreshTokenGrant, RefreshedTokenSet, ReqwestOidcTokenVerifier, RotateGrokCredential,
+    RotateManagedGrokCredential, SecretValue, TokenCandidate, TokenVerificationContext,
+    TokenVerifier, TransportFailure, TransportFailureKind, TransportFuture,
+    UpdateGrokCredentialState, VerificationEvidence, VerificationFailure, VerificationFlow,
+    VerificationFuture, VerificationMethod, VerifiedGrokAccount, VerifiedTokenSet,
+    parse_oauth_error, parse_refresh_success,
 };
 pub use provider::GrokBuildProvider;
 pub use transport::profile::{
diff --git a/backend/crates/providers/xai/src/provider.rs b/backend/crates/providers/xai/src/provider.rs
index fe9201eb9..edc11babf 100644
--- a/backend/crates/providers/xai/src/provider.rs
+++ b/backend/crates/providers/xai/src/provider.rs
@@ -8,8 +8,8 @@ use async_trait::async_trait;
 use futures::{StreamExt, future::BoxFuture};
 use gateway_core::engine::continuation::ContinuationBinding;
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountAvailabilityPolicy, AccountFeedbackStats, ProviderAccount,
-    ProviderAccountId, ProviderAccountStore,
+    AccountEligibilityPolicy, AccountFeedbackStats, ProviderAccount, ProviderAccountId,
+    ProviderAccountStore,
 };
 use gateway_core::engine::provider::{
     EventStream, Provider, ProviderCallMetadata, ProviderCatalogGeneration,
@@ -392,10 +392,10 @@ async fn select_grok_session(
         context.account_selection_policy(),
         context.deadline(),
     )
-    .with_availability_policy(if context.is_diagnostic_required_account() {
-        AccountAvailabilityPolicy::BypassForDiagnostic
+    .with_eligibility_policy(if context.is_diagnostic_required_account() {
+        AccountEligibilityPolicy::BypassForDiagnostic
     } else {
-        AccountAvailabilityPolicy::Enforce
+        AccountEligibilityPolicy::Enforce
     })
     .with_affinity(affinity);
     let selection_deadline = remaining(context.deadline())
@@ -1981,7 +1981,8 @@ const OAUTH_REFRESH_INTERVAL: Duration = Duration::from_secs(30);
 const QUOTA_CATALOG_INTERVAL: Duration = Duration::from_secs(5 * 60);
 // grok2api 对 Free/未知额度耗尽采用 24 小时恢复探测；当前公共账号状态没有
 // 独立的 paid period-end 字段，因此 Build 账号统一使用同一保守下限。
-const QUOTA_PERIODIC_REFRESH_MIN_INTERVAL: Duration = Duration::from_secs(24 * 60 * 60);
+const EXHAUSTED_QUOTA_FALLBACK_RECHECK_INTERVAL: Duration = Duration::from_secs(24 * 60 * 60);
+const EXHAUSTED_QUOTA_REFRESH_RETRY_INTERVAL: Duration = QUOTA_CATALOG_INTERVAL;
 const CLI_RELEASE_WORKER_OWNER: &str = "xai-cli-release";
 
 pub(crate) fn worker_contributions(
@@ -2175,7 +2176,8 @@ impl XaiQuotaCatalogTask {
                 let due = last_periodic_refresh_at
                     .get(account.id())
                     .is_none_or(|last| {
-                        now.saturating_duration_since(*last) >= QUOTA_PERIODIC_REFRESH_MIN_INTERVAL
+                        now.saturating_duration_since(*last)
+                            >= EXHAUSTED_QUOTA_REFRESH_RETRY_INTERVAL
                     });
                 if due {
                     last_periodic_refresh_at.insert(account.id().clone(), now);
@@ -2191,5 +2193,7 @@ fn eligible_quota_worker_account(account: &ProviderAccount, now: SystemTime) ->
         && account
             .access_token_expires_at()
             .is_some_and(|expires_at| expires_at > now)
-        && account.availability() == AccountAvailability::QuotaExhausted
+        && account
+            .quota()
+            .exhaustion_refresh_due(now, EXHAUSTED_QUOTA_FALLBACK_RECHECK_INTERVAL)
 }
diff --git a/backend/crates/providers/xai/src/transport/session.rs b/backend/crates/providers/xai/src/transport/session.rs
index 97e0bebdf..e2b6b644a 100644
--- a/backend/crates/providers/xai/src/transport/session.rs
+++ b/backend/crates/providers/xai/src/transport/session.rs
@@ -5,7 +5,7 @@ use std::pin::Pin;
 use std::time::{Duration, SystemTime};
 
 use gateway_core::engine::credential::{
-    AccountAvailabilityPolicy, AccountSelectionPolicy, CredentialRevision, ProviderAccountId,
+    AccountEligibilityPolicy, AccountSelectionPolicy, CredentialRevision, ProviderAccountId,
 };
 use gateway_core::engine::provider::ProviderResource;
 use gateway_core::routing::UpstreamModelId;
@@ -210,7 +210,7 @@ pub struct GrokSessionSelection {
     excluded_accounts: BTreeSet<ProviderAccountId>,
     required_account: Option<ProviderAccountId>,
     account_selection_policy: AccountSelectionPolicy,
-    availability: AccountAvailabilityPolicy,
+    eligibility: AccountEligibilityPolicy,
     affinity: Option<GrokSessionAffinityKey>,
     deadline: SystemTime,
 }
@@ -230,7 +230,7 @@ impl GrokSessionSelection {
             excluded_accounts,
             required_account,
             account_selection_policy,
-            availability: AccountAvailabilityPolicy::Enforce,
+            eligibility: AccountEligibilityPolicy::Enforce,
             affinity: None,
             deadline,
         }
@@ -245,11 +245,11 @@ impl GrokSessionSelection {
 
     /// 为固定账号的管理端诊断指定本地可用性判定策略。
     #[must_use]
-    pub(crate) const fn with_availability_policy(
+    pub(crate) const fn with_eligibility_policy(
         mut self,
-        availability: AccountAvailabilityPolicy,
+        eligibility: AccountEligibilityPolicy,
     ) -> Self {
-        self.availability = availability;
+        self.eligibility = eligibility;
         self
     }
 
@@ -278,8 +278,8 @@ impl GrokSessionSelection {
     }
 
     #[must_use]
-    pub const fn availability(&self) -> AccountAvailabilityPolicy {
-        self.availability
+    pub const fn eligibility(&self) -> AccountEligibilityPolicy {
+        self.eligibility
     }
 
     /// 返回不含原始客户端会话值的账号亲和键。
diff --git a/backend/crates/providers/xai/tests/admin.rs b/backend/crates/providers/xai/tests/admin.rs
index 1c72dd73b..c7eed7f06 100644
--- a/backend/crates/providers/xai/tests/admin.rs
+++ b/backend/crates/providers/xai/tests/admin.rs
@@ -471,10 +471,11 @@ fn account_record(account: &ProviderAccount) -> AccountRecord {
         access_token_expires_at: account.access_token_expires_at().map(DateTime::<Utc>::from),
         next_refresh_at: account.next_refresh_at().map(DateTime::<Utc>::from),
         enabled: account.enabled(),
-        availability: account.availability(),
-        availability_observed_at: now,
-        last_error_message: None,
-        quota_observed_at: None,
+        credential_state: account.credential_state(),
+        credential_observed_at: now,
+        quota: account.quota(),
+        last_error_reason: account.last_error_reason(),
+        last_error_message: account.last_error_message().map(str::to_owned),
         created_at: now,
         updated_at: now,
     }
@@ -503,7 +504,7 @@ impl ProviderLeasePort for TestLeases {
                             last_started_at: None,
                             quota_reset_at: None,
                             quota_remaining_rank: None,
-                            quota_limit_reached: false,
+                            rate_limited_until: None,
                             failure_rate_basis_points: None,
                             first_output_latency_ms: None,
                         },
diff --git a/backend/crates/providers/xai/tests/credential/catalog.rs b/backend/crates/providers/xai/tests/credential/catalog.rs
index 6d0ba6290..ea77c04a3 100644
--- a/backend/crates/providers/xai/tests/credential/catalog.rs
+++ b/backend/crates/providers/xai/tests/credential/catalog.rs
@@ -5,9 +5,9 @@ use std::time::{Duration, SystemTime};
 
 use futures::future::{BoxFuture, join_all};
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasUpdate, CredentialRevision,
+    AccountStateChange, CredentialCasUpdate, CredentialRevision, CredentialState,
     OpaqueProviderData, ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate,
-    QuotaObservation,
+    QuotaAccessChange, QuotaEvidence, QuotaObservation, QuotaState,
 };
 use gateway_core::provider_ports::{
     ProviderCatalogCacheKey, ProviderCatalogCachePort, ProviderStoreError,
@@ -200,14 +200,15 @@ async fn repository_with_accounts(
 async fn set_account_state(
     store: &MemoryProviderAccountStore,
     id: &ProviderAccountId,
-    availability: AccountAvailability,
+    credential_state: CredentialState,
 ) {
     store
         .apply_state_change(AccountStateChange {
             message: None,
             account_id: id.clone(),
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            availability,
+            credential_state,
+            error_reason: credential_state.error_reason(),
             observed_at: SystemTime::now(),
         })
         .await
@@ -485,12 +486,10 @@ async fn quota_exhausted_account_remains_eligible_for_catalog_discovery() {
         repository_with_accounts(&[("quota-exhausted", "subject-quota-exhausted")]).await;
     let id = account_id("quota-exhausted");
     store
-        .apply_state_change(AccountStateChange {
-            message: None,
+        .apply_quota_access(QuotaAccessChange {
             account_id: id,
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            availability: AccountAvailability::QuotaExhausted,
-            observed_at: SystemTime::now(),
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, SystemTime::now(), None),
         })
         .await
         .expect("mark quota exhausted");
@@ -662,7 +661,7 @@ async fn quota_refresh_persists_dynamic_provider_document_and_projects_known_fie
         .expect("read persisted quota")
         .pop()
         .expect("quota exists");
-    let document = persisted.quota.expect("provider quota");
+    let document = persisted.quota;
 
     assert_eq!(transport.calls.load(Ordering::SeqCst), 1);
     assert_eq!(snapshot.billing().used_percent(), Some(37.5));
@@ -683,33 +682,18 @@ async fn quota_refresh_persists_dynamic_provider_document_and_projects_known_fie
 }
 
 #[tokio::test]
-async fn recovered_quota_refresh_releases_existing_quota_isolation() {
-    for (suffix, availability) in [
-        ("recover-quota", AccountAvailability::QuotaExhausted),
-        ("recover-ready", AccountAvailability::Ready),
-    ] {
-        let (store, repository) = repository_with_accounts(&[(suffix, suffix)]).await;
-        let id = account_id(suffix);
-        set_account_state(&store, &id, availability).await;
-        crate::support::grok_quota_service(
-            repository,
-            QueueBillingTransport::success(br#"{"config":{"creditUsagePercent":25}}"#),
-        )
-        .refresh_account(&id)
-        .await
-        .expect("refresh recovered quota");
-
-        let account = store.account(&id).expect("account");
-        assert_eq!(account.availability(), AccountAvailability::Ready);
-    }
-}
-
-#[tokio::test]
-async fn authoritative_exhaustion_preserves_quota_exhausted_state() {
+async fn billing_percent_does_not_rewrite_quota_access_fact() {
     let (store, repository) =
         repository_with_accounts(&[("still-exhausted", "still-exhausted")]).await;
     let id = account_id("still-exhausted");
-    set_account_state(&store, &id, AccountAvailability::QuotaExhausted).await;
+    store
+        .apply_quota_access(QuotaAccessChange {
+            account_id: id.clone(),
+            expected_revision: CredentialRevision::new(1).expect("revision"),
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, SystemTime::now(), None),
+        })
+        .await
+        .expect("mark quota exhausted");
 
     crate::support::grok_quota_service(
         repository,
@@ -720,21 +704,75 @@ async fn authoritative_exhaustion_preserves_quota_exhausted_state() {
     .expect("refresh exhausted quota");
 
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::QuotaExhausted
+        store.account(&id).expect("account").quota().access(),
+        gateway_core::engine::credential::QuotaAccessState::Exhausted
     );
 }
 
+#[tokio::test]
+async fn authoritative_billing_refresh_clears_existing_quota_exhaustion() {
+    let (store, repository) =
+        repository_with_accounts(&[("recovered-quota", "recovered-quota")]).await;
+    let id = account_id("recovered-quota");
+    store
+        .apply_quota_access(QuotaAccessChange {
+            account_id: id.clone(),
+            expected_revision: CredentialRevision::new(1).expect("revision"),
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, SystemTime::now(), None),
+        })
+        .await
+        .expect("mark quota exhausted");
+
+    crate::support::grok_quota_service(
+        repository,
+        QueueBillingTransport::success(
+            br#"{"config":{"creditUsagePercent":12.5,"currentPeriod":{"type":"USAGE_PERIOD_TYPE_WEEKLY","start":"2026-07-15T00:00:00Z","end":"2099-07-22T00:00:00Z"}}}"#,
+        ),
+    )
+    .refresh_account(&id)
+    .await
+    .expect("refresh recovered quota");
+
+    assert_eq!(
+        store.account(&id).expect("account").quota().access(),
+        gateway_core::engine::credential::QuotaAccessState::Allowed
+    );
+}
+
+#[tokio::test]
+async fn full_usage_display_does_not_invent_quota_exhaustion() {
+    let (store, repository) =
+        repository_with_accounts(&[("exhausted-quota", "exhausted-quota")]).await;
+    let id = account_id("exhausted-quota");
+
+    crate::support::grok_quota_service(
+        repository,
+        QueueBillingTransport::success(
+            br#"{"config":{"creditUsagePercent":100,"currentPeriod":{"type":"USAGE_PERIOD_TYPE_WEEKLY","start":"2026-07-15T00:00:00Z","end":"2099-07-22T00:00:00Z"}}}"#,
+        ),
+    )
+    .refresh_account(&id)
+    .await
+    .expect("refresh exhausted quota");
+
+    let quota = store.account(&id).expect("account").quota();
+    assert_eq!(
+        quota.access(),
+        gateway_core::engine::credential::QuotaAccessState::Unknown
+    );
+    assert!(quota.reset_at().is_none());
+}
+
 #[tokio::test]
 async fn recovered_quota_does_not_clear_terminal_account_states() {
-    for (suffix, availability) in [
-        ("keep-banned", AccountAvailability::Banned),
-        ("keep-expired", AccountAvailability::Expired),
-        ("keep-invalid", AccountAvailability::Invalid),
+    for (suffix, credential_state) in [
+        ("keep-banned", CredentialState::Banned),
+        ("keep-expired", CredentialState::Expired),
+        ("keep-invalid", CredentialState::Invalid),
     ] {
         let (store, repository) = repository_with_accounts(&[(suffix, suffix)]).await;
         let id = account_id(suffix);
-        set_account_state(&store, &id, availability).await;
+        set_account_state(&store, &id, credential_state).await;
         crate::support::grok_quota_service(
             repository,
             QueueBillingTransport::success(br#"{"config":{"creditUsagePercent":10}}"#),
@@ -744,14 +782,14 @@ async fn recovered_quota_does_not_clear_terminal_account_states() {
         .expect("refresh terminal account quota");
 
         assert_eq!(
-            store.account(&id).expect("account").availability(),
-            availability
+            store.account(&id).expect("account").credential_state(),
+            credential_state
         );
     }
 }
 
 #[tokio::test]
-async fn quota_refresh_preserves_ready_availability_across_concurrent_state_write() {
+async fn quota_refresh_preserves_ready_credential_state_across_concurrent_write() {
     let (store, repository) = repository_with_accounts(&[("new-cooldown", "new-cooldown")]).await;
     let id = account_id("new-cooldown");
     let transport = Arc::new(MutatingBillingTransport {
@@ -760,7 +798,8 @@ async fn quota_refresh_preserves_ready_availability_across_concurrent_state_writ
             message: None,
             account_id: id.clone(),
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            availability: AccountAvailability::Ready,
+            credential_state: CredentialState::Ready,
+            error_reason: None,
             observed_at: SystemTime::now(),
         }))),
         body: br#"{"config":{"creditUsagePercent":10}}"#.to_vec(),
@@ -772,7 +811,7 @@ async fn quota_refresh_preserves_ready_availability_across_concurrent_state_writ
         .expect("refresh around concurrent state write");
 
     let account = store.account(&id).expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
 }
 
 #[tokio::test]
@@ -860,12 +899,48 @@ async fn quota_projection_preserves_unknown_period_for_dynamic_duration_fallback
     );
 }
 
+#[tokio::test]
+async fn expired_billing_window_does_not_participate_in_scheduling_rank() {
+    let (store, repository) =
+        repository_with_accounts(&[("expired-billing", "expired-billing")]).await;
+    let id = account_id("expired-billing");
+    let account = store.account(&id).expect("account");
+    let service = crate::support::grok_quota_service(
+        repository,
+        QueueBillingTransport::success(
+            br#"{"config":{"creditUsagePercent":25,"currentPeriod":{"type":"USAGE_PERIOD_TYPE_WEEKLY","start":"2000-01-01T00:00:00Z","end":"2000-01-08T00:00:00Z"}}}"#,
+        ),
+    );
+
+    service
+        .refresh_account(&id)
+        .await
+        .expect("refresh expired billing window");
+
+    assert_eq!(service.scheduling_signals(&account), None);
+    assert_eq!(
+        store
+            .account(&id)
+            .expect("refreshed account")
+            .quota()
+            .access(),
+        gateway_core::engine::credential::QuotaAccessState::Unknown
+    );
+}
+
 #[tokio::test]
 async fn non_authoritative_quota_refresh_does_not_clear_existing_quota_exhaustion() {
     let (store, repository) =
         repository_with_accounts(&[("free-quota", "subject-free-quota")]).await;
     let id = account_id("free-quota");
-    set_account_state(&store, &id, AccountAvailability::QuotaExhausted).await;
+    store
+        .apply_quota_access(QuotaAccessChange {
+            account_id: id.clone(),
+            expected_revision: CredentialRevision::new(1).expect("revision"),
+            state: QuotaState::exhausted(QuotaEvidence::ProviderDenied, SystemTime::now(), None),
+        })
+        .await
+        .expect("mark quota exhausted");
     let transport = QueueBillingTransport::success(
         br#"{"config":{"currentPeriod":{"type":"USAGE_PERIOD_TYPE_WEEKLY","start":"2026-07-15T00:00:00Z","end":"2026-07-22T00:00:00Z"},"onDemandCap":{"val":0},"onDemandUsed":{"val":0},"prepaidBalance":{"val":0}}}"#,
     );
@@ -876,8 +951,8 @@ async fn non_authoritative_quota_refresh_does_not_clear_existing_quota_exhaustio
 
     assert!(!snapshot.billing().has_authoritative_quota());
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::QuotaExhausted
+        store.account(&id).expect("account").quota().access(),
+        gateway_core::engine::credential::QuotaAccessState::Exhausted
     );
 }
 
@@ -920,9 +995,9 @@ async fn quota_read_rejects_corrupt_provider_document() {
         .compare_and_swap_quota(QuotaObservation {
             account_id: account_id("corrupt"),
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            quota: Some(OpaqueProviderData::new(document)),
-            observed_at: Some(SystemTime::now()),
-            limit_reached: None,
+            quota: OpaqueProviderData::new(document),
+            observed_at: SystemTime::now(),
+            state: QuotaState::unknown(),
         })
         .await
         .expect("seed corrupt quota");
@@ -975,8 +1050,7 @@ async fn failed_quota_refresh_does_not_replace_last_good_observation() {
         .expect("read quota")
         .pop()
         .expect("quota remains")
-        .quota
-        .expect("provider document");
+        .quota;
     assert_eq!(
         persisted.expose_to_provider()["config"]["creditUsagePercent"].as_f64(),
         Some(10.0),
diff --git a/backend/crates/providers/xai/tests/credential/client.rs b/backend/crates/providers/xai/tests/credential/client.rs
index 0c46d94a2..a531bb858 100644
--- a/backend/crates/providers/xai/tests/credential/client.rs
+++ b/backend/crates/providers/xai/tests/credential/client.rs
@@ -4,7 +4,7 @@ use std::collections::VecDeque;
 use std::future::ready;
 use std::sync::{Arc, Mutex};
 
-use gateway_core::engine::credential::AccountAvailability;
+use gateway_core::engine::credential::CredentialState;
 use provider_xai::{
     AuthorizationCallback, FailClosedTokenVerifier, FailureClass, FormValue, GrokCredentialAdmin,
     GrokOAuthClient, GrokOAuthConfig, GrokOAuthImportCandidate, GrokOAuthImportMetadata,
@@ -128,7 +128,7 @@ async fn credential_import_should_require_exact_metadata_and_official_userinfo()
             enabled: true,
         })
         .expect("Provider projects verified token lifetime");
-    assert_eq!(prepared.account.availability(), AccountAvailability::Ready);
+    assert_eq!(prepared.account.credential_state(), CredentialState::Ready);
     assert!(prepared.account.next_refresh_at().is_none());
     assert!(
         prepared
diff --git a/backend/crates/providers/xai/tests/credential/contract.rs b/backend/crates/providers/xai/tests/credential/contract.rs
index 43a3d9d83..515f571f9 100644
--- a/backend/crates/providers/xai/tests/credential/contract.rs
+++ b/backend/crates/providers/xai/tests/credential/contract.rs
@@ -2,15 +2,14 @@ use std::sync::Arc;
 
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialCasOutcome, CredentialRevision, NewProviderAccount,
-    PlaintextCredential, ProviderAccount, ProviderAccountStore,
+    AccountErrorReason, CredentialCasOutcome, CredentialRevision, CredentialState,
+    NewProviderAccount, PlaintextCredential, ProviderAccount, ProviderAccountStore,
 };
 use gateway_core::error::StoreErrorKind;
 use gateway_core::routing::ProviderKind;
 use provider_xai::{
-    GrokCredentialAdmin, GrokCredentialAvailability, GrokCredentialRepository,
-    GrokCredentialRepositoryError, GrokOAuthSecret, RotateManagedGrokCredential, SecretValue,
-    UpdateGrokCredentialState,
+    GrokCredentialAdmin, GrokCredentialRepository, GrokCredentialRepositoryError, GrokOAuthSecret,
+    RotateManagedGrokCredential, SecretValue, UpdateGrokCredentialState,
 };
 
 use crate::support::{
@@ -219,14 +218,15 @@ async fn state_update_uses_credential_revision_fence() {
         .update_state(&UpdateGrokCredentialState {
             account_id: input.account_id.clone(),
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            availability: GrokCredentialAvailability::Ready,
-            availability_reason: Some("upstream_rate_limited".to_owned()),
+            credential_state: CredentialState::Ready,
+            error_reason: None,
+            error_message: Some("upstream_rate_limited".to_owned()),
             observed_at: Utc::now(),
         })
         .await
         .expect("state update");
     let account = store.account(&input.account_id).expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
 }
 
 #[tokio::test]
@@ -239,16 +239,20 @@ async fn terminal_state_without_upstream_message_uses_stable_error_reason() {
         .update_state(&UpdateGrokCredentialState {
             account_id: input.account_id.clone(),
             expected_revision: CredentialRevision::new(1).expect("revision"),
-            availability: GrokCredentialAvailability::Banned,
-            availability_reason: None,
+            credential_state: CredentialState::Banned,
+            error_reason: Some(AccountErrorReason::AccountBanned),
+            error_message: None,
             observed_at: Utc::now(),
         })
         .await
         .expect("state update");
 
     assert_eq!(
-        store.last_error_message(&input.account_id).as_deref(),
-        Some("account_banned")
+        store
+            .account(&input.account_id)
+            .expect("account")
+            .last_error_reason(),
+        Some(AccountErrorReason::AccountBanned)
     );
 }
 
diff --git a/backend/crates/providers/xai/tests/credential/refresh.rs b/backend/crates/providers/xai/tests/credential/refresh.rs
index 23867cd53..69446604b 100644
--- a/backend/crates/providers/xai/tests/credential/refresh.rs
+++ b/backend/crates/providers/xai/tests/credential/refresh.rs
@@ -7,7 +7,7 @@ use std::time::{Duration, SystemTime};
 use async_trait::async_trait;
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAvailability, CredentialCasOutcome, CredentialCasUpdate, CredentialRevision,
+    CredentialCasOutcome, CredentialCasUpdate, CredentialRevision, CredentialState,
     ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate,
 };
 use gateway_core::provider_ports::{
@@ -514,8 +514,8 @@ async fn unauthorized_recovery_marks_a_permanently_rejected_refresh_expired() {
 
     assert_eq!(outcome, GrokCredentialRecoveryOutcome::Rejected);
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::Expired
+        store.account(&id).expect("account").credential_state(),
+        CredentialState::Expired
     );
     assert_eq!(
         store.last_error_message(&id).as_deref(),
@@ -664,8 +664,8 @@ async fn invalid_grant_marks_account_expired() {
         fixture(input, [Err(GrokRefreshFailure::InvalidGrant)], true).await;
     service.refresh_due().await.expect("refresh");
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::Expired
+        store.account(&id).expect("account").credential_state(),
+        CredentialState::Expired
     );
 }
 
@@ -676,8 +676,8 @@ async fn banned_failure_marks_account_banned() {
     let (store, _, _, service) = fixture(input, [Err(GrokRefreshFailure::Banned)], true).await;
     service.refresh_due().await.expect("refresh");
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::Banned
+        store.account(&id).expect("account").credential_state(),
+        CredentialState::Banned
     );
     assert_eq!(
         store.last_error_message(&id).as_deref(),
@@ -704,8 +704,8 @@ async fn ambiguous_refresh_applies_bounded_oauth_backoff() {
         [GrokCredentialRefreshOutcome::Ambiguous { account_id }] if account_id == &id
     ));
     assert_eq!(
-        store.account(&id).expect("account").availability(),
-        AccountAvailability::Unknown
+        store.account(&id).expect("account").credential_state(),
+        CredentialState::Unknown
     );
     let account = store.account(&id).expect("account");
     assert_eq!(account.revision().get(), 2);
@@ -736,7 +736,7 @@ async fn pre_send_transient_failure_applies_bounded_oauth_backoff() {
     let (store, _, _, service) = fixture(input, [Err(GrokRefreshFailure::Transient)], true).await;
     service.refresh_due().await.expect("refresh");
     let account = store.account(&id).expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Unknown);
+    assert_eq!(account.credential_state(), CredentialState::Unknown);
     assert_eq!(account.revision().get(), 2);
     assert!(
         account
@@ -908,8 +908,11 @@ async fn recovery_window_exhaustion_marks_account_expired_without_token_exchange
         [GrokCredentialRefreshOutcome::Invalidated { account_id }] if account_id == &id
     ));
     assert_eq!(
-        store.account(&id).expect("expired account").availability(),
-        AccountAvailability::Expired
+        store
+            .account(&id)
+            .expect("expired account")
+            .credential_state(),
+        CredentialState::Expired
     );
     assert_eq!(refresher.prepare_calls.load(Ordering::SeqCst), 1);
     assert_eq!(refresher.responses.lock().expect("queue").len(), 1);
diff --git a/backend/crates/providers/xai/tests/credential/selector.rs b/backend/crates/providers/xai/tests/credential/selector.rs
index 8b013a384..3a6b749d2 100644
--- a/backend/crates/providers/xai/tests/credential/selector.rs
+++ b/backend/crates/providers/xai/tests/credential/selector.rs
@@ -4,10 +4,10 @@ use std::time::{Duration, SystemTime};
 
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAttemptFeedback, AccountAvailability, AccountFeedbackStats, AccountRuntimeSignals,
-    AccountSelectionPolicy, CredentialCasOutcome, CredentialRevision, OpaqueProviderData,
-    ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate, QuotaObservation,
-    QuotaWriteOutcome, RotationStrategy,
+    AccountAttemptFeedback, AccountFeedbackStats, AccountRuntimeSignals, AccountSelectionPolicy,
+    CredentialCasOutcome, CredentialRevision, CredentialState, OpaqueProviderData,
+    ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate, QuotaAccessState,
+    QuotaObservation, QuotaState, QuotaWriteOutcome, RotationStrategy,
 };
 use gateway_core::provider_ports::{
     ProviderCooldownPort, ProviderCooldownScope, ProviderLeaseAcquisition, ProviderLeasePort,
@@ -17,10 +17,10 @@ use gateway_core::routing::UpstreamModelId;
 use provider_xai::{
     GrokAccountSessionSelector, GrokBillingRequest, GrokBillingTransport,
     GrokBillingTransportError, GrokBillingTransportErrorKind, GrokBillingTransportFuture,
-    GrokCatalogScope, GrokCredentialAdmin, GrokCredentialAvailability, GrokCredentialCatalogCache,
-    GrokCredentialCatalogSeed, GrokCredentialFailure, GrokCredentialRepository, GrokPlanCatalog,
-    GrokSessionSelection, GrokSessionSelector, GrokSessionSelectorError,
-    RotateManagedGrokCredential, UpdateGrokCredentialState,
+    GrokCatalogScope, GrokCredentialAdmin, GrokCredentialCatalogCache, GrokCredentialCatalogSeed,
+    GrokCredentialFailure, GrokCredentialRepository, GrokPlanCatalog, GrokSessionSelection,
+    GrokSessionSelector, GrokSessionSelectorError, RotateManagedGrokCredential,
+    UpdateGrokCredentialState,
 };
 
 use crate::support::{
@@ -108,8 +108,9 @@ impl SelectorFixture {
                 .update_state(&UpdateGrokCredentialState {
                     account_id: input.account_id.clone(),
                     expected_revision: CredentialRevision::new(1).expect("revision"),
-                    availability: GrokCredentialAvailability::Ready,
-                    availability_reason: None,
+                    credential_state: CredentialState::Ready,
+                    error_reason: None,
+                    error_message: None,
                     observed_at: Utc::now(),
                 })
                 .await
@@ -131,7 +132,7 @@ impl SelectorFixture {
                     last_started_at: None,
                     quota_reset_at: None,
                     quota_remaining_rank: None,
-                    quota_limit_reached: false,
+                    rate_limited_until: None,
                     failure_rate_basis_points: None,
                     first_output_latency_ms: None,
                 },
@@ -241,11 +242,9 @@ impl SelectorFixture {
             .compare_and_swap_quota(QuotaObservation {
                 account_id: id.clone(),
                 expected_revision: CredentialRevision::new(1).expect("revision"),
-                quota: Some(OpaqueProviderData::new(
-                    document.as_object().expect("quota object").clone(),
-                )),
-                observed_at: Some(SystemTime::now()),
-                limit_reached: None,
+                quota: OpaqueProviderData::new(document.as_object().expect("quota object").clone()),
+                observed_at: SystemTime::now(),
+                state: QuotaState::unknown(),
             })
             .await
             .expect("persist quota");
@@ -305,16 +304,20 @@ async fn unauthorized_feedback_records_runtime_cooldown_without_persisting_accou
             .store
             .account(&selected)
             .expect("selected")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
     let other = [account_id("feedback-a"), account_id("feedback-b")]
         .into_iter()
         .find(|id| id != &selected)
         .expect("other account");
     assert_eq!(
-        fixture.store.account(&other).expect("other").availability(),
-        AccountAvailability::Ready
+        fixture
+            .store
+            .account(&other)
+            .expect("other")
+            .credential_state(),
+        CredentialState::Ready
     );
     assert!(
         fixture
@@ -379,7 +382,7 @@ async fn account_scoped_cooldown_survives_credential_rotation() {
     ));
     let account = fixture.store.account(&id).expect("rotated account");
     assert_eq!(account.revision().get(), 2);
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
 }
 
 #[tokio::test]
@@ -401,7 +404,7 @@ async fn rate_limit_feedback_persists_the_grok2api_cooldown_state() {
         )
         .await;
     let account = fixture.store.account(&selected).expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
     assert!(
         fixture
             .cooldowns
@@ -440,7 +443,7 @@ async fn successful_request_clears_the_persisted_cooldown_state() {
         .store
         .account(session.account_id())
         .expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
 }
 
 #[tokio::test]
@@ -469,8 +472,8 @@ async fn payment_required_feedback_writes_short_account_cooldown_without_persist
             .store
             .account(&selected)
             .expect("selected account")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
     assert!(
         fixture
@@ -508,7 +511,7 @@ async fn model_quota_feedback_writes_model_scoped_cooldown_without_blocking_othe
         .await;
 
     let account = fixture.store.account(&selected).expect("selected account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
     let minimum_until = SystemTime::now() + Duration::from_secs(23 * 60 * 60);
     let scope = ProviderCooldownScope::upstream_model(failed_model);
     // model-scoped cooldown：目标模型被排除，账号级无 cooldown。
@@ -563,8 +566,8 @@ async fn model_access_feedback_reports_model_cooldown_without_blocking_the_accou
             .store
             .account(session.account_id())
             .expect("account")
-            .availability(),
-        AccountAvailability::Ready
+            .credential_state(),
+        CredentialState::Ready
     );
     assert!(matches!(
         fixture
@@ -594,7 +597,7 @@ async fn interrupted_stream_feedback_persists_the_grok2api_cooldown_state() {
         .store
         .account(session.account_id())
         .expect("account");
-    assert_eq!(account.availability(), AccountAvailability::Ready);
+    assert_eq!(account.credential_state(), CredentialState::Ready);
     assert!(
         fixture
             .cooldowns
@@ -630,8 +633,9 @@ async fn quota_feedback_uses_common_quota_exhausted_state() {
             .store
             .account(session.account_id())
             .expect("account")
-            .availability(),
-        AccountAvailability::QuotaExhausted
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted
     );
 }
 
@@ -673,13 +677,18 @@ async fn quota_feedback_should_follow_the_account_across_a_credential_rotation()
         .await;
 
     assert_eq!(
-        fixture.store.account(&id).expect("account").availability(),
-        AccountAvailability::QuotaExhausted
+        fixture
+            .store
+            .account(&id)
+            .expect("account")
+            .quota()
+            .access(),
+        QuotaAccessState::Exhausted
     );
 }
 
 #[tokio::test]
-async fn ordinary_success_should_not_clear_a_confirmed_quota_exhaustion() {
+async fn ordinary_success_clears_confirmed_exhaustion() {
     let fixture = SelectorFixture::new(&["quota-success"]).await;
     let session = fixture
         .selector
@@ -690,7 +699,6 @@ async fn ordinary_success_should_not_clear_a_confirmed_quota_exhaustion() {
         .selector
         .record_failure(&session, GrokCredentialFailure::FreeQuotaExhausted)
         .await;
-
     fixture.selector.record_success(&session).await;
 
     assert_eq!(
@@ -698,8 +706,9 @@ async fn ordinary_success_should_not_clear_a_confirmed_quota_exhaustion() {
             .store
             .account(session.account_id())
             .expect("account")
-            .availability(),
-        AccountAvailability::QuotaExhausted
+            .quota()
+            .access(),
+        QuotaAccessState::Allowed
     );
 }
 
@@ -1061,8 +1070,8 @@ async fn bare_402_cooldown_expires_and_account_recovers_without_persisted_exhaus
             .store
             .account(&selected)
             .expect("account")
-            .availability(),
-        AccountAvailability::Ready,
+            .credential_state(),
+        CredentialState::Ready,
         "bare 402 must not persist QuotaExhausted"
     );
     let next = fixture
diff --git a/backend/crates/providers/xai/tests/support.rs b/backend/crates/providers/xai/tests/support.rs
index f9dbe2f2e..9b2062cad 100644
--- a/backend/crates/providers/xai/tests/support.rs
+++ b/backend/crates/providers/xai/tests/support.rs
@@ -8,10 +8,10 @@ use std::time::{Duration, SystemTime};
 use async_trait::async_trait;
 use chrono::Utc;
 use gateway_core::engine::credential::{
-    AccountAvailability, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
-    CredentialRevision, LoadedCredential, NewProviderAccount, PlaintextCredential, ProviderAccount,
-    ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate, QuotaObservation,
-    QuotaWriteOutcome,
+    AccountErrorReason, AccountStateChange, CredentialCasOutcome, CredentialCasUpdate,
+    CredentialRevision, CredentialState, LoadedCredential, NewProviderAccount, PlaintextCredential,
+    ProviderAccount, ProviderAccountId, ProviderAccountStore, ProviderAccountUpdate,
+    QuotaAccessChange, QuotaObservation, QuotaState, QuotaWriteOutcome,
 };
 use gateway_core::error::{StoreError, StoreErrorKind};
 use gateway_core::provider_ports::{
@@ -23,11 +23,10 @@ use gateway_core::provider_ports::{
 use gateway_core::routing::ProviderKind;
 use provider_xai::{
     CreateGrokCredential, GROK_BILLING_URL, GrokAccountProfile, GrokBillingTransport,
-    GrokCatalogCacheError, GrokCatalogScope, GrokCredentialAdmin, GrokCredentialAvailability,
-    GrokCredentialCatalogCache, GrokCredentialCatalogService, GrokCredentialQuotaService,
-    GrokCredentialRepository, GrokCredentialRepositoryError, GrokEndpointPolicy,
-    GrokModelCatalogTransport, GrokOAuthSecret, GrokPlanCatalog, GrokReqwestTransportBuildError,
-    SecretValue, XaiConfig, XaiWireProfileState,
+    GrokCatalogCacheError, GrokCatalogScope, GrokCredentialAdmin, GrokCredentialCatalogCache,
+    GrokCredentialCatalogService, GrokCredentialQuotaService, GrokCredentialRepository,
+    GrokCredentialRepositoryError, GrokEndpointPolicy, GrokModelCatalogTransport, GrokOAuthSecret,
+    GrokPlanCatalog, GrokReqwestTransportBuildError, SecretValue, XaiConfig, XaiWireProfileState,
 };
 use reqwest::Client;
 use reqwest::redirect::Policy;
@@ -194,7 +193,6 @@ struct StoredAccount {
     account: ProviderAccount,
     credential: PlaintextCredential,
     quota: Option<QuotaObservation>,
-    last_error_message: Option<String>,
 }
 
 #[derive(Default)]
@@ -218,7 +216,7 @@ impl MemoryProviderAccountStore {
     pub fn last_error_message(&self, id: &ProviderAccountId) -> Option<String> {
         lock(&self.accounts)
             .get(id)
-            .and_then(|stored| stored.last_error_message.clone())
+            .and_then(|stored| stored.account.last_error_message().map(str::to_owned))
     }
 
     pub fn credential(&self, id: &ProviderAccountId) -> Option<PlaintextCredential> {
@@ -253,7 +251,6 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
                 account: account.account,
                 credential: account.credential,
                 quota: None,
-                last_error_message: None,
             },
         );
         Ok(())
@@ -335,7 +332,10 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
             AccountReplacement {
                 revision: next,
                 access_token_expires_at,
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 enabled: stored.account.enabled(),
                 has_refresh_token,
                 next_refresh_at,
@@ -372,7 +372,31 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
         if stored.account.revision() != observation.expected_revision {
             return Ok(QuotaWriteOutcome::Conflict);
         }
+        let quota = observation.state;
         stored.quota = Some(observation);
+        stored.account = rebuild_account(
+            &stored.account,
+            AccountReplacement::preserving(&stored.account).with_quota(quota),
+        );
+        Ok(QuotaWriteOutcome::Updated)
+    }
+
+    async fn apply_quota_access(
+        &self,
+        change: QuotaAccessChange,
+    ) -> Result<QuotaWriteOutcome, StoreError> {
+        let mut accounts = lock(&self.accounts);
+        let stored = accounts.get_mut(&change.account_id).ok_or_else(invalid)?;
+        if stored.account.revision() != change.expected_revision {
+            return Ok(QuotaWriteOutcome::Conflict);
+        }
+        stored.account = rebuild_account(
+            &stored.account,
+            AccountReplacement::preserving(&stored.account).with_quota(change.state),
+        );
+        if let Some(observation) = &mut stored.quota {
+            observation.state = change.state;
+        }
         Ok(QuotaWriteOutcome::Updated)
     }
 
@@ -387,7 +411,10 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
             AccountReplacement {
                 revision: stored.account.revision(),
                 access_token_expires_at: stored.account.access_token_expires_at(),
-                availability: change.availability,
+                credential_state: change.credential_state,
+                quota: stored.account.quota(),
+                last_error_reason: change.error_reason,
+                last_error_message: change.message.clone(),
                 enabled: stored.account.enabled(),
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -396,11 +423,6 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
                 plan_type: stored.account.plan_type().map(str::to_owned),
             },
         );
-        if change.availability == AccountAvailability::Ready {
-            stored.last_error_message = None;
-        } else if let Some(message) = change.message {
-            stored.last_error_message = Some(message);
-        }
         Ok(())
     }
 
@@ -412,7 +434,10 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
             AccountReplacement {
                 revision: stored.account.revision(),
                 access_token_expires_at: stored.account.access_token_expires_at(),
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 enabled: stored.account.enabled(),
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -436,7 +461,10 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
             AccountReplacement {
                 revision: stored.account.revision(),
                 access_token_expires_at: stored.account.access_token_expires_at(),
-                availability: stored.account.availability(),
+                credential_state: stored.account.credential_state(),
+                quota: stored.account.quota(),
+                last_error_reason: stored.account.last_error_reason(),
+                last_error_message: stored.account.last_error_message().map(str::to_owned),
                 enabled,
                 has_refresh_token: stored.account.has_refresh_token(),
                 next_refresh_at: stored.account.next_refresh_at(),
@@ -457,7 +485,10 @@ impl ProviderAccountStore for MemoryProviderAccountStore {
 struct AccountReplacement {
     revision: CredentialRevision,
     access_token_expires_at: Option<SystemTime>,
-    availability: AccountAvailability,
+    credential_state: CredentialState,
+    quota: QuotaState,
+    last_error_reason: Option<AccountErrorReason>,
+    last_error_message: Option<String>,
     enabled: bool,
     has_refresh_token: bool,
     next_refresh_at: Option<SystemTime>,
@@ -466,6 +497,30 @@ struct AccountReplacement {
     plan_type: Option<String>,
 }
 
+impl AccountReplacement {
+    fn preserving(account: &ProviderAccount) -> Self {
+        Self {
+            revision: account.revision(),
+            access_token_expires_at: account.access_token_expires_at(),
+            credential_state: account.credential_state(),
+            quota: account.quota(),
+            last_error_reason: account.last_error_reason(),
+            last_error_message: account.last_error_message().map(str::to_owned),
+            enabled: account.enabled(),
+            has_refresh_token: account.has_refresh_token(),
+            next_refresh_at: account.next_refresh_at(),
+            name: account.name().to_owned(),
+            email: account.email().map(str::to_owned),
+            plan_type: account.plan_type().map(str::to_owned),
+        }
+    }
+
+    fn with_quota(mut self, quota: QuotaState) -> Self {
+        self.quota = quota;
+        self
+    }
+}
+
 fn rebuild_account(previous: &ProviderAccount, replacement: AccountReplacement) -> ProviderAccount {
     ProviderAccount::new(
         previous.id().clone(),
@@ -481,7 +536,13 @@ fn rebuild_account(previous: &ProviderAccount, replacement: AccountReplacement)
         previous.upstream_account_id().map(str::to_owned),
         replacement.plan_type,
     )
-    .with_runtime_state(replacement.enabled, replacement.availability)
+    .with_account_facts(
+        replacement.enabled,
+        replacement.credential_state,
+        replacement.quota,
+        replacement.last_error_reason,
+        replacement.last_error_message,
+    )
     .with_refresh_schedule(replacement.has_refresh_token, replacement.next_refresh_at)
 }
 
@@ -549,8 +610,9 @@ pub fn create_input(suffix: &str, subject: &str) -> CreateGrokCredential {
         },
         account: profile(subject),
         enabled: true,
-        initial_availability: GrokCredentialAvailability::Unknown,
-        initial_availability_reason: None,
+        initial_credential_state: CredentialState::Unknown,
+        initial_error_reason: None,
+        initial_error_message: None,
     }
 }
 
diff --git a/backend/migrations/.frozen-sha256 b/backend/migrations/.frozen-sha256
index ce10cb924..bdcefc8ac 100644
--- a/backend/migrations/.frozen-sha256
+++ b/backend/migrations/.frozen-sha256
@@ -1,3 +1,4 @@
 5f79e74c9a7a7366c39cd1afe43175eff6c44afe9217c0f26f33f173bd40c781  0001_initial.sql
 f4168f7e23d42cf9d37096339e931b0e0c823f7a8dbfc6580a04f096c4c3d8e3  0002_provider_accounts_nullable_upstream_user_id.sql
 4163f61183d9e90f1368c08f614040d6a1a0048de3886a77dd708ce21430b2d0  0003_backfill_openai_access_token_expiry.sql
+b41bb3be5a84b95852158d82267456f8415811a1137025581eefd1c96c0882d1  0004_normalize_account_state_facts.sql
diff --git a/backend/migrations/0004_normalize_account_state_facts.sql b/backend/migrations/0004_normalize_account_state_facts.sql
new file mode 100644
index 000000000..8b511e6ab
--- /dev/null
+++ b/backend/migrations/0004_normalize_account_state_facts.sql
@@ -0,0 +1,165 @@
+-- Separate credential identity facts from quota access facts. The public account
+-- status remains derived at read time because Redis cooldowns and reset times are
+-- time-dependent.
+
+alter table provider_accounts
+  rename column availability to credential_state;
+
+alter table provider_accounts
+  rename column availability_observed_at to credential_observed_at;
+
+alter table provider_accounts
+  drop constraint provider_accounts_availability_ck;
+
+alter table provider_accounts
+  add constraint provider_accounts_credential_state_ck check (
+    credential_state in ('unknown', 'ready', 'expired', 'banned', 'invalid')
+  ) not valid;
+
+alter table provider_accounts
+  add column quota_access_state text not null default 'unknown',
+  add column quota_evidence text,
+  add column quota_access_observed_at timestamptz,
+  add column quota_reset_at timestamptz,
+  add column last_error_reason text;
+
+alter table provider_accounts
+  drop constraint provider_accounts_quota_observation_ck;
+
+-- Old quota_exhausted credential states are quota facts. Re-derive OpenAI quota
+-- access from the raw authoritative response and never trust the old percentage-
+-- derived quota_limit_reached boolean.
+update provider_accounts
+set
+  quota_access_state = case
+    when provider_kind = 'openai'
+      and provider_quota_json #>> '{rate_limit,allowed}' = 'true'
+      then 'allowed'
+    when provider_kind = 'openai'
+      and (
+        provider_quota_json #>> '{rate_limit,allowed}' = 'false'
+        or (
+          coalesce(provider_quota_json #>> '{rate_limit,allowed}', '') <> 'true'
+          and (
+            provider_quota_json #>> '{rate_limit,limit_reached}' = 'true'
+            or provider_quota_json #>> '{rate_limit,primary_window,limit_reached}' = 'true'
+          )
+        )
+      )
+      then 'exhausted'
+    when provider_kind = 'xai' and credential_state = 'quota_exhausted'
+      then 'exhausted'
+    when provider_quota_json is not null then 'unknown'
+    else 'unknown'
+  end,
+  quota_evidence = case
+    when provider_kind = 'openai'
+      and provider_quota_json #>> '{rate_limit,allowed}' = 'false'
+      then 'provider_denied'
+    when provider_kind = 'openai'
+      and coalesce(provider_quota_json #>> '{rate_limit,allowed}', '') <> 'true'
+      and (
+        provider_quota_json #>> '{rate_limit,limit_reached}' = 'true'
+        or provider_quota_json #>> '{rate_limit,primary_window,limit_reached}' = 'true'
+      )
+      then 'account_limit_reached'
+    when provider_kind = 'xai' and credential_state = 'quota_exhausted'
+      then 'usage_limit_reached'
+    else null
+  end,
+  quota_access_observed_at = case
+    when provider_kind = 'openai' and provider_quota_json is not null
+      then quota_observed_at
+    when provider_kind = 'xai' and credential_state = 'quota_exhausted'
+      then credential_observed_at
+    else null
+  end,
+  quota_reset_at = case
+    when provider_kind = 'openai'
+      and jsonb_typeof(provider_quota_json #> '{rate_limit,primary_window,reset_at}') = 'number'
+      then to_timestamp((provider_quota_json #>> '{rate_limit,primary_window,reset_at}')::double precision)
+    else null
+  end,
+  credential_state = case
+    when credential_state = 'quota_exhausted' and upstream_user_id is not null then 'ready'
+    when credential_state = 'quota_exhausted' then 'unknown'
+    else credential_state
+  end,
+  last_error_reason = case credential_state
+    when 'unknown' then 'account_unverified'
+    when 'expired' then 'credential_expired'
+    when 'invalid' then 'credential_invalid'
+    when 'banned' then 'account_banned'
+    else null
+  end,
+  last_error_message = case
+    when credential_state in ('unknown', 'expired', 'invalid', 'banned') then last_error_message
+    else null
+  end;
+
+alter table provider_accounts
+  validate constraint provider_accounts_credential_state_ck;
+
+alter table provider_accounts
+  add constraint provider_accounts_quota_access_state_ck check (
+    quota_access_state in ('unknown', 'allowed', 'exhausted')
+  ),
+  add constraint provider_accounts_quota_evidence_ck check (
+    quota_evidence is null
+    or quota_evidence in (
+      'provider_denied',
+      'account_limit_reached',
+      'usage_limit_reached',
+      'payment_required'
+    )
+  ),
+  add constraint provider_accounts_quota_fact_ck check (
+    (quota_access_state = 'unknown' and quota_evidence is null and quota_reset_at is null)
+    or (
+      quota_access_state = 'allowed'
+      and quota_evidence is null
+      and quota_access_observed_at is not null
+      and quota_reset_at is null
+    )
+    or (
+      quota_access_state = 'exhausted'
+      and quota_evidence is not null
+      and quota_access_observed_at is not null
+    )
+  ),
+  add constraint provider_accounts_quota_observation_ck check (
+    (provider_quota_json is null) = (quota_observed_at is null)
+  ),
+  add constraint provider_accounts_error_reason_ck check (
+    last_error_reason is null
+    or last_error_reason in (
+      'account_unverified',
+      'access_token_expired',
+      'credential_expired',
+      'credential_invalid',
+      'account_banned'
+    )
+  );
+
+drop index provider_accounts_availability_idx;
+create index provider_accounts_credential_state_idx
+  on provider_accounts (credential_state, id);
+create index provider_accounts_quota_access_idx
+  on provider_accounts (quota_access_state, quota_reset_at, id);
+
+alter table provider_accounts
+  drop column quota_limit_reached;
+
+alter table provider_accounts
+  rename constraint provider_accounts_time_ck to provider_accounts_time_ck_old;
+
+alter table provider_accounts
+  drop constraint provider_accounts_time_ck_old;
+
+alter table provider_accounts
+  add constraint provider_accounts_time_ck check (
+    created_at <= updated_at
+    and credential_observed_at <= updated_at
+    and (quota_access_observed_at is null or quota_access_observed_at <= updated_at)
+    and (quota_observed_at is null or quota_observed_at <= updated_at)
+  );
diff --git a/docs/api.md b/docs/api.md
index 3e7870a7b..013f042b2 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -112,7 +112,7 @@ OpenAI 路径保留客户端 Responses wire 语义：请求 body 的未知字段
 账号列表支持以下稳定值：
 
 - `provider`: `all`、`openai`、`xai`；
-- `status`: `active`、`expired`、`quota_exhausted`、`disabled`、`banned`；
+- `status`: `normal`、`quota_exhausted`、`rate_limited`、`disabled`、`error`；
 - `sortBy`: `email`、`status`、`planType`、`usage`、`lastUsedAt`、`expiresAt`；
 - `sortDirection`: `asc`、`desc`。
 
@@ -184,13 +184,19 @@ OAuth start 使用：
   但上游 authorization code 本身通常只能交换一次；已完成过 token exchange 时应重新创建 OAuth flow。
 - `GET /accounts/quota` 只读取最后一次落库快照；`POST /accounts/quota/refresh` 才访问上游。access token
   已过期时，额度刷新要求先走 credential 刷新或重新授权，不会拿过期 token 探测额度。
-- 成功额度观测会 revision-fenced 写入 quota，并在 `active` 与 `quota_exhausted` 等额度所属状态间同步；
-  不会清除 `expired`、`banned` 等 credential/封禁终态。额度接口的 401/403 也不足以判定 refresh token
-  永久失效，credential 终态只由 OAuth refresh 的明确永久错误写入。
+- 成功额度观测会 revision-fenced 写入 quota；明确 `Allowed` 投影为 `normal`，明确耗尽投影为
+  `quota_exhausted`。额度观测不会清除凭据过期、无效或封禁事实；这些事实统一投影为 `error`，并由
+  `errorReason` 区分。额度接口的 401/403 也不足以判定 refresh token 永久失效，credential 终态只由
+  OAuth refresh 的明确永久错误写入。
 - 正常 Responses 请求会解析上游响应的 rate-limit headers，合并进同一 quota 快照并同步状态。Free、
   K12 等套餐共用该状态机；套餐只参与账号展示和按套餐隔离的模型目录 cache，不存在 K12 专属额度路径。
-- 账号页没有定时静默轮询。手工额度刷新完成后页面会重新读取该账号；请求驱动或后台任务产生的状态
-  变化，需要下一次显式查询账号列表后才会显示。
+- 账号展开区的 Token 结构和模型排行使用代表性账号级额度窗口聚合，查询边界严格为
+  `[resetAt - windowSeconds, resetAt)`；额度刷新若返回了更早的重置时间，会按新边界重新聚合。无法取得
+  完整窗口边界或只有模型专属额度时显示无数据，不回退成历史累计。金额原值保持完整精度，USD 展示值
+  小于 1 美元时最多保留四位小数，其余保留两位。
+- 账号页没有定时静默轮询。手工额度刷新只替换响应中的账号行并同步状态汇总，不触发整页 loading；若
+  新状态不符合当前筛选，该行从当前页移除。请求驱动或后台任务产生的状态变化，需要下一次显式查询账号
+  列表后才会显示。
 
 ## 6. Client Key
 
diff --git a/docs/architecture.md b/docs/architecture.md
index db4b9301e..8ef75f0eb 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -116,7 +116,17 @@ Provider 独占以下职责：
 - OpenAI 是逐字节透明代理：请求 body 的未知字段和字段顺序保持不变（受控模型映射除外），上游 wire 是客户端可见的事实来源，HTTP SSE 帧以原始字节原样下发，WebSocket 上游 JSON 文本原样下发；response ID 以 opaque bytes 存储，不假设 UUID 或固定长度。canonical facts 只从同一帧旁路解析，用于观测、亲和与计费。仅网关内部帧（rate limits、metadata）被就地消费，不向客户端转发。
 - xAI 是翻译层：把 Grok wire 解码后重新合成 Responses wire 事件，不承诺字节透明；上游错误按结构化 message/code/type 透出，message 中的 UUID 账号指纹替换为占位符。
 
-credential 更新使用 `credential_revision` CAS。认证永久失败、封禁、额度耗尽和带截止时间的 cooldown 是账号运行时事实。cooldown 到期后，Core 的有效调度谓词会自然允许账号重新参与选择；Redis cooldown 只是热缓存。成功调用或成功额度观测才可把账号状态重新观测为 `ready`。推理请求的账号/model cooldown 只约束数据面调度，不参与 OAuth refresh；OpenAI 与 xAI 的 OAuth refresh 请求状态不明确时只按 OAuth 自身的有界退避推进该 credential 的 `next_refresh_at`：前五次约为 5/15/45/135/300 秒，之后约每 10 分钟恢复；仍有效 AT 时不晚于其到期时刻，AT 到期后仍按该节奏恢复，至 `AT 到期 + 24h` 才终态化。自动 refresh 的瞬态失败（限流、5xx、超时、畸形响应）保留现有凭据并按指数退避推迟下一次刷新，不把账号标记为失效；上游明确的永久错误（`invalid_grant`、封禁）仍立即写入终态失效。
+credential 更新使用 `credential_revision` CAS。PostgreSQL 分别保存凭据事实与额度访问事实；带截止时间的
+429 cooldown 只保存在 Redis，是唯一的临时冷却运行时事实，不进入 Provider quota 展示模型。Store 把三类
+事实交给 Core 的唯一解析器，投影为 `normal`、`quota_exhausted`、`rate_limited`、`disabled` 或 `error`；
+投影为 `rate_limited` 时同时携带有效的 `rate_limited_until`，到期重算后该时间和状态一起消失。若没有其它
+阻塞事实，账号才恢复为 `normal`。成功推理或明确的成功额度观测可以写入 `Allowed`；本地时钟与不确定响应
+不能伪造恢复。推理请求的账号/model cooldown 只约束数据面调度，不参与 OAuth refresh；OpenAI 与 xAI 的
+OAuth refresh 请求状态不明确时只按 OAuth 自身的有界退避推进该 credential 的 `next_refresh_at`：前五次
+约为 5/15/45/135/300 秒，之后约每 10 分钟恢复；仍有效 Access Token 时不晚于其到期时刻，Access Token
+到期后仍按该节奏恢复，至“到期 + 24 小时”才终态化。自动 refresh 的瞬态失败（限流、5xx、超时、畸形
+响应）保留现有凭据并按指数退避推迟下一次刷新，不把账号标记为失效；上游明确的永久错误
+（`invalid_grant`、封禁）仍立即写入终态失效。
 
 `refresh_token_expires_at` 不是公共 SQL 列或 Core 权威状态。xAI 可在 `provider_credentials_json` 内保存它作为 Provider 私有提示；真正失效以 refresh endpoint 返回的永久错误为准。
 
@@ -127,12 +137,15 @@ exchange 成功后执行同一补全。两条路径不执行 JWKS 验签，不
 credential revision；complete 阶段重新读取目标账号及其当前 revision，并以当前 revision 做最终 CAS。
 重新授权和手工或后台 RT refresh 只轮换目标账号的 token，保留既有账号资料与 OAuth principal。
 
-credential 与 quota 是两套状态机。主动 quota refresh 会拒绝过期 access token；quota 探测的
-401/403 不具备判定 refresh token 永久失效的证据。成功主动观测和正常推理响应中的 rate-limit header
-观测都 revision-fenced 写入同一 quota，并转换 readiness、`QuotaExhausted` 或 `Cooldown` 等额度事实；
-只有明确的 deactivated workspace 才能由额度链路写入 `Banned`，且额度观测不能清除 `Invalid`、
-`Expired`、`Banned`。Free、K12 等套餐复用该逻辑；`plan_type` 在此不参与额度分支，只作为 Provider
-事实并用于隔离不同套餐的 catalog cache。
+credential 与 quota 是两组独立事实，不是两套对外状态。主动 quota refresh 会拒绝过期 Access Token；
+quota 探测的 401/403 不具备判定 Refresh Token 永久失效的证据。成功主动观测和正常推理响应中的
+rate-limit header 观测都 revision-fenced 写入同一 quota；只有明确的访问证据才写 `Allowed` 或
+`Exhausted`。只有明确的 deactivated workspace 才能由额度链路写入 `Banned` 凭据事实，且额度观测不能
+清除 `Invalid`、`Expired`、`Banned`。这些凭据事实对外统一投影为 `error` 并携带稳定原因。Free、K12 等
+套餐复用该逻辑；`plan_type` 在此不参与额度分支，只作为 Provider 事实并用于隔离不同套餐的 catalog cache。
+账号展开用量不读取 retention 范围累计值，而是选择带完整边界且可归属到账号的代表性额度窗口，并按
+`[reset_at - window_seconds, reset_at)` 聚合请求、Token、模型和成本；额度重置边界变化后，同一查询随刷新
+结果重算。模型专属窗口不会错误复用账号总用量，边界不完整时也不伪造“当前窗口”统计。
 
 ## 7. 控制面与内部 revision
 
@@ -156,7 +169,7 @@ Admin API 不要求客户端提交配置 revision，也不向客户端暴露配
 | `admin_audit_events` | 管理 mutation 审计 |
 | `client_api_keys` | 客户端鉴权、限额与授权范围 |
 | `runtime_settings` | 全局配置与 `config_revision` |
-| `provider_accounts` | 账号资料、Provider-owned 明文 credential JSON、revision、quota、cooldown |
+| `provider_accounts` | 账号资料、Provider-owned 明文 credential JSON、revision、凭据事实与规范化 quota 事实 |
 | `model_requests` | 请求、attempt、计费、交付与恢复事实 |
 | `ops_events` | 脱敏运行事件 |
 | `backup_settings` | S3/R2 存储、Cron 计划与保留策略单例配置 |
@@ -184,13 +197,14 @@ heartbeat；计划时间点冲突只记录日志/指标并推进游标，不产
 
 业务 schema 由 `backend/migrations/0001_initial.sql` 直接定义当前大版本的完整新库基线，其中
 response ID 使用无格式假设的 UTF-8 bytes，`model_requests.service_tier` 保存响应观测到的服务档位，
-且额度耗尽账号可以携带冷却截止时间。同一大版本内已合入的迁移永久冻结——
+账号对外五态由 PostgreSQL 凭据/额度事实与 Redis 429 冷却通过 Core 唯一解析器动态派生，
+不保存重复的 `status` 列。同一大版本内已合入的迁移永久冻结——
 `.frozen-sha256` 是冻结清单，CI 校验清单相对 PR base 只增不改，启动时 sqlx 重校验已应用
 迁移的 checksum，不一致直接拒绝启动。规则见 `backend/migrations/README.md`。
 
 ## 9. Redis 终态
 
-Redis 保存的协调状态恰好是：客户端 admission 热状态、credential lease/fencing 与调度信号、账号 cooldown 与 availability 热缓存、catalog 缓存、Provider circuit、会话亲和与会话级账号排除、continuation pin、OAuth pending flow、worker leader lease 以及 runtime change 通知。Redis 丢失后必须从 PostgreSQL 或 Provider 事实恢复；恢复完成前需要保护的 acquire 路径 fail closed。
+Redis 保存的协调状态恰好是：客户端 admission 热状态、credential lease/fencing 与调度信号、账号 429 cooldown 与 credential state 可重建缓存、catalog 缓存、Provider circuit、会话亲和与会话级账号排除、continuation pin、OAuth pending flow、worker leader lease以及 runtime change 通知。Redis 丢失后必须从 PostgreSQL 或 Provider 事实恢复；恢复完成前需要保护的 acquire 路径 fail closed。
 
 多副本部署时，跨副本协调面只有上述 Redis 状态与 PostgreSQL 事实；WebSocket 连接池、请求画像与 RuntimeSnapshot 副本都是进程内状态，其中 RuntimeSnapshot 依靠周期对账收敛，请求画像依靠各自的官方版本检查收敛。
 
diff --git a/frontend/src/api/modules/accounts.ts b/frontend/src/api/modules/accounts.ts
index a9e7fe678..ed4004a20 100644
--- a/frontend/src/api/modules/accounts.ts
+++ b/frontend/src/api/modules/accounts.ts
@@ -1,5 +1,15 @@
 import request from '../request'
 
+export type AccountStatus
+  = 'normal' | 'quota_exhausted' | 'rate_limited' | 'disabled' | 'error'
+
+export type AccountErrorReason
+  = 'account_unverified'
+    | 'access_token_expired'
+    | 'credential_expired'
+    | 'credential_invalid'
+    | 'account_banned'
+
 export interface AccountQuotaWindow {
   key: string
   group: string
@@ -104,11 +114,9 @@ export interface Account {
   planType: string | null
   authenticationKind: string
   hasRefreshToken: boolean
-  status: string
-  displayStatus: string
-  errorReason: string | null
+  status: AccountStatus
+  errorReason: AccountErrorReason | null
   errorMessage: string | null
-  availability: string
   enabled: boolean
   accessTokenExpiresAt: string | null
   accessTokenExpiresAtDisplay: string | null
diff --git a/frontend/src/api/modules/dashboard.ts b/frontend/src/api/modules/dashboard.ts
index a900193bc..dc60e077b 100644
--- a/frontend/src/api/modules/dashboard.ts
+++ b/frontend/src/api/modules/dashboard.ts
@@ -143,14 +143,11 @@ export interface DashboardAccountUsage {
 
 export interface DashboardPoolSummary {
   total: number
-  active: number
-  rateLimited: number
-  expired: number
-  invalid: number
+  normal: number
   quotaExhausted: number
-  refreshing: number | null
+  rateLimited: number
   disabled: number
-  banned: number
+  error: number
 }
 
 export interface DashboardCapacityInfo {
diff --git a/frontend/src/views/accounts/components/AccountStatusBadge.vue b/frontend/src/views/accounts/components/AccountStatusBadge.vue
index 30d39342a..820fbe053 100644
--- a/frontend/src/views/accounts/components/AccountStatusBadge.vue
+++ b/frontend/src/views/accounts/components/AccountStatusBadge.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import type { AccountErrorReason, AccountStatus } from '@/api'
 import { AlertTriangle, CircleCheck, Gauge, Power, Timer } from '@lucide/vue'
 import { computed } from 'vue'
 
@@ -8,8 +9,8 @@ import { errorReasonLabels, statusLabels, statusTones } from '../constants'
 
 const props = withDefaults(
   defineProps<{
-    status: string
-    errorReason?: string | null
+    status: AccountStatus
+    errorReason?: AccountErrorReason | null
     errorMessage?: string | null
     rateLimitedUntil?: string | null
     variant?: 'inline' | 'pill'
@@ -55,12 +56,12 @@ const statusStyles = {
   },
 } as const
 
-const tone = computed(() => statusTones[props.status] || 'normal')
+const tone = computed(() => statusTones[props.status])
 const statusStyle = computed(() => statusStyles[tone.value])
-const label = computed(() => statusLabels[props.status] || props.status)
+const label = computed(() => statusLabels[props.status])
 const reasonLabel = computed(() =>
   props.errorReason
-    ? errorReasonLabels[props.errorReason] || props.errorReason
+    ? errorReasonLabels[props.errorReason]
     : null,
 )
 const errorText = computed(() => props.errorMessage || null)
@@ -102,16 +103,16 @@ const recoveryHint = computed(() => {
     return '冷却结束后，系统会自动恢复调度。'
 
   switch (props.errorReason) {
-    case 'expired':
-    case 'token_expired':
+    case 'account_unverified':
+    case 'access_token_expired':
+    case 'credential_expired':
       return '重新授权后，账号会重新参与调度。'
-    case 'invalid':
+    case 'credential_invalid':
       return '请更新或重新导入凭据，再次测试连接。'
-    case 'banned':
+    case 'account_banned':
       return '请确认上游账号状态，解除限制后再启用。'
-    default:
-      return '重新测试连接以获取最新状态。'
   }
+  return '重新测试连接以获取最新状态。'
 })
 
 const triggerLabel = computed(() =>
diff --git a/frontend/src/views/accounts/components/AccountUsagePanel.vue b/frontend/src/views/accounts/components/AccountUsagePanel.vue
index 36a9a0cea..9af819678 100644
--- a/frontend/src/views/accounts/components/AccountUsagePanel.vue
+++ b/frontend/src/views/accounts/components/AccountUsagePanel.vue
@@ -11,9 +11,12 @@ defineProps<{
     class="grid gap-4 rounded-lg bg-(--cp-bg-surface) p-4 shadow-(--cp-shadow-control) xl:grid-cols-[0.52fr_1.48fr]"
   >
     <div>
-      <h3 class="m-0 mb-3 text-[14px] font-heavy text-(--cp-text-primary)">
-        Token 结构
-      </h3>
+      <div class="mb-3 flex items-baseline justify-between gap-3">
+        <h3 class="m-0 text-[14px] font-heavy text-(--cp-text-primary)">
+          Token 结构
+        </h3>
+        <span class="text-[11px] font-emphasis text-(--cp-text-muted)">当前额度窗口</span>
+      </div>
       <div class="grid gap-2">
         <div class="flex items-center justify-between rounded-lg bg-(--cp-success-bg) px-3 py-2">
           <span class="text-[12px] font-bold text-(--cp-success-text)">输入 Tokens</span>
@@ -55,10 +58,11 @@ defineProps<{
         <h3 class="m-0 text-[14px] font-heavy text-(--cp-text-primary)">
           模型使用排行
         </h3>
+        <span class="text-[11px] font-emphasis text-(--cp-text-muted)">当前额度窗口</span>
       </div>
 
       <div
-        class="grid grid-cols-[1.2fr_0.7fr_0.8fr_1fr_1fr_1fr_1fr_1fr_1.4fr] gap-3 pb-2 text-[11px] font-heavy text-(--cp-text-secondary) shadow-[inset_0_-1px_0_var(--cp-divider-subtle)]"
+        class="grid grid-cols-[1.5fr_0.7fr_0.8fr_1fr_1fr_1fr_1fr_1fr_1.4fr] gap-3 pb-2 text-[11px] font-heavy text-(--cp-text-secondary) shadow-[inset_0_-1px_0_var(--cp-divider-subtle)]"
       >
         <span>模型</span>
         <span>调用</span>
@@ -66,9 +70,9 @@ defineProps<{
         <span>输入</span>
         <span>输出</span>
         <span>缓存</span>
-        <span>总TOKEN</span>
-        <span>计费金额</span>
-        <span>最近请求时间</span>
+        <span>总计</span>
+        <span>计费</span>
+        <span>最近请求</span>
       </div>
       <div
         v-if="account.usage.models.length === 0"
@@ -80,7 +84,7 @@ defineProps<{
         <div
           v-for="model in account.usage.models"
           :key="model.model"
-          class="grid grid-cols-[1.2fr_0.7fr_0.8fr_1fr_1fr_1fr_1fr_1fr_1.4fr] gap-3 pt-3 text-[12px] font-emphasis text-(--cp-text-primary)"
+          class="grid grid-cols-[1.5fr_0.7fr_0.8fr_1fr_1fr_1fr_1fr_1fr_1.4fr] gap-3 pt-3 text-[12px] font-emphasis text-(--cp-text-primary)"
         >
           <span class="truncate">{{ model.model }}</span>
           <span>{{ model.requestCountDisplay }}</span>
diff --git a/frontend/src/views/accounts/composables/useAccountConnectionTest.ts b/frontend/src/views/accounts/composables/useAccountConnectionTest.ts
index 501b9738c..bd256e4c2 100644
--- a/frontend/src/views/accounts/composables/useAccountConnectionTest.ts
+++ b/frontend/src/views/accounts/composables/useAccountConnectionTest.ts
@@ -42,16 +42,11 @@ interface ConnectionTestEvent {
   model?: string
   payload?: ConnectionTestRequestPayload
   success?: boolean
-  accountStatus?: string
   upstreamBody?: string
   upstreamStatus?: number
   error?: string
 }
 
-interface AccountConnectionTestOptions {
-  onAccountStatus: (accountId: string, status: string) => void
-}
-
 function connectionTestErrorText(event: ConnectionTestEvent) {
   if (typeof event.upstreamBody === 'string' && event.upstreamBody.length > 0)
     return event.upstreamBody
@@ -69,7 +64,7 @@ function connectionTestFailureLabel(event: ConnectionTestEvent) {
     : '未能向上游发起请求'
 }
 
-export function useAccountConnectionTest(options: AccountConnectionTestOptions) {
+export function useAccountConnectionTest(options: { reload: () => Promise<unknown> }) {
   const showConnectionTestModal = shallowRef(false)
   const testingAccount = shallowRef<Account | null>(null)
   const connectionTestStatus = shallowRef<ConnectionTestStatus>('idle')
@@ -232,18 +227,6 @@ export function useAccountConnectionTest(options: AccountConnectionTestOptions)
     )
   }
 
-  function applyAccountStatus(status?: string) {
-    const account = testingAccount.value
-    if (!account || !status)
-      return
-    testingAccount.value = {
-      ...account,
-      status,
-      displayStatus: status,
-    }
-    options.onAccountStatus(account.id, status)
-  }
-
   function clearConnectionTestRun() {
     const run = connectionTestRun
     connectionTestRun = undefined
@@ -283,7 +266,6 @@ export function useAccountConnectionTest(options: AccountConnectionTestOptions)
       return
     }
     if (event.type === 'test_complete') {
-      applyAccountStatus(event.accountStatus)
       if (event.success) {
         if (!connectionTestContent.value) {
           setConnectionTestLog('response', '响应完成', 'success', '上游已完成，没有返回文本内容')
@@ -297,10 +279,10 @@ export function useAccountConnectionTest(options: AccountConnectionTestOptions)
         finishConnectionTest('error')
       }
       clearConnectionTestRun()
+      void options.reload()
       return
     }
     if (event.type === 'error') {
-      applyAccountStatus(event.accountStatus)
       connectionTestError.value = connectionTestErrorText(event)
       appendConnectionTestLog(
         connectionTestFailureLabel(event),
@@ -309,6 +291,7 @@ export function useAccountConnectionTest(options: AccountConnectionTestOptions)
       )
       finishConnectionTest('error')
       clearConnectionTestRun()
+      void options.reload()
     }
   }
 
diff --git a/frontend/src/views/accounts/composables/useAccountMutations.ts b/frontend/src/views/accounts/composables/useAccountMutations.ts
index db124eb75..00f4b3ac1 100644
--- a/frontend/src/views/accounts/composables/useAccountMutations.ts
+++ b/frontend/src/views/accounts/composables/useAccountMutations.ts
@@ -1,7 +1,5 @@
 import type { Ref } from 'vue'
 import type { getAccounts } from '@/api'
-import type { BaseTableSort } from '@/components/base/BaseTable/columns'
-
 import dayjs from 'dayjs'
 import { ref, watch } from 'vue'
 import {
@@ -9,7 +7,6 @@ import {
   disableAccount,
   enableAccount,
   exportAccounts,
-  getAccountQuota,
   refreshAccount,
   refreshAccountQuota,
 } from '@/api'
@@ -23,22 +20,11 @@ import { useAccountOnboarding } from './useAccountOnboarding'
 
 type AccountRow = Awaited<ReturnType<typeof getAccounts>>['items'][number]
 
-const accountStatusSortRank: Record<string, number> = {
-  normal: 0,
-  quota_exhausted: 1,
-  rate_limited: 2,
-  disabled: 3,
-  error: 4,
-}
-
 export function useAccountMutations(options: {
   accounts: Ref<AccountRow[]>
-  accountSummary: Ref<Awaited<ReturnType<typeof getAccounts>>['summary']>
-  statusQuery: Ref<string>
-  sort: Ref<BaseTableSort | undefined>
   selectedIds: Ref<Set<string>>
-  totalAccounts: Ref<number>
   reload: () => Promise<unknown>
+  replaceAccount: (account: AccountRow) => boolean
 }) {
   const loadAccounts = options.reload
   const { downloadJson } = useDownload()
@@ -188,13 +174,13 @@ export function useAccountMutations(options: {
   async function handleRefreshQuota(accountId: string) {
     await refreshingQuotaAccounts.run(accountId, async () => {
       try {
-        await withMinimumDuration(async () => {
-          await refreshAccountQuota({ accountId })
-          const result = await getAccountQuota({ accountId })
-          options.accounts.value = options.accounts.value.map(account =>
-            account.id === accountId ? { ...account, ...result.account } : account,
-          )
-        })
+        const result = await withMinimumDuration(() => refreshAccountQuota({ accountId }))
+        const remainsVisible = options.replaceAccount(result.account)
+        if (!remainsVisible) {
+          const selectedIds = new Set(options.selectedIds.value)
+          selectedIds.delete(accountId)
+          options.selectedIds.value = selectedIds
+        }
         toast.success('额度已刷新')
       }
       catch (error: unknown) {
@@ -203,81 +189,6 @@ export function useAccountMutations(options: {
     })
   }
 
-  function patchAccountStatus(accountId: string, status: string) {
-    const current = options.accounts.value.find(account => account.id === accountId)
-    if (!current)
-      return
-
-    if (options.statusQuery.value && options.statusQuery.value !== status) {
-      options.accounts.value = options.accounts.value.filter(account => account.id !== accountId)
-      options.totalAccounts.value = Math.max(0, options.totalAccounts.value - 1)
-      options.selectedIds.value = new Set(
-        [...options.selectedIds.value].filter(id => id !== accountId),
-      )
-    }
-    else {
-      const rows = options.accounts.value.map(account =>
-        account.id === accountId
-          ? {
-              ...account,
-              status,
-              displayStatus: status,
-            }
-          : account,
-      )
-      options.accounts.value = sortAccountsByStatus(rows)
-    }
-
-    if (current.status === status)
-      return
-    options.accountSummary.value = {
-      ...options.accountSummary.value,
-      normal: Math.max(
-        0,
-        options.accountSummary.value.normal
-        + Number(status === 'normal')
-        - Number(current.status === 'normal'),
-      ),
-      quotaExhausted: Math.max(
-        0,
-        options.accountSummary.value.quotaExhausted
-        + Number(status === 'quota_exhausted')
-        - Number(current.status === 'quota_exhausted'),
-      ),
-      rateLimited: Math.max(
-        0,
-        options.accountSummary.value.rateLimited
-        + Number(status === 'rate_limited')
-        - Number(current.status === 'rate_limited'),
-      ),
-      disabled: Math.max(
-        0,
-        options.accountSummary.value.disabled
-        + Number(status === 'disabled')
-        - Number(current.status === 'disabled'),
-      ),
-      error: Math.max(
-        0,
-        options.accountSummary.value.error
-        + Number(status === 'error')
-        - Number(current.status === 'error'),
-      ),
-    }
-  }
-
-  function sortAccountsByStatus(rows: AccountRow[]) {
-    if (options.sort.value?.key !== 'status')
-      return rows
-    const direction = options.sort.value.direction === 'asc' ? 1 : -1
-    return [...rows].sort((left, right) => {
-      const rankDifference
-        = (accountStatusSortRank[left.status] ?? 7) - (accountStatusSortRank[right.status] ?? 7)
-      return rankDifference === 0
-        ? left.id.localeCompare(right.id) * direction
-        : rankDifference * direction
-    })
-  }
-
   async function handleToggleSchedule(account: AccountRow) {
     const action = account.enabled ? 'disable' : 'enable'
     await updatingStatusAccounts.run(account.id, async () => {
@@ -362,7 +273,6 @@ export function useAccountMutations(options: {
     handleExportAccounts,
     handleRefresh,
     handleRefreshQuota,
-    patchAccountStatus,
     handleToggleSchedule,
     scheduleActionLabel,
   }
diff --git a/frontend/src/views/accounts/composables/useAccountsQuery.ts b/frontend/src/views/accounts/composables/useAccountsQuery.ts
index 7c94e63db..a6dd8727a 100644
--- a/frontend/src/views/accounts/composables/useAccountsQuery.ts
+++ b/frontend/src/views/accounts/composables/useAccountsQuery.ts
@@ -7,6 +7,18 @@ import { toast } from '@/components/base/BaseToast'
 import { usePagedQuery } from '@/composables/usePagedQuery'
 import { errorMessage } from '@/utils/async'
 
+type AccountRow = Awaited<ReturnType<typeof getAccounts>>['items'][number]
+type AccountSummary = Awaited<ReturnType<typeof getAccounts>>['summary']
+type AccountSummaryStatusKey = Exclude<keyof AccountSummary, 'total'>
+
+const summaryKeyByStatus = {
+  normal: 'normal',
+  quota_exhausted: 'quotaExhausted',
+  rate_limited: 'rateLimited',
+  disabled: 'disabled',
+  error: 'error',
+} as const satisfies Record<AccountRow['status'], AccountSummaryStatusKey>
+
 export function useAccountsQuery() {
   const searchQuery = shallowRef('')
   const providerQuery = shallowRef('')
@@ -64,6 +76,44 @@ export function useAccountsQuery() {
     void query.execute()
   }
 
+  function replaceAccount(updated: AccountRow) {
+    const index = query.items.value.findIndex(account => account.id === updated.id)
+    if (index < 0)
+      return false
+
+    const current = query.items.value[index]
+    if (!current)
+      return false
+
+    updateAccountSummary(current.status, updated.status)
+
+    if (statusQuery.value && statusQuery.value !== updated.status) {
+      query.items.value = query.items.value.filter(account => account.id !== updated.id)
+      query.total.value = Math.max(0, query.total.value - 1)
+      return false
+    }
+
+    const accounts = [...query.items.value]
+    accounts[index] = updated
+    query.items.value = accounts
+    return true
+  }
+
+  function updateAccountSummary(
+    previousStatus: AccountRow['status'],
+    nextStatus: AccountRow['status'],
+  ) {
+    if (previousStatus === nextStatus)
+      return
+
+    const previousKey = summaryKeyByStatus[previousStatus]
+    const nextKey = summaryKeyByStatus[nextStatus]
+    const summary = { ...accountSummary.value }
+    summary[previousKey] = Math.max(0, summary[previousKey] - 1)
+    summary[nextKey] += 1
+    accountSummary.value = summary
+  }
+
   watchDebounced(
     searchQuery,
     () => {
@@ -95,6 +145,7 @@ export function useAccountsQuery() {
     sort,
     accountSummary,
     accountPagination,
+    replaceAccount,
     handlePageChange,
     handlePageSizeChange,
     handleSortChange,
diff --git a/frontend/src/views/accounts/constants.ts b/frontend/src/views/accounts/constants.ts
index a5dfeb9ee..6c3d80438 100644
--- a/frontend/src/views/accounts/constants.ts
+++ b/frontend/src/views/accounts/constants.ts
@@ -1,4 +1,4 @@
-import type { getAccounts } from '@/api'
+import type { AccountErrorReason, AccountStatus, getAccounts } from '@/api'
 import type { BaseTableColumn } from '@/components/base/BaseTable/columns'
 import { clamp } from 'es-toolkit'
 import { providerDisplayName } from '@/utils/providers'
@@ -118,7 +118,7 @@ export const accountColumns = [
   },
 ] satisfies BaseTableColumn<AccountRow>[]
 
-export const statusLabels: Record<string, string> = {
+export const statusLabels: Record<AccountStatus, string> = {
   normal: '正常',
   quota_exhausted: '配额耗尽',
   rate_limited: '限流中',
@@ -126,7 +126,7 @@ export const statusLabels: Record<string, string> = {
   error: '错误',
 }
 
-export const statusTones: Record<string, 'success' | 'danger' | 'warning' | 'info' | 'normal'> = {
+export const statusTones: Record<AccountStatus, 'success' | 'danger' | 'warning' | 'info' | 'normal'> = {
   normal: 'success',
   quota_exhausted: 'warning',
   rate_limited: 'warning',
@@ -144,19 +144,19 @@ export const accountStatusFilterOptions = [
 ]
 
 /** `error` 分类下具体原因的展示文案（对应后端 `errorReason`）。 */
-export const errorReasonLabels: Record<string, string> = {
-  expired: '账号已过期',
-  token_expired: '访问令牌已过期',
-  invalid: '凭据已失效',
-  banned: '账号已封禁',
-  unknown: '状态未知',
+export const errorReasonLabels: Record<AccountErrorReason, string> = {
+  account_unverified: '账号身份尚未确认',
+  access_token_expired: 'Access Token 已过期',
+  credential_expired: '凭据已过期',
+  credential_invalid: '凭据无效',
+  account_banned: '账号不可用或已被封禁',
 }
 
 /**
  * 后端已派生互斥状态（正常 / 配额耗尽 / 限流中 / 已停用 / 错误）；
  * 前端只渲染，不再独立派生。
  */
-export function derivedAccountStatus(row: AccountRow): string {
+export function derivedAccountStatus(row: AccountRow): AccountStatus {
   return row.status
 }
 
diff --git a/frontend/src/views/accounts/index.vue b/frontend/src/views/accounts/index.vue
index d838d4493..40f595996 100644
--- a/frontend/src/views/accounts/index.vue
+++ b/frontend/src/views/accounts/index.vue
@@ -27,7 +27,6 @@ import { accountColumns, derivedAccountStatus } from './constants'
 
 const selectedIds = ref<Set<string>>(new Set())
 const {
-  totalAccounts,
   loading,
   accounts,
   loadAccounts,
@@ -37,6 +36,7 @@ const {
   sort,
   accountSummary,
   accountPagination,
+  replaceAccount,
   handlePageChange,
   handlePageSizeChange,
   handleSortChange,
@@ -67,17 +67,13 @@ const {
   handleExportAccounts,
   handleRefresh,
   handleRefreshQuota,
-  patchAccountStatus,
   handleToggleSchedule,
   scheduleActionLabel,
 } = useAccountMutations({
   accounts,
-  accountSummary,
-  statusQuery,
-  sort,
   selectedIds,
-  totalAccounts,
   reload: loadAccounts,
+  replaceAccount,
 })
 
 const {
@@ -99,9 +95,7 @@ const {
   openConnectionTest,
   handleRefreshConnectionTestModels,
   handleTestConnection,
-} = useAccountConnectionTest({
-  onAccountStatus: patchAccountStatus,
-})
+} = useAccountConnectionTest({ reload: loadAccounts })
 
 const {
   expandedAccountIds,
diff --git a/frontend/src/views/dashboard/components/AccountOverviewCard.vue b/frontend/src/views/dashboard/components/AccountOverviewCard.vue
index cfe9522d6..6936f8d31 100644
--- a/frontend/src/views/dashboard/components/AccountOverviewCard.vue
+++ b/frontend/src/views/dashboard/components/AccountOverviewCard.vue
@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import type { dashboardSnapshotView, MetricTone } from '../composables/presenter'
-import { CircleCheck, RefreshCw, ShieldAlert, TriangleAlert } from '@lucide/vue'
+import { CircleCheck, CircleOff, RefreshCw, ShieldAlert, TriangleAlert } from '@lucide/vue'
 import { clamp } from 'es-toolkit'
 
 import { computed } from 'vue'
@@ -82,17 +82,19 @@ const accountStatusCounts = computed(() => {
   const p = props.pool
   if (!p)
     return null
-  const active = p.active ?? 0
-  const refreshing = p.refreshing ?? 0
-  const quotaLimited = (p.rateLimited ?? 0) + (p.quotaExhausted ?? 0)
-  const pending = (p.expired ?? 0) + (p.invalid ?? 0) + (p.disabled ?? 0) + (p.banned ?? 0)
+  const normal = p.normal ?? 0
+  const quotaExhausted = p.quotaExhausted ?? 0
+  const rateLimited = p.rateLimited ?? 0
+  const disabled = p.disabled ?? 0
+  const error = p.error ?? 0
   return {
     total: p.total,
-    active,
-    refreshing,
-    quotaLimited,
-    pending,
-    unavailable: quotaLimited + pending,
+    normal,
+    quotaExhausted,
+    rateLimited,
+    disabled,
+    error,
+    unavailable: quotaExhausted + rateLimited + disabled + error,
   }
 })
 
@@ -101,54 +103,58 @@ const statusRows = computed(() => {
   const counts = accountStatusCounts.value
   if (!p || !counts) {
     return [
-      { label: '活跃账号', description: '暂无账号池观测', value: '—', tone: 'success', icon: CircleCheck },
-      { label: '刷新中', description: '暂无账号池观测', value: '—', tone: 'normal', icon: RefreshCw },
-      { label: '额度受限', description: '暂无账号池观测', value: '—', tone: 'warning', icon: TriangleAlert },
-      { label: '待处理', description: '暂无账号池观测', value: '—', tone: 'danger', icon: ShieldAlert },
+      { label: '正常', description: '暂无账号池观测', value: '—', tone: 'success', icon: CircleCheck },
+      { label: '配额耗尽', description: '暂无账号池观测', value: '—', tone: 'warning', icon: TriangleAlert },
+      { label: '限流中', description: '暂无账号池观测', value: '—', tone: 'normal', icon: RefreshCw },
+      { label: '已停用', description: '暂无账号池观测', value: '—', tone: 'normal', icon: CircleOff },
+      { label: '错误', description: '暂无账号池观测', value: '—', tone: 'danger', icon: ShieldAlert },
     ]
   }
-  const expired = p?.expired ?? 0
-  const invalid = p?.invalid ?? 0
-  const disabled = p?.disabled ?? 0
-  const banned = p?.banned ?? 0
 
   return [
     {
-      label: '活跃账号',
-      description: '可直接参与调度',
-      value: String(counts.active),
+      label: '正常',
+      description: '账号当前可用',
+      value: String(counts.normal),
       tone: 'success',
       icon: CircleCheck,
     },
     {
-      label: '刷新中',
-      description: '令牌自动刷新中',
-      value: String(counts.refreshing),
-      tone: 'normal',
-      icon: RefreshCw,
-    },
-    {
-      label: '额度受限',
-      description: '配额耗尽与限流中',
-      value: String(counts.quotaLimited),
+      label: '配额耗尽',
+      description: '账号额度已耗尽',
+      value: String(counts.quotaExhausted),
       tone: 'warning',
       icon: TriangleAlert,
     },
     {
-      label: '待处理',
-      description: `过期 ${expired} · 失效 ${invalid} · 禁用 ${disabled} · 封禁 ${banned}`,
-      value: String(counts.pending),
+      label: '限流中',
+      description: '账号请求暂时受限',
+      value: String(counts.rateLimited),
+      tone: 'normal',
+      icon: RefreshCw,
+    },
+    {
+      label: '已停用',
+      description: '账号已停用',
+      value: String(counts.disabled),
+      tone: 'normal',
+      icon: CircleOff,
+    },
+    {
+      label: '错误',
+      description: '账号状态异常',
+      value: String(counts.error),
       tone: 'danger',
       icon: ShieldAlert,
     },
   ]
 })
 
-const availabilityRate = computed(() => {
+const normalRate = computed(() => {
   const p = props.pool
   if (!p || p.total === 0)
     return '—'
-  return `${((p.active / p.total) * 100).toFixed(1)}%`
+  return `${((p.normal / p.total) * 100).toFixed(1)}%`
 })
 
 const statusBars = computed(() => {
@@ -156,10 +162,11 @@ const statusBars = computed(() => {
   if (!counts || counts.total === 0)
     return []
   return [
-    { pct: (counts.active / counts.total) * 100, cls: 'bg-(--cp-success)' },
-    { pct: (counts.refreshing / counts.total) * 100, cls: 'bg-(--cp-normal)' },
-    { pct: (counts.quotaLimited / counts.total) * 100, cls: 'bg-(--cp-warning)' },
-    { pct: (counts.pending / counts.total) * 100, cls: 'bg-(--cp-danger)' },
+    { pct: (counts.normal / counts.total) * 100, cls: 'bg-(--cp-success)' },
+    { pct: (counts.quotaExhausted / counts.total) * 100, cls: 'bg-(--cp-warning)' },
+    { pct: (counts.rateLimited / counts.total) * 100, cls: 'bg-(--cp-normal)' },
+    { pct: (counts.disabled / counts.total) * 100, cls: 'bg-(--cp-text-secondary)' },
+    { pct: (counts.error / counts.total) * 100, cls: 'bg-(--cp-danger)' },
   ].filter(b => b.pct > 0)
 })
 </script>
@@ -305,8 +312,8 @@ const statusBars = computed(() => {
           <div class="grid justify-items-end">
             <strong
               class="font-mono text-2xl leading-[1.05] font-heavy tabular-nums text-(--cp-success-text)"
-            >{{ availabilityRate }}</strong>
-            <span class="mt-0.5 text-xs leading-[1.15] font-bold text-(--cp-text-secondary)">可用率</span>
+            >{{ normalRate }}</strong>
+            <span class="mt-0.5 text-xs leading-[1.15] font-bold text-(--cp-text-secondary)">正常率</span>
           </div>
         </header>
 
@@ -326,11 +333,11 @@ const statusBars = computed(() => {
           </div>
         </div>
 
-        <div class="mt-6.5 grid h-65.5 w-full gap-2.5">
+        <div class="mt-5 grid h-67 w-full grid-rows-5 gap-2">
           <div
             v-for="row in statusRows"
             :key="row.label"
-            class="grid h-14.5 grid-cols-[28px_14px_minmax(0,1fr)_76px] items-center rounded-[14px] bg-(--cp-bg-subtle) px-3.5"
+            class="grid min-h-0 grid-cols-[28px_14px_minmax(0,1fr)_76px] items-center rounded-[14px] bg-(--cp-bg-subtle) px-3.5"
           >
             <span
               class="inline-flex size-7 items-center justify-center rounded-[9px]"