feat: add MCP health check

backend/app/api/mcp.py

@@ -1,10 +1,15 @@
 import json
 import uuid
+import asyncio
 from typing import List, Optional
 from pathlib import Path
+from contextlib import AsyncExitStack
 
 from fastapi import APIRouter, HTTPException, Depends
 from pydantic import BaseModel
+from mcp import ClientSession, StdioServerParameters
+from mcp.client.stdio import stdio_client
+from mcp.client.sse import sse_client
 
 from app.schemas.mcp import MCPServer, MCPServerCreate, MCPServerUpdate
 from app.core.data_root import get_data_root
@@ -29,11 +34,59 @@ def write_mcp_servers(servers: List[dict]) -> None:
     with open(file_path, "w", encoding="utf-8") as f:
         json.dump(servers, f, indent=2, ensure_ascii=False)
 
+async def _check_single_mcp_health(server: dict) -> str:
+    try:
+        async with AsyncExitStack() as stack:
+            server_type = server.get("type")
+            if server_type == "stdio":
+                params = StdioServerParameters(
+                    command=server.get("command", ""),
+                    args=server.get("args", []),
+                    env=server.get("env")
+                )
+                read, write = await stack.enter_async_context(stdio_client(params))
+            elif server_type in ["sse", "streamableHttp"]:
+                read, write = await stack.enter_async_context(sse_client(server.get("url", "")))
+            else:
+                return "error: unsupported type"
+
+            session = await stack.enter_async_context(ClientSession(read, write))
+            await asyncio.wait_for(session.initialize(), timeout=5.0)
+            return "connected"
+    except Exception as e:
+        err_msg = str(e)
+        if "unhandled errors in a TaskGroup" in err_msg:
+            return "error: connection refused"
+        return f"error: {err_msg or 'unknown'}"
+
 @router.get("/mcp", response_model=List[MCPServer])
-def list_mcp_servers(project_id: Optional[int] = None):
+async def list_mcp_servers(project_id: Optional[int] = None):
     servers = read_mcp_servers()
     if project_id is not None:
         servers = [s for s in servers if s.get("project_id") == project_id]
+        
+    if not servers:
+        return []
+        
+    tasks = [_check_single_mcp_health(s) for s in servers]
+    statuses = await asyncio.gather(*tasks, return_exceptions=True)
+    
+    needs_update = False
+    for server, status in zip(servers, statuses):
+        new_status = status if isinstance(status, str) else f"error: {str(status)}"
+        if server.get("status") != new_status:
+            server["status"] = new_status
+            needs_update = True
+            
+    if needs_update:
+        # Write back to persist the new statuses
+        all_servers = read_mcp_servers()
+        for s in all_servers:
+            for checked_s in servers:
+                if s.get("id") == checked_s.get("id"):
+                    s["status"] = checked_s["status"]
+        write_mcp_servers(all_servers)
+        
     return servers
 
 @router.post("/mcp", response_model=MCPServer)