diff --git a/backend/crates/gateway-store/src/postgres/provider_accounts.rs b/backend/crates/gateway-store/src/postgres/provider_accounts.rs
index 626222444..a275572c2 100644
--- a/backend/crates/gateway-store/src/postgres/provider_accounts.rs
+++ b/backend/crates/gateway-store/src/postgres/provider_accounts.rs
@@ -630,7 +630,8 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
                      else availability_observed_at
                  end,
                  updated_at = case when enabled then greatest(now(), $6) else updated_at end
-             where id = $1 and credential_revision = $2",
+             where id = $1 and credential_revision = $2
+               and (availability_observed_at is null or availability_observed_at <= $6)",
         )
         .bind(update.account_id)
         .bind(to_i64(update.expected_revision.get())?)
@@ -675,7 +676,8 @@ impl ProviderAccountRepository for PgProviderAccountRepository {
             "update provider_accounts
              set provider_quota_json = $3, quota_observed_at = $4,
                  updated_at = greatest(now(), coalesce($4, now()))
-             where id = $1 and credential_revision = $2",
+             where id = $1 and credential_revision = $2
+               and ($4 is null or quota_observed_at is null or quota_observed_at <= $4)",
         )
         .bind(account_id)
         .bind(to_i64(expected_revision.get())?)
diff --git a/backend/crates/gateway-store/tests/postgres/provider_accounts.rs b/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
index 1fd9b430d..9e9589543 100644
--- a/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
+++ b/backend/crates/gateway-store/tests/postgres/provider_accounts.rs
@@ -111,6 +111,97 @@ async fn core_quota_batch_reads_only_observed_accounts_in_one_contract_call() {
     database.close().await;
 }
 
+#[tokio::test]
+async fn delayed_provider_observations_cannot_overwrite_newer_state_or_quota() {
+    let Some(database) = TestDatabase::create("provider_account_observation_fence").await else {
+        return;
+    };
+    let repository = PgProviderAccountRepository::new(database.pool.clone());
+    let account_id = ProviderAccountId::new("acct_observation_fence").expect("account id");
+    repository
+        .insert_provider_account(account(account_id.as_str(), "user-observation-fence"))
+        .await
+        .expect("insert observation fence fixture");
+    let revision = CredentialRevision::new(1).expect("revision");
+    let newer = SystemTime::now()
+        .checked_add(Duration::from_secs(60))
+        .expect("newer observation time");
+    let older = newer
+        .checked_sub(Duration::from_secs(30))
+        .expect("older observation time");
+
+    let quota = |marker: &str, observed_at| QuotaObservation {
+        account_id: account_id.clone(),
+        expected_revision: revision,
+        quota: Some(OpaqueProviderData::new(
+            json!({"marker": marker})
+                .as_object()
+                .expect("quota object")
+                .clone(),
+        )),
+        observed_at: Some(observed_at),
+    };
+    assert_eq!(
+        repository
+            .compare_and_swap_quota(quota("newer", newer))
+            .await
+            .expect("persist newer quota"),
+        QuotaWriteOutcome::Updated
+    );
+    assert_eq!(
+        repository
+            .compare_and_swap_quota(quota("older", older))
+            .await
+            .expect("reject older quota"),
+        QuotaWriteOutcome::Conflict
+    );
+
+    repository
+        .apply_state_change(AccountStateChange {
+            account_id: account_id.clone(),
+            expected_revision: revision,
+            availability: AccountAvailability::QuotaExhausted,
+            reason: Some("quota_exhausted".to_owned()),
+            cooldown_until: Some(newer),
+            observed_at: newer,
+        })
+        .await
+        .expect("persist newer account state");
+    assert!(
+        repository
+            .apply_state_change(AccountStateChange {
+                account_id: account_id.clone(),
+                expected_revision: revision,
+                availability: AccountAvailability::Ready,
+                reason: None,
+                cooldown_until: None,
+                observed_at: older,
+            })
+            .await
+            .is_err(),
+        "a delayed state observation must conflict"
+    );
+
+    let current = repository
+        .get_account(&account_id)
+        .await
+        .expect("load fenced account")
+        .expect("fenced account");
+    assert_eq!(current.availability(), AccountAvailability::QuotaExhausted);
+    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"
+    );
+
+    database.close().await;
+}
+
 #[tokio::test]
 async fn terminal_admin_list_filters_and_sorts_before_pagination_with_retained_usage() {
     let Some(database) = TestDatabase::create("provider_account_terminal_list").await else {
diff --git a/backend/crates/providers/openai/src/admin.rs b/backend/crates/providers/openai/src/admin.rs
index ecae3a396..dff3d5f0f 100644
--- a/backend/crates/providers/openai/src/admin.rs
+++ b/backend/crates/providers/openai/src/admin.rs
@@ -25,8 +25,9 @@ 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::{
-    CredentialRevision, LoadedCredential, NewProviderAccount, OpaqueProviderData,
-    PlaintextCredential, ProviderAccount, ProviderAccountId, ProviderAccountStore,
+    AccountAvailability, CredentialRevision, LoadedCredential, NewProviderAccount,
+    OpaqueProviderData, PlaintextCredential, ProviderAccount, ProviderAccountId,
+    ProviderAccountStore,
 };
 use gateway_core::error::StoreErrorKind;
 use gateway_core::operation::{GenerateRequest, Operation, ProtocolPayload};
@@ -458,21 +459,23 @@ impl ProviderAdmin for OpenAiAdminProvider {
             refresh,
             rolling_usage: _,
         } = request;
-        self.account(&account_id).await?;
+        let mut account = self.account(&account_id).await?;
         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)
                 .await
                 .map_err(map_quota_error)?
         };
-        Ok(snapshot.map_or_else(empty_quota, project_quota))
+        Ok(project_quota(snapshot, &account))
     }
 
     async fn models(
@@ -746,7 +749,18 @@ fn empty_quota() -> ProviderQuota {
     }
 }
 
-fn project_quota(snapshot: CodexAccountQuotaSnapshot) -> ProviderQuota {
+fn project_quota(
+    snapshot: Option<CodexAccountQuotaSnapshot>,
+    account: &ProviderAccount,
+) -> ProviderQuota {
+    let mut quota = snapshot.map_or_else(empty_quota, project_quota_snapshot);
+    if account.availability() == AccountAvailability::QuotaExhausted {
+        force_confirmed_exhaustion_projection(&mut quota, account.cooldown_until());
+    }
+    quota
+}
+
+fn project_quota_snapshot(snapshot: CodexAccountQuotaSnapshot) -> ProviderQuota {
     let mut provider_data = Map::new();
     provider_data.insert(
         "remaining_percent".to_owned(),
@@ -799,6 +813,68 @@ fn project_quota(snapshot: CodexAccountQuotaSnapshot) -> ProviderQuota {
     }
 }
 
+fn force_confirmed_exhaustion_projection(
+    quota: &mut ProviderQuota,
+    cooldown_until: Option<SystemTime>,
+) {
+    // 真实 429 对“当前已耗尽”的证明强于可能延迟结算的 usage 文档。这里只覆盖
+    // 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.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)),
+        ]),
+    )));
+    let reset_at = cooldown_until.map(DateTime::<Utc>::from);
+    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,
+            window_seconds: None,
+            used_percent: Some(100.0),
+            reset_at,
+            local_usage: None,
+            provider_data: None,
+        });
+        return;
+    }
+
+    let matched_reset = reset_at.and_then(|reset_at| {
+        quota
+            .windows
+            .iter()
+            .enumerate()
+            .filter_map(|(index, window)| {
+                let distance = window.reset_at.map(|window_reset| {
+                    (window_reset.timestamp() - reset_at.timestamp()).unsigned_abs()
+                })?;
+                Some((index, distance))
+            })
+            .min_by_key(|(_, distance)| *distance)
+            .map(|(index, _)| index)
+    });
+    let index = matched_reset
+        .or_else(|| {
+            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);
+}
+
 const fn quota_group(kind: CodexQuotaWindowKind) -> &'static str {
     match kind {
         CodexQuotaWindowKind::Monthly => "monthly",
diff --git a/backend/crates/providers/openai/src/credential/quota.rs b/backend/crates/providers/openai/src/credential/quota.rs
index a02e8c586..d32e442c9 100644
--- a/backend/crates/providers/openai/src/credential/quota.rs
+++ b/backend/crates/providers/openai/src/credential/quota.rs
@@ -194,6 +194,19 @@ pub struct CodexQuotaSyncSummary {
     pub stale: u64,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum QuotaRecoveryEvidence {
+    SuccessfulResponse,
+    RefreshedSnapshot { confirms_recovery: bool },
+    PostFailureSnapshot,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum QuotaRefreshMode {
+    Reconcile,
+    AfterConfirmedFailure,
+}
+
 impl CodexQuotaSyncSummary {
     #[must_use]
     pub const fn has_operational_failures(self) -> bool {
@@ -636,9 +649,20 @@ impl CodexCredentialQuotaService {
             let observed_at = SystemTime::now();
             match self.fetch_usage_with_recovery(&client, &account).await {
                 Ok(FetchedCodexQuota { account, value }) => {
+                    let previous_snapshot = observations
+                        .as_ref()
+                        .and_then(|observations| observations.get(account.id()))
+                        .filter(|observation| observation.expected_revision == account.revision())
+                        .and_then(quota_snapshot_from_observation);
                     // 单账号解析或落库失败只影响该账号；其余账号继续同步。
                     if let Err(error) = self
-                        .apply_fetched_quota(&account, &value, observed_at, &mut summary)
+                        .apply_fetched_quota(
+                            &account,
+                            &value,
+                            observed_at,
+                            previous_snapshot.as_ref(),
+                            &mut summary,
+                        )
                         .await
                     {
                         summary.transient += 1;
@@ -753,9 +777,16 @@ impl CodexCredentialQuotaService {
         account: &ProviderAccount,
         value: &Value,
         observed_at: SystemTime,
+        previous_snapshot: Option<&CodexAccountQuotaSnapshot>,
         summary: &mut CodexQuotaSyncSummary,
     ) -> Result<(), CodexCredentialQuotaError> {
-        let fact = parse_codex_quota_usage(value)?;
+        let snapshot = parse_account_quota_snapshot(
+            account.id().clone(),
+            account.revision(),
+            observed_at,
+            value,
+        )?;
+        let fact = snapshot.fact();
         let object = value
             .as_object()
             .cloned()
@@ -793,6 +824,9 @@ impl CodexCredentialQuotaService {
             current.cooldown_until(),
             fact,
             SystemTime::now(),
+            QuotaRecoveryEvidence::RefreshedSnapshot {
+                confirms_recovery: quota_snapshot_confirms_recovery(previous_snapshot, &snapshot),
+            },
         ) {
             let _ = self
                 .repository
@@ -859,6 +893,7 @@ impl CodexCredentialQuotaService {
             current.cooldown_until(),
             fact,
             observed_at,
+            QuotaRecoveryEvidence::SuccessfulResponse,
         ) {
             self.repository
                 .apply_state(
@@ -934,6 +969,24 @@ impl CodexCredentialQuotaService {
     pub async fn refresh_account(
         &self,
         account_id: &ProviderAccountId,
+    ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
+        self.refresh_account_with_mode(account_id, QuotaRefreshMode::Reconcile)
+            .await
+    }
+
+    /// 真实限额失败后的异步刷新只补齐展示快照，不允许同一轮陈旧 usage 撤销失败状态。
+    pub(crate) async fn refresh_account_after_failure(
+        &self,
+        account_id: &ProviderAccountId,
+    ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
+        self.refresh_account_with_mode(account_id, QuotaRefreshMode::AfterConfirmedFailure)
+            .await
+    }
+
+    async fn refresh_account_with_mode(
+        &self,
+        account_id: &ProviderAccountId,
+        mode: QuotaRefreshMode,
     ) -> Result<CodexAccountQuotaSnapshot, CodexCredentialQuotaError> {
         let account = self
             .store
@@ -941,6 +994,7 @@ impl CodexCredentialQuotaService {
             .await?
             .filter(|account| account.provider().as_str() == "openai")
             .ok_or(CodexCredentialQuotaError::NotFound)?;
+        let previous_snapshot = self.read_snapshot_for(&account).await?;
         let observed_at = SystemTime::now();
         if !access_token_is_current(&account, observed_at) {
             return Err(CodexCredentialQuotaError::CredentialRefreshRequired);
@@ -1017,6 +1071,17 @@ impl CodexCredentialQuotaService {
             current.cooldown_until(),
             snapshot.fact(),
             SystemTime::now(),
+            match mode {
+                QuotaRefreshMode::AfterConfirmedFailure => {
+                    QuotaRecoveryEvidence::PostFailureSnapshot
+                }
+                QuotaRefreshMode::Reconcile => QuotaRecoveryEvidence::RefreshedSnapshot {
+                    confirms_recovery: quota_snapshot_confirms_recovery(
+                        previous_snapshot.as_ref(),
+                        &snapshot,
+                    ),
+                },
+            },
         ) {
             self.repository
                 .apply_state(
@@ -1239,9 +1304,13 @@ fn quota_success_state(
     cooldown_until: Option<SystemTime>,
     fact: CodexQuotaFact,
     now: SystemTime,
+    recovery_evidence: QuotaRecoveryEvidence,
 ) -> Option<(AccountAvailability, Option<SystemTime>)> {
     if fact.exhausted() {
-        let observed_cooldown = fact.resets_at().map(SystemTime::from).or(cooldown_until);
+        let observed_cooldown = match (fact.resets_at().map(SystemTime::from), cooldown_until) {
+            (Some(observed), Some(confirmed)) => Some(observed.max(confirmed)),
+            (observed, confirmed) => observed.or(confirmed),
+        };
         return (current != AccountAvailability::QuotaExhausted
             || cooldown_until != observed_cooldown)
             .then_some((AccountAvailability::QuotaExhausted, observed_cooldown));
@@ -1251,8 +1320,13 @@ fn quota_success_state(
         AccountAvailability::Invalid
         | AccountAvailability::Expired
         | AccountAvailability::Banned
-        | AccountAvailability::Unknown
-        | AccountAvailability::QuotaExhausted => Some(AccountAvailability::Ready),
+        | AccountAvailability::Unknown => Some(AccountAvailability::Ready),
+        AccountAvailability::QuotaExhausted
+            if !quota_recovery_confirmed(recovery_evidence, cooldown_until, now) =>
+        {
+            None
+        }
+        AccountAvailability::QuotaExhausted => Some(AccountAvailability::Ready),
         AccountAvailability::Ready => None,
         AccountAvailability::Cooldown
             if cooldown_until.is_some_and(|cooldown_until| cooldown_until <= now) =>
@@ -1264,6 +1338,59 @@ fn quota_success_state(
     availability.map(|availability| (availability, None))
 }
 
+fn quota_recovery_confirmed(
+    evidence: QuotaRecoveryEvidence,
+    cooldown_until: Option<SystemTime>,
+    now: SystemTime,
+) -> bool {
+    if cooldown_until.is_some_and(|cooldown_until| cooldown_until <= now) {
+        return true;
+    }
+    match evidence {
+        QuotaRecoveryEvidence::SuccessfulResponse => true,
+        QuotaRecoveryEvidence::RefreshedSnapshot { confirms_recovery } => confirms_recovery,
+        QuotaRecoveryEvidence::PostFailureSnapshot => false,
+    }
+}
+
+fn quota_snapshot_confirms_recovery(
+    previous: Option<&CodexAccountQuotaSnapshot>,
+    current: &CodexAccountQuotaSnapshot,
+) -> bool {
+    if current.fact().exhausted() {
+        return false;
+    }
+    let Some(previous) = previous else {
+        return false;
+    };
+    if previous
+        .fact()
+        .remaining_percent()
+        .zip(current.fact().remaining_percent())
+        .is_some_and(|(previous, current)| current > previous)
+    {
+        return true;
+    }
+
+    // 单窗口账号可以用同一窗口的用量回落或 reset 前移证明上游提前翻新；多窗口
+    // 无法从账号级 429 确认具体受限窗口，保守等待整体剩余额度改善或真实请求成功。
+    let ([previous], [current]) = (previous.windows(), current.windows()) else {
+        return false;
+    };
+    if previous.key() != current.key() {
+        return false;
+    }
+    let usage_recovered = previous
+        .used_percent()
+        .zip(current.used_percent())
+        .is_some_and(|(previous, current)| current < previous);
+    let window_advanced = previous
+        .reset_at()
+        .zip(current.reset_at())
+        .is_some_and(|(previous, current)| current > previous);
+    usage_recovered || window_advanced
+}
+
 fn quota_state_transition(
     error: &CodexClientError,
     observed_at: SystemTime,
diff --git a/backend/crates/providers/openai/src/provider.rs b/backend/crates/providers/openai/src/provider.rs
index a5f4fd2c5..75c807977 100644
--- a/backend/crates/providers/openai/src/provider.rs
+++ b/backend/crates/providers/openai/src/provider.rs
@@ -2009,15 +2009,15 @@ fn schedule_authoritative_quota_refresh_after_failure(
     account: &ProviderAccount,
 ) {
     // 限额错误可以确认账号状态，但 Responses 事件中的 used_percent 可能仍停在上一结算点。
-    // usage 快照在后台补齐，不能阻塞原始失败响应。先等待 2 秒让上游结算，
-    // 再查询；5 秒仅限制实际查询自身。
+    // usage 快照在后台补齐展示基线，不得撤销同一轮真实失败，也不能阻塞原始响应。
+    // 先等待 2 秒让上游结算，再查询；5 秒仅限制实际查询自身。
     let quota = Arc::clone(quota);
     let account_id = account.id().clone();
     drop(tokio::spawn(async move {
         tokio::time::sleep(QUOTA_FAILURE_REFRESH_DELAY).await;
         match tokio::time::timeout(
             QUOTA_FAILURE_REFRESH_TIMEOUT,
-            quota.refresh_account(&account_id),
+            quota.refresh_account_after_failure(&account_id),
         )
         .await
         {
diff --git a/backend/crates/providers/openai/tests/admin.rs b/backend/crates/providers/openai/tests/admin.rs
index 589ef94ba..7106c8960 100644
--- a/backend/crates/providers/openai/tests/admin.rs
+++ b/backend/crates/providers/openai/tests/admin.rs
@@ -20,8 +20,8 @@ use gateway_admin::model::provider_credentials::{
 use gateway_admin::model::{MutationActor, MutationContext, Revision};
 use gateway_admin::ports::provider::ProviderAdminErrorKind;
 use gateway_core::engine::credential::{
-    CredentialRevision, OpaqueProviderData, ProviderAccount, ProviderAccountId,
-    ProviderAccountStore, QuotaObservation,
+    AccountAvailability as CoreAccountAvailability, AccountStateChange, CredentialRevision,
+    OpaqueProviderData, ProviderAccount, ProviderAccountId, ProviderAccountStore, QuotaObservation,
 };
 use gateway_core::operation::{GenerateRequest, Operation, ProtocolPayload};
 use gateway_core::provider_ports::{
@@ -503,6 +503,108 @@ async fn openai_admin_provider_projects_codex_additional_limit_as_the_primary_qu
     assert_eq!(monthly[0].used_percent, Some(2.0));
 }
 
+#[tokio::test]
+async fn openai_admin_projects_confirmed_quota_exhaustion_as_full_without_mutating_raw_usage() {
+    let store = Arc::new(MemoryAccountStore::default());
+    let account_id = "acct_admin_confirmed_exhaustion";
+    store
+        .seed_oauth_credential(ImportCodexOAuthCredential {
+            account_id: account_id.to_owned(),
+            name: "admin confirmed exhaustion".to_owned(),
+            secret: secret("admin-confirmed-exhaustion-access"),
+            verified_account: profile("chatgpt-admin-confirmed-exhaustion"),
+            next_refresh_at: Some(Utc::now() + chrono::Duration::minutes(30)),
+            enabled: true,
+        })
+        .await;
+    let account = store.account(account_id).expect("stored account");
+    let reset_at = 1_900_000_000_u64;
+    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": 86, "reset_at": reset_at}
+                    }
+                })
+                .as_object()
+                .expect("quota object")
+                .clone(),
+            )),
+            observed_at: Some(SystemTime::now()),
+        })
+        .await
+        .expect("persist raw quota");
+    store
+        .apply_state_change(AccountStateChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            availability: CoreAccountAvailability::QuotaExhausted,
+            reason: Some("usage_limit_exhausted".to_owned()),
+            cooldown_until: Some(SystemTime::UNIX_EPOCH + Duration::from_secs(reset_at)),
+            observed_at: SystemTime::now(),
+        })
+        .await
+        .expect("mark account exhausted");
+    let config = valid_config();
+    let bundle = provider_openai::initialize(
+        config.config.clone(),
+        provider_ports_with(Arc::clone(&store), Arc::new(TestOAuthPending::default())),
+    )
+    .await
+    .expect("OpenAI bundle");
+
+    let exhausted = bundle
+        .admin_provider()
+        .quota(ProviderQuotaRequest {
+            account_id: account.id().clone(),
+            refresh: false,
+            rolling_usage: None,
+        })
+        .await
+        .expect("project exhausted quota");
+
+    assert_eq!(exhausted.windows.len(), 1);
+    assert_eq!(exhausted.windows[0].used_percent, Some(100.0));
+    let raw = store
+        .get_quotas(std::slice::from_ref(account.id()))
+        .await
+        .expect("read raw quota")
+        .pop()
+        .expect("raw quota");
+    assert_eq!(
+        raw.quota.expect("raw document").expose_to_provider()["rate_limit"]["primary_window"]["used_percent"],
+        86
+    );
+
+    store
+        .apply_state_change(AccountStateChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            availability: CoreAccountAvailability::Ready,
+            reason: None,
+            cooldown_until: None,
+            observed_at: SystemTime::now(),
+        })
+        .await
+        .expect("recover account");
+    let recovered = bundle
+        .admin_provider()
+        .quota(ProviderQuotaRequest {
+            account_id: account.id().clone(),
+            refresh: false,
+            rolling_usage: None,
+        })
+        .await
+        .expect("project recovered quota");
+
+    assert_eq!(recovered.windows[0].used_percent, Some(86.0));
+}
+
 #[tokio::test]
 async fn openai_admin_provider_rejects_unprepared_mutations_before_store_commit() {
     let store = Arc::new(MemoryAccountStore::default());
diff --git a/backend/crates/providers/openai/tests/credential/quota.rs b/backend/crates/providers/openai/tests/credential/quota.rs
index 40fe85eba..21a543feb 100644
--- a/backend/crates/providers/openai/tests/credential/quota.rs
+++ b/backend/crates/providers/openai/tests/credential/quota.rs
@@ -498,6 +498,38 @@ async fn manual_quota_refresh_updates_account_state_from_provider_response() {
         AccountAvailability::QuotaExhausted
     );
 
+    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": 100, "reset_at": 1_900_000_000}
+            }
+        })))
+        .mount(&server)
+        .await;
+
+    let stale = service
+        .refresh_account(account.id())
+        .await
+        .expect("refresh contradictory full quota");
+
+    assert!(!stale.fact().exhausted());
+    assert_eq!(
+        store
+            .account(account_id)
+            .expect("account after contradictory quota")
+            .availability(),
+        AccountAvailability::QuotaExhausted,
+        "an unchanged usage window cannot override a confirmed quota failure"
+    );
+
     server.reset().await;
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
@@ -1018,6 +1050,118 @@ async fn periodic_quota_synchronization_rechecks_exhausted_accounts_without_wait
     assert_eq!(repeated, CodexQuotaSyncSummary::default());
 }
 
+#[tokio::test]
+async fn periodic_quota_synchronization_requires_a_real_snapshot_improvement_to_recover() {
+    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": 86, "reset_at": reset_at}
+                    }
+                })
+                .as_object()
+                .expect("quota object")
+                .clone(),
+            )),
+            observed_at: Some(SystemTime::now()),
+        })
+        .await
+        .expect("seed post-failure quota snapshot");
+    store
+        .apply_state_change(AccountStateChange {
+            account_id: account.id().clone(),
+            expected_revision: account.revision(),
+            availability: AccountAvailability::QuotaExhausted,
+            reason: Some("usage_limit_exhausted".to_owned()),
+            cooldown_until: SystemTime::now().checked_add(Duration::from_secs(24 * 60 * 60)),
+            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": 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");
+
+    assert_eq!(unchanged.updated, 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": {
+                "allowed": true,
+                "limit_reached": false,
+                "primary_window": {"used_percent": 20, "reset_at": reset_at}
+            }
+        })))
+        .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 improved = next_cycle
+        .synchronize()
+        .await
+        .expect("improved quota recheck");
+
+    assert_eq!(improved.updated, 1);
+    assert_eq!(
+        store
+            .account(account_id)
+            .expect("account after improved snapshot")
+            .availability(),
+        AccountAvailability::Ready
+    );
+}
+
 #[tokio::test]
 async fn periodic_quota_synchronization_throttles_the_same_exhausted_account() {
     let store = Arc::new(MemoryAccountStore::default());
diff --git a/backend/crates/providers/openai/tests/provider/contract.rs b/backend/crates/providers/openai/tests/provider/contract.rs
index dc08539f2..e9848fbc3 100644
--- a/backend/crates/providers/openai/tests/provider/contract.rs
+++ b/backend/crates/providers/openai/tests/provider/contract.rs
@@ -1036,15 +1036,16 @@ async fn usage_limit_failure_returns_promptly_and_refreshes_the_authoritative_qu
     Mock::given(method("GET"))
         .and(path("/api/codex/usage"))
         .and(header("authorization", format!("Bearer at-{account_id}")))
-        // 限额错误本身只能确认状态；这里必须覆盖上一帧被动观察到的 99%。
+        // 生产环境会短暂返回互相矛盾的快照：数字已到 100%，但布尔位仍声称可用。
+        // 后台同步应覆盖展示数据，不能据此撤销真实请求已经确认的额度耗尽。
         .respond_with(
             ResponseTemplate::new(200)
                 // 验证后台 usage 同步不能把原始的额度错误响应拖到查询完成之后。
                 .set_delay(Duration::from_millis(750))
                 .set_body_json(json!({
                     "rate_limit": {
-                        "allowed": false,
-                        "limit_reached": true,
+                        "allowed": true,
+                        "limit_reached": false,
                         "primary_window": {"used_percent": 100, "reset_at": 1_900_000_000}
                     }
                 })),
@@ -1142,6 +1143,14 @@ async fn usage_limit_failure_returns_promptly_and_refreshes_the_authoritative_qu
             .count(),
         1
     );
+    assert_eq!(
+        store
+            .account(account_id)
+            .expect("account after stale full usage refresh")
+            .availability(),
+        AccountAvailability::QuotaExhausted,
+        "a contradictory full usage snapshot must not unlock a confirmed exhausted account"
+    );
 }
 
 #[tokio::test]
diff --git a/backend/crates/providers/openai/tests/support.rs b/backend/crates/providers/openai/tests/support.rs
index 84e5735a5..7c4f3cafd 100644
--- a/backend/crates/providers/openai/tests/support.rs
+++ b/backend/crates/providers/openai/tests/support.rs
@@ -36,6 +36,7 @@ struct StoredAccount {
     account: ProviderAccount,
     credential: gateway_core::engine::credential::PlaintextCredential,
     quota: Option<QuotaObservation>,
+    state_observed_at: Option<SystemTime>,
 }
 
 #[derive(Default)]
@@ -129,6 +130,7 @@ impl ProviderAccountStore for MemoryAccountStore {
                 account: input.account,
                 credential: input.credential,
                 quota: None,
+                state_observed_at: None,
             },
         );
         Ok(())
@@ -260,6 +262,15 @@ impl ProviderAccountStore for MemoryAccountStore {
         if stored.account.revision() != observation.expected_revision {
             return Ok(QuotaWriteOutcome::Conflict);
         }
+        if stored
+            .quota
+            .as_ref()
+            .and_then(|quota| quota.observed_at)
+            .zip(observation.observed_at)
+            .is_some_and(|(current, incoming)| current > incoming)
+        {
+            return Ok(QuotaWriteOutcome::Conflict);
+        }
         stored.quota = Some(observation);
         Ok(QuotaWriteOutcome::Updated)
     }
@@ -272,6 +283,12 @@ impl ProviderAccountStore for MemoryAccountStore {
         if stored.account.revision() != change.expected_revision {
             return Err(store_error(StoreErrorKind::Conflict));
         }
+        if stored
+            .state_observed_at
+            .is_some_and(|current| current > change.observed_at)
+        {
+            return Err(store_error(StoreErrorKind::Conflict));
+        }
         stored.account = rebuild_account(
             &stored.account,
             AccountRebuild {
@@ -285,6 +302,7 @@ impl ProviderAccountStore for MemoryAccountStore {
                 profile: None,
             },
         );
+        stored.state_observed_at = Some(change.observed_at);
         Ok(())
     }