Error initializing MCP server: Connection closed

[gns-pkulkarni]

I was trying to connect to openbnb MCP server from https://github.com/openbnb-org/mcp-server-airbnb. I'm new to both. While my filesystem MCP example works but this one doesn't

My versions are

• Python 3.12.3
• npx 10.9.2
• pip show openai-agentsis
  Name: openai-agents
  Version: 0.0.17
  Summary: OpenAI Agents SDK
  Home-page: https://github.com/openai/openai-agents-python
  Author:
  Author-email: OpenAI support@openai.com
  License-Expression: MIT
  Location: d:\cursor\openai_mcp.venv\Lib\site-packages
  Requires: griffe, mcp, openai, pydantic, requests, types-requests, typing-extensions
  Required-by:

Traceback

Error initializing MCP server: Connection closed
Traceback (most recent call last):
  File "D:\cursor\openai_mcp\mcp_openbnb_example.py", line 32, in <module>
    asyncio.run(main())
  File "C:\Users\GNS132\AppData\Local\Programs\Python\Python312\Lib\asyncio\runners.py", line 194, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "C:\Users\GNS132\AppData\Local\Programs\Python\Python312\Lib\asyncio\runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\GNS132\AppData\Local\Programs\Python\Python312\Lib\asyncio\base_events.py", line 687, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "D:\cursor\openai_mcp\mcp_openbnb_example.py", line 21, in main
    async with openbnb_server as openbnb:
  File "d:\cursor\openai_mcp\.venv\Lib\site-packages\agents\mcp\server.py", line 98, in __aenter__  
    await self.connect()
  File "d:\cursor\openai_mcp\.venv\Lib\site-packages\agents\mcp\server.py", line 126, in connect    
    server_result = await session.initialize()
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "d:\cursor\openai_mcp\.venv\Lib\site-packages\mcp\client\session.py", line 133, in initialize
    result = await self.send_request(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "d:\cursor\openai_mcp\.venv\Lib\site-packages\mcp\shared\session.py", line 297, in send_request
    raise McpError(response_or_error.error)
mcp.shared.exceptions.McpError: Connection closed

[Sucran]

@gns-pkulkarni
can you show your code? In agents sdk, MCPServer class has 'connect' and 'cleanup' methods which need to be aenter and aexit methods. It means you should wrap your mcp server in "async with..." code like:

async with MCPServerStdio(
        cache_tools_list=True,  # Cache the tools list, for demonstration
        params={"command": "uvx", "args": ["mcp-server-git"]},
    ) as server:
        with trace(workflow_name="MCP Git Example"):
            await run(server, directory_path) # Runner to run agents

or like

async with contextlib.AsyncExitStack() as stack:
    server = await stack.enter_async_context(MCPServerStreamableHttp(
                        name=name,
                        params=param,
                        cache_tools_list=True,
                        client_session_timeout_seconds=1800
                    ))

In "async with..." code phase, python will trigger aenter and aexit methods automatically.

I think if you reopen a mcp server without connect or already cleanup, you will see the exception like you showed