diff --git a/backend-integration/api-proxy.js b/backend-integration/api-proxy.js
index 94734a3b..d4821948 100644
--- a/backend-integration/api-proxy.js
+++ b/backend-integration/api-proxy.js
@@ -413,15 +413,17 @@ async function handleChat(req, res) {
       recordProxyFailure(curProv);
       console.error(`[代理] ${curProv} 请求失败: ${err.message}`);
 
-      if (isLastAttempt && !res.headersSent) {
+      // If headers already sent (partial streaming started), can't switch provider
+      if (res.headersSent) return;
+
+      if (isLastAttempt) {
         jsonResponse(res, 502, {
           error: true,
           code: 'ALL_PROVIDERS_FAILED',
           message: '所有模型提供商均请求失败，请稍后重试'
         });
       }
-      // If not last attempt and headers not sent, try next provider
-      if (res.headersSent) return;
+      // Otherwise continue to next provider
     }
   }
 }
diff --git a/src/brain/memory-manager.js b/src/brain/memory-manager.js
index ccafaeb8..3d2c4e17 100644
--- a/src/brain/memory-manager.js
+++ b/src/brain/memory-manager.js
@@ -55,8 +55,8 @@ function generateCandidates(text, source = 'user') {
       const end = Math.min(text.length, idx + 80);
       const excerpt = text.slice(start, end).replace(/\n/g, ' ').trim();
 
-      // 检查中期记忆中的出现次数
-      const memKey = type + ':' + excerpt.slice(0, 20);
+      // 检查中期记忆中的出现次数（使用类型+摘要前40字符作为键，降低碰撞风险）
+      const memKey = type + ':' + excerpt.slice(0, 40).replace(/\s+/g, '_');
       const taskEntry = taskMemory.get(memKey) || { count: 0 };
       taskEntry.count++;
       taskEntry.lastSeen = Date.now();
diff --git a/src/brain/model-router.js b/src/brain/model-router.js
index a6cb3557..f203d4a5 100644
--- a/src/brain/model-router.js
+++ b/src/brain/model-router.js
@@ -100,7 +100,7 @@ function isInCooldown(provider, model) {
     failureLog.delete(key);
     return false;
   }
-  return entry.count >= 3; // 5分钟内失败3次以上才冷却
+  return entry.count >= 3; // 5分钟内失败3次及以上才冷却
 }
 
 /**
diff --git a/src/schemas/hli/brain/prompt.schema.json b/src/schemas/hli/brain/prompt.schema.json
index 1a81c99f..c49c9e43 100644
--- a/src/schemas/hli/brain/prompt.schema.json
+++ b/src/schemas/hli/brain/prompt.schema.json
@@ -13,6 +13,7 @@
       "ghUser": { "type": "string", "description": "GitHub 用户名" },
       "role": { "type": "string", "enum": ["founder", "supreme", "main", "dev", "guest"] },
       "mode": { "type": "string", "enum": ["chat", "build", "review", "brain"] },
+      "text": { "type": "string", "description": "当前用户输入文本（用于自动检测模式）" },
       "devStatus": { "type": "object", "description": "开发者状态" }
     }
   },