[Bug] `cforge run` not working

[gabe-l-hart]

Describe the bug

With the latest version of the upstream project, the cforge run command is no longer working.

Sample Code

# Terminal 1 (run the server)
rm tmp/*; CONTEXTFORGE_HOME=$PWD/tmp cforge serve --port 5555 --no-auth

# Terminal 2 (run and register mcp-server)
PORT=5555 CFORGE_HOME=$PWD/tmp cforge run --stdio "docker run -it --rm -e GITHUB_PERSONAL_ACCESS_TOKEN=$GITHUB_PUBLIC_READ_ONLY_TOKEN ghcr.io/github/github-mcp-server" --temporary --port 9005

Expected behavior

The MCP server should boot and auto-register itself with ContextForge, then unregister when quit.

Observed behavior

Registration fails with a 500 that I believe is coming from CF trying to invoke the MCP server:

error in cforge serve

2026-02-12T12:05:59 - mcp.client.sse - ERROR - Error in post_writer
Traceback (most recent call last):
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/mcp/client/sse.py", line 147, in post_writer
    response.raise_for_status()
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/httpx/_models.py", line 829, in raise_for_status
    raise HTTPStatusError(message, request=request, response=self)
httpx.HTTPStatusError: Server error '500 Internal Server Error' for url 'http://localhost:9005/message?session_id=9b94d60e421a4129855a767fc0b0fde4'
For more information check: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500

error in cforge run

logs

INFO:     127.0.0.1:49295 - "POST /message?session_id=9b94d60e421a4129855a767fc0b0fde4 HTTP/1.1" 500 Internal Server Error
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/uvicorn/protocols/http/httptools_impl.py", line 416, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/uvicorn/middleware/proxy_headers.py", line 60, in __call__
    return await self.app(scope, receive, send)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/applications.py", line 1135, in __call__
    await super().__call__(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/applications.py", line 107, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/middleware/errors.py", line 186, in __call__
    raise exc
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/middleware/errors.py", line 164, in __call__
    await self.app(scope, receive, _send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/middleware/exceptions.py", line 63, in __call__
    await wrap_app_handling_exceptions(self.app, conn)(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/routing.py", line 716, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/routing.py", line 736, in app
    await route.handle(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/routing.py", line 290, in handle
    await self.app(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/routing.py", line 115, in app
    await wrap_app_handling_exceptions(app, request)(scope, receive, send)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/_exception_handler.py", line 53, in wrapped_app
    raise exc
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/routing.py", line 101, in app
    response = await f(request)
               ^^^^^^^^^^^^^^^^
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/routing.py", line 355, in app
    raw_response = await run_endpoint_function(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/fastapi/routing.py", line 243, in run_endpoint_function
    return await dependant.call(**values)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/mcpgateway/translate.py", line 1960, in post_message
    await stdio.send(payload.decode().rstrip() + "\n")
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/site-packages/mcpgateway/translate.py", line 521, in send
    await self._stdin.drain()
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/asyncio/streams.py", line 392, in drain
    await self._protocol._drain_helper()
  File "/Users/ghart/miniforge3/envs/contextforge-cli/lib/python3.11/asyncio/streams.py", line 166, in _drain_helper
    raise ConnectionResetError('Connection lost')
ConnectionResetError: Connection lost

[gabe-l-hart]

Ok, this appears to actually be a problem with the MCP server I was using. It's working fine using the sample time server:

PORT=5555 CFORGE_HOME=$PWD/tmp cforge run --stdio "docker run --rm -i ghcr.io/ibm/fast-time-server:latest -transport=stdio" --temporary --port 9005