diff --git a/backend/crates/gateway-protocol/src/anthropic/mod.rs b/backend/crates/gateway-protocol/src/anthropic/mod.rs
index fcd611635..a2f98d68b 100644
--- a/backend/crates/gateway-protocol/src/anthropic/mod.rs
+++ b/backend/crates/gateway-protocol/src/anthropic/mod.rs
@@ -24,6 +24,7 @@ pub use stream::{
     MessagesAccumulator, MessagesToResponsesStream, ResponsesToMessagesStream,
     message_to_stream_events,
 };
+pub use thinking::messages_request_effort;
 pub use usage::MessageUsage;
 
 /// Messages 载荷的协议标识
diff --git a/backend/crates/gateway-protocol/src/anthropic/thinking.rs b/backend/crates/gateway-protocol/src/anthropic/thinking.rs
index f9f5b8f09..0299e6913 100644
--- a/backend/crates/gateway-protocol/src/anthropic/thinking.rs
+++ b/backend/crates/gateway-protocol/src/anthropic/thinking.rs
@@ -1,16 +1,22 @@
-//! 按目标模型能力映射推理等级与预算；未知兼容上游沿用 CPA 手动预算
+//! 提取 Messages 显式 effort，并按目标模型能力映射推理等级与预算
 
 use serde_json::{Map, Value, json};
 
 use super::MessagesModelCapabilities;
 
-pub(super) fn to_responses(request: &Map<String, Value>) -> Value {
-    let configured = request
+/// 返回客户端显式设置的 effort，预算与默认档位由转换器单独处理
+#[must_use]
+pub fn messages_request_effort(request: &Map<String, Value>) -> Option<&str> {
+    request
         .get("output_config")
         .and_then(|value| value.get("effort"))
         .and_then(Value::as_str)
-        .map(|value| value.trim().to_ascii_lowercase())
-        .filter(|value| !value.is_empty());
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+}
+
+pub(super) fn to_responses(request: &Map<String, Value>) -> Value {
+    let configured = messages_request_effort(request).map(str::to_ascii_lowercase);
     let thinking = request.get("thinking");
     let effort = match thinking
         .and_then(|value| value.get("type"))
diff --git a/backend/crates/providers/openai/src/provider/mod.rs b/backend/crates/providers/openai/src/provider/mod.rs
index dd5860553..199c7beff 100644
--- a/backend/crates/providers/openai/src/provider/mod.rs
+++ b/backend/crates/providers/openai/src/provider/mod.rs
@@ -504,6 +504,16 @@ impl Provider for CodexProvider {
                 ..Default::default()
             };
         };
+        let payload = request.protocol_payload();
+        if payload.protocol() == gateway_protocol::anthropic::ANTHROPIC_PROTOCOL {
+            return ProviderRequestObservation {
+                reasoning_effort: gateway_protocol::anthropic::messages_request_effort(
+                    payload.body(),
+                )
+                .map(str::to_owned),
+                ..Default::default()
+            };
+        }
         let Ok(encoded) = encode_generate_request(request, "observability", None) else {
             return ProviderRequestObservation::default();
         };
diff --git a/backend/crates/providers/openai/tests/provider/contract/messages.rs b/backend/crates/providers/openai/tests/provider/contract/messages.rs
index 0e196db44..cbfcc7085 100644
--- a/backend/crates/providers/openai/tests/provider/contract/messages.rs
+++ b/backend/crates/providers/openai/tests/provider/contract/messages.rs
@@ -29,6 +29,7 @@ async fn seed(store: &Arc<MemoryAccountStore>, server: &MockServer, protocol: Ap
 fn messages_operation(stream: bool) -> Operation {
     let body = json!({
         "model":"gpt-5.4", "max_tokens":128, "stream":stream,
+        "thinking":{"type":"adaptive"}, "output_config":{"effort":"xhigh"},
         "messages":[
             {"role":"assistant","content":[{"type":"thinking","thinking":"prior thought","signature":"real-native-signature"},{"type":"text","text":"before"}]},
             {"role":"user","content":"hello"},
@@ -51,6 +52,51 @@ fn messages_operation(stream: bool) -> Operation {
     ))
 }
 
+#[test]
+fn messages_request_observation_preserves_explicit_effort_without_inventing_defaults() {
+    let store = Arc::new(MemoryAccountStore::default());
+    let provider = provider(&store);
+    let client = ClientApiKeyId::new("key_messages_observation").unwrap();
+    for (options, expected) in [
+        (json!({"output_config":{"effort":"xhigh"}}), Some("xhigh")),
+        (
+            json!({"thinking":{"type":"adaptive"},"output_config":{"effort":"low"}}),
+            Some("low"),
+        ),
+        (
+            json!({"thinking":{"type":"disabled"},"output_config":{"effort":"high"}}),
+            Some("high"),
+        ),
+        (
+            json!({"output_config":{"effort":" Future-Level "}}),
+            Some("Future-Level"),
+        ),
+        (json!({"output_config":{"effort":" "}}), None),
+        (json!({"output_config":{"effort":null}}), None),
+        (json!({"output_config":{"effort":42}}), None),
+        (json!({"thinking":{"type":"adaptive"}}), None),
+        (
+            json!({"thinking":{"type":"enabled","budget_tokens":32768}}),
+            None,
+        ),
+        (json!({}), None),
+    ] {
+        let mut body = json!({"model":"gpt-5.4","max_tokens":128,"messages":[{"role":"user","content":"hello"}]});
+        body.as_object_mut()
+            .unwrap()
+            .extend(options.as_object().unwrap().clone());
+        let operation = Operation::Generate(GenerateRequest::from_protocol_payload(
+            ProtocolPayload::json_object("anthropic", body.as_object().unwrap().clone()).unwrap(),
+        ));
+        let observation = provider.request_observation(&operation, &client);
+        assert_eq!(
+            observation.reasoning_effort.as_deref(),
+            expected,
+            "{options}"
+        );
+    }
+}
+
 #[tokio::test]
 async fn final_usage_before_truncation_keeps_only_explicitly_priceable_cost() {
     for (priced, long_cache, fast) in [
@@ -174,7 +220,18 @@ async fn native_messages_preserve_json_sse_headers_and_real_signatures() {
             .await;
         let operation = messages_operation(streaming);
         let original = operation.middleware_body().unwrap();
-        let mut stream = provider(&store)
+        let provider = provider(&store);
+        assert_eq!(
+            provider
+                .request_observation(
+                    &operation,
+                    &ClientApiKeyId::new("key_messages_native").unwrap()
+                )
+                .reasoning_effort
+                .as_deref(),
+            Some("xhigh")
+        );
+        let mut stream = provider
             .execute(
                 planned_request("openai", operation),
                 context("req_messages_native", CancellationToken::new()),
@@ -290,6 +347,8 @@ async fn messages_and_responses_translate_with_target_header_boundaries() {
                 assert!(!headers.contains_key(name));
             }
         } else {
+            let body: Value = serde_json::from_slice(&requests[0].body).unwrap();
+            assert_eq!(body["reasoning"]["effort"], "xhigh");
             for name in [
                 "anthropic-version",
                 "anthropic-beta",
diff --git a/docs/api.md b/docs/api.md
index 92a439447..32647b232 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -2841,6 +2841,9 @@ OpenAI 推理强度优先取 `input` 中最后一条 `type: "configuration_updat
 原生续接未再次更新时沿用已关联响应的配置，否则取请求顶层 `reasoning.effort`。
 该字段是请求观测，不改写上游请求；网关未持有的续接历史无法用于推断档位
 
+Messages 推理强度取请求顶层 `output_config.effort` 的非空字符串，保留客户端设置的档位。
+未显式设置时保持未知，不根据 `thinking.budget_tokens` 或模型默认值推断；该记录不代表上游最终执行的档位
+
 首页趋势、请求健康与热点诊断统一口径：错误为服务失败与未完成之和，成功率为 `成功 /（成功 + 错误）`
 已恢复记录、客户端取消与调用方错误不计入，进行中不参与比例；调用方错误仅指失败终态的 4xx，不含取消请求的 499
 无有效样本时，成功率与错误率返回 `null`，趋势线保留断点