fix: improve MCP compatibility with persistent sessions and server callbacks

docs/mcp-tool-config-guide.md

@@ -15,6 +15,7 @@
 2. 系统通过 `tools/list` 拉取远端工具
 3. 本地自动生成工具别名：`mcp__<server_id>__<tool_name>`
 4. 模型调用该别名时，桥接层转发到对应服务的 `tools/call`
+5. 对于同一服务，桥接层会复用长连接会话（避免每次调用都重启 MCP 进程），并处理常见 Server→Client 请求（如 `ping`、`roots/list`）
 
 内置了一个原生工具：
 

modules/mcp_client_manager.py

@@ -8,10 +8,11 @@ import os
 import select
 import shutil
 import subprocess
+import threading
 import time
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Any, Dict, Iterable, List, Optional, Tuple, TYPE_CHECKING
+from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple, TYPE_CHECKING
 
 import httpx
 
@@ -36,6 +37,18 @@ class MCPToolBinding:
     timeout_seconds: int
 
 
+@dataclass
+class MCPClientPoolEntry:
+    """长连接 MCP 客户端池条目。"""
+
+    server_id: str
+    signature: str
+    client: Any
+    timeout_seconds: int
+    created_at: float
+    last_used_at: float
+
+
 class _StdioMCPClient:
     """最小可用 stdio MCP 客户端（JSON-RPC over newline-delimited JSON）。"""
 
@@ -75,6 +88,9 @@ class _StdioMCPClient:
         self.container_session = container_session
         self.process: Optional[subprocess.Popen] = None
         self._seq = 0
+        self._initialized = False
+        self._initialize_result: Dict[str, Any] = {}
+        self._negotiated_protocol_version: Optional[str] = None
 
     def _next_id(self) -> int:
         self._seq += 1
@@ -248,6 +264,8 @@ class _StdioMCPClient:
         return cmd, None, dict(os.environ)
 
     def start(self) -> None:
+        if self.process and self.process.poll() is None:
+            return
         launch_cmd, cwd, env = self._prepare_launch()
         try:
             self.process = subprocess.Popen(
@@ -262,6 +280,9 @@ class _StdioMCPClient:
             )
         except Exception as exc:
             raise MCPClientError(f"启动 stdio MCP 服务失败: {exc}") from exc
+        self._initialized = False
+        self._initialize_result = {}
+        self._negotiated_protocol_version = None
 
     def _send(self, payload: Dict[str, Any]) -> None:
         if not self.process or not self.process.stdin:
@@ -316,41 +337,101 @@ class _StdioMCPClient:
                 last_text_line = line
                 continue
 
+    @staticmethod
+    def _build_server_request_result(method: str, params: Dict[str, Any]) -> Tuple[bool, Dict[str, Any]]:
+        """处理服务端发起的请求（Server -> Client Request）。"""
+        name = str(method or "").strip()
+        if name == "ping":
+            return True, {}
+        if name == "roots/list":
+            return True, {"roots": []}
+        if name == "completion/complete":
+            return False, {"code": -32601, "message": "completion/complete not supported by client"}
+        if name == "sampling/createMessage":
+            return False, {"code": -32601, "message": "sampling not supported by client"}
+        if name == "elicitation/create":
+            return False, {"code": -32601, "message": "elicitation not supported by client"}
+        return False, {"code": -32601, "message": f"Client method not implemented: {name}"}
+
+    @staticmethod
+    def _handle_server_notification(method: str, params: Dict[str, Any]) -> None:
+        """处理服务端通知（Server -> Client Notification）。当前策略：静默接收。"""
+        _ = method, params
+
+    def _respond_server_request(self, msg: Dict[str, Any]) -> None:
+        msg_id = msg.get("id")
+        method = str(msg.get("method") or "").strip()
+        params = msg.get("params")
+        if not isinstance(params, dict):
+            params = {}
+        try:
+            ok, payload = self._build_server_request_result(method, params)
+            if ok:
+                self._send({"jsonrpc": "2.0", "id": msg_id, "result": payload})
+            else:
+                self._send({"jsonrpc": "2.0", "id": msg_id, "error": payload})
+        except Exception as exc:
+            self._send(
+                {
+                    "jsonrpc": "2.0",
+                    "id": msg_id,
+                    "error": {"code": -32603, "message": f"Client internal error: {exc}"},
+                }
+            )
+
     def request(self, method: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        if not self.process or self.process.poll() is not None:
+            self.start()
         req_id = self._next_id()
         payload = {"jsonrpc": "2.0", "id": req_id, "method": method, "params": params or {}}
         self._send(payload)
         while True:
             msg = self._read_message()
-            if msg.get("id") == req_id:
+
+            # 收到目标响应
+            if msg.get("id") == req_id and "method" not in msg:
                 if "error" in msg:
                     error = msg.get("error") or {}
                     raise MCPClientError(f"{method} 调用失败: {error}")
                 return msg.get("result") or {}
-            # 服务器主动向客户端发起请求时，返回 method not found，避免阻塞
+
+            # 服务端请求：回包后继续等待目标响应
             if "id" in msg and "method" in msg:
-                self._send(
-                    {
-                        "jsonrpc": "2.0",
-                        "id": msg.get("id"),
-                        "error": {"code": -32601, "message": "Client method not implemented"},
-                    }
-                )
+                self._respond_server_request(msg)
+                continue
+
+            # 服务端通知：消费后继续
+            if "method" in msg:
+                self._handle_server_notification(str(msg.get("method") or ""), msg.get("params") or {})
+                continue
 
     def notify(self, method: str, params: Optional[Dict[str, Any]] = None) -> None:
+        if not self.process or self.process.poll() is not None:
+            self.start()
         self._send({"jsonrpc": "2.0", "method": method, "params": params or {}})
 
     def initialize(self) -> Dict[str, Any]:
+        if self._initialized:
+            return dict(self._initialize_result)
+        if not self.process or self.process.poll() is not None:
+            self.start()
         result = self.request(
             "initialize",
             {
                 "protocolVersion": self.protocol_version,
-                "capabilities": {},
+                "capabilities": {
+                    "roots": {"listChanged": False},
+                },
                 "clientInfo": {"name": "agents-mcp-bridge", "version": "1.0.0"},
             },
         )
         self.notify("notifications/initialized")
-        return result
+        self._initialize_result = dict(result or {})
+        self._initialized = True
+        negotiated = result.get("protocolVersion") if isinstance(result, dict) else None
+        if negotiated:
+            self._negotiated_protocol_version = str(negotiated)
+        return dict(self._initialize_result)
 
     def close(self) -> None:
         if not self.process:
@@ -381,6 +462,9 @@ class _StdioMCPClient:
             except Exception:
                 pass
             self.process = None
+            self._initialized = False
+            self._initialize_result = {}
+            self._negotiated_protocol_version = None
 
 
 class _StreamableHTTPMCPClient:
@@ -394,6 +478,9 @@ class _StreamableHTTPMCPClient:
         self._session_id: Optional[str] = None
         self._seq = 0
         self._client = httpx.Client(timeout=self.timeout_seconds)
+        self._initialized = False
+        self._initialize_result: Dict[str, Any] = {}
+        self._negotiated_protocol_version: Optional[str] = None
 
     def _next_id(self) -> int:
         self._seq += 1
@@ -406,14 +493,35 @@ class _StreamableHTTPMCPClient:
                 return hv
         return None
 
-    def _build_headers(self) -> Dict[str, str]:
+    @staticmethod
+    def _infer_mcp_name(method: str, params: Optional[Dict[str, Any]]) -> Optional[str]:
+        if not isinstance(params, dict):
+            params = {}
+        method = str(method or "").strip()
+        if method == "tools/call":
+            value = params.get("name")
+            return str(value).strip() if value is not None else None
+        if method == "resources/read":
+            value = params.get("uri")
+            return str(value).strip() if value is not None else None
+        if method == "prompts/get":
+            value = params.get("name")
+            return str(value).strip() if value is not None else None
+        return None
+
+    def _build_headers(self, *, method: Optional[str] = None, params: Optional[Dict[str, Any]] = None) -> Dict[str, str]:
         headers = {
             "Accept": "application/json, text/event-stream",
             "Content-Type": "application/json",
-            "MCP-Protocol-Version": self.protocol_version,
+            "MCP-Protocol-Version": self._negotiated_protocol_version or self.protocol_version,
         }
         if self._session_id:
             headers["Mcp-Session-Id"] = self._session_id
+        if method:
+            headers["Mcp-Method"] = str(method)
+            name = self._infer_mcp_name(str(method), params)
+            if name:
+                headers["Mcp-Name"] = name
         headers.update(self.server.get("headers") or {})
         return headers
 
@@ -439,7 +547,62 @@ class _StreamableHTTPMCPClient:
                 events.append(parsed)
         return events
 
-    def _request(self, method: str, params: Optional[Dict[str, Any]] = None, notification: bool = False) -> Dict[str, Any]:
+    @staticmethod
+    def _build_server_request_result(method: str, params: Dict[str, Any]) -> Tuple[bool, Dict[str, Any]]:
+        name = str(method or "").strip()
+        if name == "ping":
+            return True, {}
+        if name == "roots/list":
+            return True, {"roots": []}
+        if name == "completion/complete":
+            return False, {"code": -32601, "message": "completion/complete not supported by client"}
+        if name == "sampling/createMessage":
+            return False, {"code": -32601, "message": "sampling not supported by client"}
+        if name == "elicitation/create":
+            return False, {"code": -32601, "message": "elicitation not supported by client"}
+        return False, {"code": -32601, "message": f"Client method not implemented: {name}"}
+
+    def _post_jsonrpc_message(self, payload: Dict[str, Any]) -> None:
+        try:
+            resp = self._client.post(
+                self.url,
+                headers=self._build_headers(),
+                json=payload,
+            )
+        except Exception as exc:
+            raise MCPClientError(f"HTTP MCP 回写失败: {exc}") from exc
+        if resp.status_code >= 400:
+            raise MCPClientError(f"HTTP MCP 回写状态异常: {resp.status_code} {resp.text[:400]}")
+
+    def _handle_server_request_message(self, message: Dict[str, Any]) -> None:
+        msg_id = message.get("id")
+        method = str(message.get("method") or "").strip()
+        params = message.get("params")
+        if not isinstance(params, dict):
+            params = {}
+        try:
+            ok, payload = self._build_server_request_result(method, params)
+            if ok:
+                self._post_jsonrpc_message({"jsonrpc": "2.0", "id": msg_id, "result": payload})
+            else:
+                self._post_jsonrpc_message({"jsonrpc": "2.0", "id": msg_id, "error": payload})
+        except Exception as exc:
+            self._post_jsonrpc_message(
+                {
+                    "jsonrpc": "2.0",
+                    "id": msg_id,
+                    "error": {"code": -32603, "message": f"Client internal error: {exc}"},
+                }
+            )
+
+    def _request(
+        self,
+        method: str,
+        params: Optional[Dict[str, Any]] = None,
+        notification: bool = False,
+        *,
+        _allow_session_retry: bool = True,
+    ) -> Dict[str, Any]:
         if not self.url:
             raise MCPClientError("streamable_http 服务缺少 url")
         req_id = None if notification else self._next_id()
@@ -447,7 +610,11 @@ class _StreamableHTTPMCPClient:
         if req_id is not None:
             payload["id"] = req_id
         try:
-            resp = self._client.post(self.url, headers=self._build_headers(), json=payload)
+            resp = self._client.post(
+                self.url,
+                headers=self._build_headers(method=method, params=params or {}),
+                json=payload,
+            )
         except Exception as exc:
             raise MCPClientError(f"HTTP MCP 请求失败: {exc}") from exc
 
@@ -455,6 +622,25 @@ class _StreamableHTTPMCPClient:
         if session_id:
             self._session_id = session_id
 
+        # 会话失效（服务端返回 404）时，按规范重新建立 session 并重试一次
+        if (
+            resp.status_code == 404
+            and self._session_id
+            and method != "initialize"
+            and _allow_session_retry
+        ):
+            self._session_id = None
+            self._initialized = False
+            self._initialize_result = {}
+            self._negotiated_protocol_version = None
+            self.initialize()
+            return self._request(
+                method,
+                params,
+                notification=notification,
+                _allow_session_retry=False,
+            )
+
         if resp.status_code >= 400:
             raise MCPClientError(f"HTTP MCP 状态异常: {resp.status_code} {resp.text[:400]}")
 
@@ -469,6 +655,13 @@ class _StreamableHTTPMCPClient:
                 message = parsed
         elif "text/event-stream" in content_type:
             for event in self._parse_sse_json_events(resp.text):
+                if not isinstance(event, dict):
+                    continue
+                if "method" in event:
+                    if "id" in event:
+                        self._handle_server_request_message(event)
+                    # 通知直接消费
+                    continue
                 if event.get("id") == req_id:
                     message = event
                     break
@@ -487,16 +680,25 @@ class _StreamableHTTPMCPClient:
         return message.get("result") or {}
 
     def initialize(self) -> Dict[str, Any]:
+        if self._initialized:
+            return dict(self._initialize_result)
         result = self._request(
             "initialize",
             {
                 "protocolVersion": self.protocol_version,
-                "capabilities": {},
+                "capabilities": {
+                    "roots": {"listChanged": False},
+                },
                 "clientInfo": {"name": "agents-mcp-bridge", "version": "1.0.0"},
             },
         )
         self._request("notifications/initialized", {}, notification=True)
-        return result
+        self._initialize_result = dict(result or {})
+        self._initialized = True
+        negotiated = result.get("protocolVersion") if isinstance(result, dict) else None
+        if negotiated:
+            self._negotiated_protocol_version = str(negotiated)
+        return dict(self._initialize_result)
 
     def request(self, method: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
         return self._request(method, params, notification=False)
@@ -511,6 +713,10 @@ class _StreamableHTTPMCPClient:
             self._client.close()
         except Exception:
             pass
+        self._session_id = None
+        self._initialized = False
+        self._initialize_result = {}
+        self._negotiated_protocol_version = None
 
 
 class MCPClientManager:
@@ -526,10 +732,141 @@ class MCPClientManager:
         self.protocol_version = str(protocol_version or MCP_PROTOCOL_VERSION)
         self.container_session = container_session
         self._latest_alias_map: Dict[str, MCPToolBinding] = {}
+        self._client_pool: Dict[str, MCPClientPoolEntry] = {}
+        self._pool_lock = threading.RLock()
+
+    def __del__(self):
+        try:
+            self.close_all_clients()
+        except Exception:
+            pass
 
     def set_container_session(self, session: Optional["ContainerHandle"]) -> None:
+        if session is self.container_session:
+            return
+        self.close_all_clients()
         self.container_session = session
 
+    @staticmethod
+    def _server_signature(server: Dict[str, Any]) -> str:
+        payload = {
+            "id": server.get("id"),
+            "transport": server.get("transport"),
+            "command": server.get("command"),
+            "args": server.get("args") or [],
+            "cwd": server.get("cwd"),
+            "env": server.get("env") or {},
+            "url": server.get("url"),
+            "headers": server.get("headers") or {},
+            "timeout_seconds": server.get("timeout_seconds"),
+        }
+        raw = json.dumps(payload, ensure_ascii=False, sort_keys=True)
+        return hashlib.sha1(raw.encode("utf-8")).hexdigest()
+
+    @staticmethod
+    def _is_client_alive(client: Any) -> bool:
+        process = getattr(client, "process", None)
+        if process is not None:
+            return bool(process.poll() is None)
+        # HTTP 客户端无法直接探活，按可用处理，失败时走重连兜底
+        return True
+
+    @staticmethod
+    def _safe_close_client(client: Any) -> None:
+        try:
+            if client:
+                client.close()
+        except Exception:
+            pass
+
+    def _close_pool_entry_locked(self, server_id: str) -> None:
+        entry = self._client_pool.pop(server_id, None)
+        if entry:
+            self._safe_close_client(entry.client)
+
+    def _ensure_client_locked(self, server: Dict[str, Any], timeout_seconds: int, *, force_recreate: bool = False):
+        sid = str(server.get("id") or "").strip()
+        if not sid:
+            raise MCPClientError("MCP 服务缺少 id")
+        signature = self._server_signature(server)
+        entry = self._client_pool.get(sid)
+        needs_recreate = force_recreate or (entry is None)
+        if entry and not needs_recreate:
+            if entry.signature != signature:
+                needs_recreate = True
+            elif not self._is_client_alive(entry.client):
+                needs_recreate = True
+
+        if needs_recreate:
+            if entry:
+                self._safe_close_client(entry.client)
+            client = self._make_client(server, timeout_seconds)
+            if hasattr(client, "start"):
+                client.start()
+            init_result = client.initialize()
+            now = time.time()
+            entry = MCPClientPoolEntry(
+                server_id=sid,
+                signature=signature,
+                client=client,
+                timeout_seconds=timeout_seconds,
+                created_at=now,
+                last_used_at=now,
+            )
+            self._client_pool[sid] = entry
+            return client, init_result
+
+        # 复用连接：动态刷新超时，并确保处于 initialized 状态
+        entry.timeout_seconds = timeout_seconds
+        try:
+            if hasattr(entry.client, "timeout_seconds"):
+                entry.client.timeout_seconds = max(3, int(timeout_seconds))
+            if hasattr(entry.client, "_client"):
+                entry.client._client.timeout = httpx.Timeout(max(3, int(timeout_seconds)))
+        except Exception:
+            pass
+        init_result = {}
+        if hasattr(entry.client, "initialize"):
+            init_result = entry.client.initialize() or {}
+        entry.last_used_at = time.time()
+        return entry.client, init_result
+
+    def _run_with_client(
+        self,
+        server: Dict[str, Any],
+        timeout_seconds: int,
+        operation: Callable[[Any], Any],
+    ) -> Tuple[Any, Dict[str, Any]]:
+        last_exc: Optional[Exception] = None
+        for attempt in range(2):
+            with self._pool_lock:
+                client, init_result = self._ensure_client_locked(
+                    server,
+                    timeout_seconds,
+                    force_recreate=attempt > 0,
+                )
+                sid = str(server.get("id") or "").strip()
+                try:
+                    output = operation(client)
+                    entry = self._client_pool.get(sid)
+                    if entry:
+                        entry.last_used_at = time.time()
+                    return output, init_result
+                except Exception as exc:  # pragma: no cover - 仅异常链路
+                    last_exc = exc
+                    self._close_pool_entry_locked(sid)
+                    continue
+        if last_exc:
+            raise last_exc
+        raise MCPClientError("MCP 客户端执行失败")
+
+    def close_all_clients(self) -> None:
+        with self._pool_lock:
+            entries = list(self._client_pool.values())
+            self._client_pool.clear()
+        for entry in entries:
+            self._safe_close_client(entry.client)
+
     @staticmethod
     def _sanitize_input_schema(schema: Any) -> Dict[str, Any]:
         if not isinstance(schema, dict):
@@ -625,12 +962,12 @@ class MCPClientManager:
             return {"success": False, "error": f"未找到 MCP 服务: {server_id}"}
         timeout = int(timeout_seconds or server.get("timeout_seconds") or MCP_DEFAULT_TIMEOUT_SECONDS)
         started = time.time()
-        client = None
         try:
-            client = self._make_client(server, timeout)
-            client.start() if hasattr(client, "start") else None
-            init_result = client.initialize()
-            tools = self._paged_list_tools(client)
+            tools, init_result = self._run_with_client(
+                server,
+                timeout,
+                lambda client: self._paged_list_tools(client),
+            )
             self.registry.update_tools_cache(server_id, tools=tools, error="", touched=True)
             elapsed_ms = int((time.time() - started) * 1000)
             return {
@@ -644,17 +981,20 @@ class MCPClientManager:
         except Exception as exc:
             self.registry.update_tools_cache(server_id, error=str(exc), touched=True)
             return {"success": False, "server_id": server_id, "error": str(exc)}
-        finally:
-            try:
-                if client:
-                    client.close()
-            except Exception:
-                pass
 
     def sync_servers(self, server_id: Optional[str] = None) -> Dict[str, Any]:
         # 先从磁盘重载一次，避免「文件已改但进程内缓存未刷新」导致同步遗漏，
         # 以及后续 update_tools_cache 把旧缓存反写覆盖新配置。
         self.registry.reload()
+        with self._pool_lock:
+            enabled_ids = {
+                str(item.get("id") or "").strip()
+                for item in self.registry.list_enabled_servers()
+                if str(item.get("id") or "").strip()
+            }
+            stale_ids = [sid for sid in list(self._client_pool.keys()) if sid not in enabled_ids]
+            for sid in stale_ids:
+                self._close_pool_entry_locked(sid)
         if server_id:
             return self.discover_tools_for_server(server_id)
         results = []
@@ -775,15 +1115,15 @@ class MCPClientManager:
             return {"success": False, "error": f"MCP 服务已禁用: {binding.server_id}"}
 
         timeout = int(server.get("timeout_seconds") or binding.timeout_seconds or MCP_DEFAULT_TIMEOUT_SECONDS)
-        client = None
         started = time.time()
         try:
-            client = self._make_client(server, timeout)
-            client.start() if hasattr(client, "start") else None
-            client.initialize()
-            call_result = client.request(
+            call_result, _ = self._run_with_client(
+                server,
+                timeout,
+                lambda client: client.request(
                     "tools/call",
                     {"name": binding.remote_name, "arguments": arguments or {}},
+                ),
             )
             is_error = bool((call_result or {}).get("isError"))
             content_items = (call_result or {}).get("content") or []
@@ -816,9 +1156,3 @@ class MCPClientManager:
                 "transport": binding.transport,
                 "error": str(exc),
             }
-        finally:
-            try:
-                if client:
-                    client.close()
-            except Exception:
-                pass

test/test_mcp_integration.py

@@ -4,6 +4,7 @@ import asyncio
 import json
 import sys
 import tempfile
+import textwrap
 import unittest
 from pathlib import Path
 from types import SimpleNamespace
@@ -42,7 +43,16 @@ class MCPIntegrationTest(unittest.TestCase):
             }
         )
 
+    def _write_temp_server(self, filename: str, content: str) -> Path:
+        path = self.project_dir / filename
+        path.write_text(textwrap.dedent(content).strip() + "\n", encoding="utf-8")
+        return path
+
     def tearDown(self):
+        try:
+            self.manager.close_all_clients()
+        except Exception:
+            pass
         self.temp_dir.cleanup()
 
     def test_manager_discover_and_call(self):
@@ -252,6 +262,248 @@ class MCPIntegrationTest(unittest.TestCase):
         self.assertNotIn("/opt/homebrew/bin/npx", launch_cmd)
         self.assertIn("/Users/jojo/Desktop", launch_cmd)
 
+    def test_stateful_stdio_server_reuses_persistent_session(self):
+        stateful_script = self._write_temp_server(
+            "stateful_mcp_server.py",
+            """
+            import json
+            import sys
+
+            counter = 0
+
+            def send(payload):
+                sys.stdout.write(json.dumps(payload, ensure_ascii=False) + "\\n")
+                sys.stdout.flush()
+
+            while True:
+                line = sys.stdin.readline()
+                if not line:
+                    break
+                line = line.strip()
+                if not line:
+                    continue
+                req = json.loads(line)
+                method = req.get("method")
+                msg_id = req.get("id")
+                params = req.get("params") or {}
+                if msg_id is None:
+                    continue
+                if method == "initialize":
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "protocolVersion": "2025-06-18",
+                            "capabilities": {"tools": {}},
+                            "serverInfo": {"name": "stateful", "version": "1.0.0"},
+                        },
+                    })
+                    continue
+                if method == "tools/list":
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "tools": [
+                                {
+                                    "name": "next_counter",
+                                    "description": "返回递增计数器",
+                                    "inputSchema": {"type": "object", "properties": {}},
+                                }
+                            ]
+                        },
+                    })
+                    continue
+                if method == "tools/call":
+                    name = str(params.get("name") or "")
+                    if name == "next_counter":
+                        counter += 1
+                        send({
+                            "jsonrpc": "2.0",
+                            "id": msg_id,
+                            "result": {
+                                "isError": False,
+                                "content": [{"type": "text", "text": str(counter)}],
+                                "structuredContent": {"counter": counter},
+                            },
+                        })
+                        continue
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "isError": True,
+                            "content": [{"type": "text", "text": "unknown tool"}],
+                        },
+                    })
+                    continue
+                send({
+                    "jsonrpc": "2.0",
+                    "id": msg_id,
+                    "error": {"code": -32601, "message": f"Method not found: {method}"},
+                })
+            """,
+        )
+        self.registry.upsert_server(
+            {
+                "id": "stateful_stdio",
+                "name": "Stateful MCP",
+                "transport": "stdio",
+                "enabled": True,
+                "command": sys.executable,
+                "args": [str(stateful_script)],
+                "timeout_seconds": 10,
+            }
+        )
+
+        sync_result = self.manager.sync_servers(server_id="stateful_stdio")
+        self.assertTrue(sync_result.get("success"), sync_result)
+
+        _, alias_map = self.manager.build_openai_tools(ensure_discovery=False)
+        alias = None
+        for key, binding in alias_map.items():
+            if binding.server_id == "stateful_stdio" and binding.remote_name == "next_counter":
+                alias = key
+                break
+        self.assertTrue(alias, f"missing alias for stateful server: {list(alias_map.keys())}")
+
+        first = self.manager.call_tool_by_alias(alias, {}, alias_map=alias_map)
+        second = self.manager.call_tool_by_alias(alias, {}, alias_map=alias_map)
+
+        self.assertTrue(first.get("success"), first)
+        self.assertTrue(second.get("success"), second)
+        self.assertEqual((first.get("structured_content") or {}).get("counter"), 1, first)
+        self.assertEqual((second.get("structured_content") or {}).get("counter"), 2, second)
+
+    def test_stdio_server_request_ping_is_handled(self):
+        ping_script = self._write_temp_server(
+            "ping_request_mcp_server.py",
+            """
+            import json
+            import select
+            import sys
+            import time
+
+            def send(payload):
+                sys.stdout.write(json.dumps(payload, ensure_ascii=False) + "\\n")
+                sys.stdout.flush()
+
+            def read_json_line(timeout_seconds):
+                deadline = time.monotonic() + timeout_seconds
+                while time.monotonic() < deadline:
+                    remain = max(0.05, deadline - time.monotonic())
+                    readable, _, _ = select.select([sys.stdin], [], [], min(0.2, remain))
+                    if not readable:
+                        continue
+                    line = sys.stdin.readline()
+                    if not line:
+                        return None
+                    line = line.strip()
+                    if not line:
+                        continue
+                    try:
+                        return json.loads(line)
+                    except Exception:
+                        continue
+                return None
+
+            while True:
+                line = sys.stdin.readline()
+                if not line:
+                    break
+                line = line.strip()
+                if not line:
+                    continue
+                req = json.loads(line)
+                method = req.get("method")
+                msg_id = req.get("id")
+                params = req.get("params") or {}
+                if msg_id is None:
+                    continue
+                if method == "initialize":
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "protocolVersion": "2025-06-18",
+                            "capabilities": {"tools": {}},
+                            "serverInfo": {"name": "ping-stdio", "version": "1.0.0"},
+                        },
+                    })
+                    continue
+                if method == "tools/list":
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "tools": [
+                                {
+                                    "name": "trigger_ping",
+                                    "description": "触发服务端 ping 请求",
+                                    "inputSchema": {"type": "object", "properties": {}},
+                                }
+                            ]
+                        },
+                    })
+                    continue
+                if method == "tools/call":
+                    ping_id = 9001
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": ping_id,
+                        "method": "ping",
+                        "params": {},
+                    })
+                    response = read_json_line(2.5) or {}
+                    ok = (
+                        isinstance(response, dict)
+                        and response.get("id") == ping_id
+                        and isinstance(response.get("result"), dict)
+                    )
+                    send({
+                        "jsonrpc": "2.0",
+                        "id": msg_id,
+                        "result": {
+                            "isError": not ok,
+                            "content": [{"type": "text", "text": "ping_ok" if ok else "ping_failed"}],
+                            "structuredContent": {"ping_ok": ok},
+                        },
+                    })
+                    continue
+                send({
+                    "jsonrpc": "2.0",
+                    "id": msg_id,
+                    "error": {"code": -32601, "message": f"Method not found: {method}"},
+                })
+            """,
+        )
+        self.registry.upsert_server(
+            {
+                "id": "ping_stdio",
+                "name": "Ping MCP",
+                "transport": "stdio",
+                "enabled": True,
+                "command": sys.executable,
+                "args": [str(ping_script)],
+                "timeout_seconds": 10,
+            }
+        )
+
+        sync_result = self.manager.sync_servers(server_id="ping_stdio")
+        self.assertTrue(sync_result.get("success"), sync_result)
+
+        _, alias_map = self.manager.build_openai_tools(ensure_discovery=False)
+        alias = None
+        for key, binding in alias_map.items():
+            if binding.server_id == "ping_stdio" and binding.remote_name == "trigger_ping":
+                alias = key
+                break
+        self.assertTrue(alias, f"missing alias for ping server: {list(alias_map.keys())}")
+
+        result = self.manager.call_tool_by_alias(alias, {}, alias_map=alias_map)
+        self.assertTrue(result.get("success"), result)
+        self.assertTrue((result.get("structured_content") or {}).get("ping_ok"), result)
+
 
 if __name__ == "__main__":
     unittest.main()