MCPO timeout every 10 seconds

[jwnalynsh]

Hello,

I have created an MCP server using Spring AI that uses the SSE (Server-Sent Events) transport protocol. When I access this MCP server via a different Web UI, everything works fine. However, when I access it through the MCPO proxy, the connection times out after 10 seconds.

I am running the MCPO proxy via Docker Compose with the following configuration:

  mcp-proxy:
    image: ghcr.io/open-webui/mcpo:main
    container_name: mcp-proxy
    restart: always
    command:
      - --server-type
      - "sse"
      - --
      - http://mcp:8080/sse
    ports:
      - "8000:8000"
    depends_on:
      - mcp

Below MCPO proxy logs showing the timeout error after about 10 seconds:

root@n8n:~/n8n-project# docker logs mcp-proxy -f
2025-08-08 13:37:42,573 - INFO - Starting MCPO Server...
2025-08-08 13:37:42,573 - INFO -   Name: MCP OpenAPI Proxy
2025-08-08 13:37:42,573 - INFO -   Version: 1.0
2025-08-08 13:37:42,573 - INFO -   Description: Automatically generated API from MCP Tool Schemas
2025-08-08 13:37:42,573 - INFO -   Hostname: 848bdbe5a816
2025-08-08 13:37:42,573 - INFO -   Port: 8000
2025-08-08 13:37:42,573 - INFO -   API Key: Not Provided
2025-08-08 13:37:42,573 - INFO -   CORS Allowed Origins: ['*']
2025-08-08 13:37:42,573 - INFO -   Path Prefix: /
2025-08-08 13:37:42,574 - INFO - Configuring for a single SSE MCP Server with URL http://mcp:8080/sse
2025-08-08 13:37:42,574 - INFO - Uvicorn server starting...
INFO:     Started server process [1]
INFO:     Waiting for application startup.
2025-08-08 13:37:43,047 - INFO - HTTP Request: GET http://mcp:8080/sse "HTTP/1.1 200 OK"
2025-08-08 13:37:43,157 - INFO - HTTP Request: POST http://mcp:8080/mcp/message?sessionId=3822c670-4bf3-406a-b567-683568c75f9e "HTTP/1.1 200 OK"
2025-08-08 13:37:43,171 - INFO - HTTP Request: POST http://mcp:8080/mcp/message?sessionId=3822c670-4bf3-406a-b567-683568c75f9e "HTTP/1.1 200 OK"
2025-08-08 13:37:43,200 - INFO - HTTP Request: POST http://mcp:8080/mcp/message?sessionId=3822c670-4bf3-406a-b567-683568c75f9e "HTTP/1.1 200 OK"
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
2025-08-08 13:37:53,198 - ERROR - Error in sse_reader
Traceback (most recent call last):
  File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 101, in map_httpcore_exceptions
    yield
  File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 271, in __aiter__
    async for part in self._httpcore_stream:
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/connection_pool.py", line 407, in __aiter__
    raise exc from None
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/connection_pool.py", line 403, in __aiter__
    async for part in self._stream:
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 342, in __aiter__
    raise exc
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 334, in __aiter__
    async for chunk in self._connection._receive_response_body(**kwargs):
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 203, in _receive_response_body
    event = await self._receive_event(timeout=timeout)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 217, in _receive_event
    data = await self._network_stream.read(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_backends/anyio.py", line 32, in read
    with map_exceptions(exc_map):
  File "/usr/lib/python3.11/contextlib.py", line 155, in __exit__
    self.gen.throw(typ, value, traceback)
  File "/app/.venv/lib/python3.11/site-packages/httpcore/_exceptions.py", line 14, in map_exceptions
    raise to_exc(exc) from exc
httpcore.ReadTimeout

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/app/.venv/lib/python3.11/site-packages/mcp/client/sse.py", line 72, in sse_reader
    async for sse in event_source.aiter_sse():
  File "/app/.venv/lib/python3.11/site-packages/httpx_sse/_api.py", line 42, in aiter_sse
    async for line in lines:
  File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 1031, in aiter_lines
    async for text in self.aiter_text():
  File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 1018, in aiter_text
    async for byte_content in self.aiter_bytes():
  File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 997, in aiter_bytes
    async for raw_bytes in self.aiter_raw():
  File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 1055, in aiter_raw
    async for raw_stream_bytes in self.stream:
  File "/app/.venv/lib/python3.11/site-packages/httpx/_client.py", line 176, in __aiter__
    async for chunk in self._stream:
  File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 270, in __aiter__
    with map_httpcore_exceptions():
  File "/usr/lib/python3.11/contextlib.py", line 155, in __exit__
    self.gen.throw(typ, value, traceback)
  File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 118, in map_httpcore_exceptions
    raise mapped_exc(message) from exc
httpx.ReadTimeout

[WSINTRA]

Line 446 in src/main of mcpo, what value do you see?