update

backend/api/chat_router.py

@@ -28,7 +28,7 @@ from core.llm_catalog import (
     validate_request_can_use_provider,
 )
 from core.database import get_db_pool, get_checkpointer, reset_db_pools_on_connection_error
-from core.mcp_client import get_mcp_client
+from core.mcp_client import load_mcp_tools_safe
 from core.dependencies import get_current_user, get_moderation_service
 from core.exceptions import ModerationError
 from models.user import User
@@ -771,9 +771,8 @@ async def _create_agent_for_request(
             checkpointer=checkpointer
         )
     
-    # 普通聊天模式
+    # 普通聊天模式（MCP 不可用时降级为无 MCP 工具，不阻断聊天）
-    mcp_client = await get_mcp_client()
+    mcp_tools = await load_mcp_tools_safe()
-    mcp_tools = await mcp_client.get_tools()
     mcp_tools = [_wrap_mcp_tool_safe(t) for t in mcp_tools]
     logger.info(f"成功加载 {len(mcp_tools)} 个 MCP 工具")
     

backend/core/mcp_client.py

@@ -6,6 +6,7 @@ MCP 客户端管理模块
 """
 from typing import Optional
 
+from langchain_core.tools import BaseTool
 from langchain_mcp_adapters.client import MultiServerMCPClient
 
 from core.config import settings
@@ -58,6 +59,44 @@ async def get_mcp_client() -> MultiServerMCPClient:
     return _mcp_client
 
 
+async def load_mcp_tools_safe() -> list[BaseTool]:
+    """
+    加载 MCP 工具；单个服务器连接/鉴权失败时跳过并继续，不阻断聊天。
+    """
+    if not is_mcp_enabled():
+        return []
+
+    client = await get_mcp_client()
+    if not client.connections:
+        return []
+
+    all_tools: list[BaseTool] = []
+    for server_name in client.connections:
+        conn = client.connections[server_name]
+        url = conn.get("url", "?")
+        try:
+            tools = await client.get_tools(server_name=server_name)
+            all_tools.extend(tools)
+            logger.info(
+                "MCP 服务器 {} ({}) 已加载 {} 个工具",
+                server_name,
+                url,
+                len(tools),
+            )
+        except Exception as exc:
+            logger.warning(
+                "MCP 服务器 {} ({}) 不可用，已跳过: {}",
+                server_name,
+                url,
+                exc,
+            )
+
+    if not all_tools and client.connections:
+        logger.warning("所有 MCP 服务器均不可用，聊天将继续但不提供 MCP 工具")
+
+    return all_tools
+
+
 async def close_mcp_client():
     """关闭 MCP 客户端"""
     global _mcp_client