在开发 MCP Client 的过程中，发生了 -32000 报错，源码如下：

import json
from typing import Optional
from contextlib import AsyncExitStackfrom openai import OpenAIfrom mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_clientclass MCPClient:def __init__(self):""" 初始化 MCP 客户端 """self.exit_stack = AsyncExitStack()self.openai_api_key = "sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxx", # 替换成自己的 API_KEYself.base_url = "https://dashscope.aliyuncs.com/compatible-mode/v1"self.model = "qwen-turbo"self.client = OpenAI(api_key=self.openai_api_key, base_url=self.base_url) # 创建OpenAI clientself.session: Optional[ClientSession] = Noneself.exit_stack = AsyncExitStack()        async def connect_to_server(self, server_script_path: str):""" 连接到 MCP 服务器Args:服务脚本的文件路径: Path to the server script (.py or .js)"""is_python = server_script_path.endswith('.py')is_js = server_script_path.endswith('.js')if not (is_python or is_js):raise ValueError("Server script must be a .py or .js file")command = "python" if is_python else "node"server_params = StdioServerParameters(command = command,args = [server_script_path],env = None)# 启动 MCP 服务器并建立通信stdio_transport = await self.exit_stack.enter_async_context(stdio_client(server_params))self.stdio, self.write = stdio_transportself.session = await self.exit_stack.enter_async_context(ClientSession(self.stdio, self.write))await self.session.initialize()# 列出 MCP 服务器上的工具response = await self.session.list_tools()tools = response.toolsprint("\nConnected to server with tools:", [tool.name for tool in tools])     async def process_query(self, query: str) -> str:"""使用大模型处理查询并调用可用的 MCP 工具 (Function Calling)"""messages = [{"role": "user", "content": query}]response = await self.session.list_tools()available_tools = [{"type": "function","function": {"name": tool.name,"description": tool.description,"parameters":  tool.inputSchema}} for tool in response.tools]# print(available_tools)response = self.client.chat.completions.create(model=self.model,            messages=messages,tools=available_tools     )content = response.choices[0]if content.finish_reason == "tool_calls":# 如何是需要使用工具，就解析工具tool_call = content.message.tool_calls[0]tool_name = tool_call.function.nametool_args = json.loads(tool_call.function.arguments)# 执行工具result = await self.session.call_tool(tool_name, tool_args)print(f"\n\n[Calling tool {tool_name} with args {tool_args}]\n\n")# 将模型返回的调用哪个工具数据和工具执行完成后的数据都存入messages中messages.append(content.message.model_dump())messages.append({"role": "tool","content": result.content[0].text,"tool_call_id": tool_call.id,})# 将上面的结果再返回给大模型用于生产最终的结果response = self.client.chat.completions.create(model=self.model,messages=messages,)return response.choices[0].message.contentreturn content.message.contentasync def chat_loop(self):"""运行交互式聊天循环"""print("\n🤖 MCP 客户端已启动！输入 'quit' 退出")while True:try:query = input("\n你: ").strip()if query.lower() == 'quit':breakresponse = await self.process_query(query)  # 发送用户输入到 OpenAI APIprint(f"\n🤖 OpenAI: {response}")except Exception as e:print(f"\n⚠️ 发生错误: {str(e)}")async def cleanup(self):"""清理资源"""await self.exit_stack.aclose()async def main():client = MCPClient()try:# 下面的路径替换成自己的 mcp server 脚本的路径await client.connect_to_server(r"C:\Users\User\Desktop\mcp\mcp_server.py")await client.chat_loop()finally:await client.cleanup()if __name__ == "__main__":import asyncioasyncio.run(main())

上面红框出发生如下报错：

Traceback (most recent call last):
 line 46, in connect_to_server
    await self.session.initialize()
  File "C:\ProgramData\anaconda3\Lib\site-packages\mcp\client\session.py", line 123, in initialize
    result = await self.send_request(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\ProgramData\anaconda3\Lib\site-packages\mcp\shared\session.py", line 286, in send_request
    raise McpError(response_or_error.error)
mcp.shared.exceptions.McpError: Connection closed

经过调试后打印出如下日志：

Received response for request 0: jsonrpc='2.0' id=0 error=ErrorData(code=-32000, message='Connection closed', data=None)

最后解决结果：

这个报错一般是初始化 mcp server 出现了问题，首先 mcp_server.py 的脚本路径一定要正确，然后 mcp_server.py  脚本要能够独立运行，博主的报错原因是 在 mcp_server.py 中引入本地自己开发的包，但是没有在 sys.path 中加入该包的搜索路径，使得 mcp_server.py 无法运行，最终导致上面图中的报错。