Do MCP SSE URLs from <http://pipedream.com|pipedream.com> Work with Crewai, Autogen, and Others?

user-1 · April 17, 2025, 8:54pm

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are the mcp sse urls generated using mcp.pipedream.com, works with crewai, autogen etc? i’ve tried the zapier mcp and an mcp endpoint generated using pipedream - and pipedream endpoint fails to work.

user-1 · April 17, 2025, 8:54pm

Can you show me the failure you’re getting?

user-1 · April 17, 2025, 8:54pm

Not sure why they wouldn’t work

user-1 · April 17, 2025, 8:54pm

I’ve increased the timout and im now seeing the problem.

user-1 · April 17, 2025, 8:54pm

Can you give me more details? Where are you seeing the issue? What tool are you trying to use?

user-1 · April 17, 2025, 8:54pm

2025-04-10 18:19:08,637 - mcp.client.sse - ERROR - Error parsing server message: 11 validation errors for JSONRPCMessage
JSONRPCRequest.method
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCRequest.jsonrpc
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCRequest.id
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCNotification.method
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCNotification.jsonrpc
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCResponse.jsonrpc
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCResponse.id
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCResponse.result
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCError.jsonrpc
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCError.id
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]
For further information visit Redirecting...
JSONRPCError.error
Field required [type=missing, input_value={‘type’: ‘connection_established’}, input_type=dict]

user-1 · April 17, 2025, 8:54pm

mcp library of python is bit more strict it seems.

user-1 · April 17, 2025, 8:54pm

going to https://actions.zapier.com/mcp/ss/sse (mcp zapier) doesn’t output {'type': 'connection_established'}, but pipedream https://mcp.pipedream.net/2sdf82c/google_calendar does

user-1 · April 17, 2025, 8:54pm

found the cause

user-1 · April 17, 2025, 8:54pm

github.com/modelcontextprotocol/python-sdk

src/mcp/client/sse.py

c4beb3e8e


      
          async with httpx.AsyncClient(headers=headers) as client:
              async with aconnect_sse(
                  client,
                  "GET",
                  url,
                  timeout=httpx.Timeout(timeout, read=sse_read_timeout),
              ) as event_source:
                  event_source.response.raise_for_status()
                  logger.debug("SSE connection established")
          
                  async def sse_reader(
                      task_status: TaskStatus[str] = anyio.TASK_STATUS_IGNORED,
                  ):
                      try:
                          async for sse in event_source.aiter_sse():
                              logger.debug(f"Received SSE event: {sse.event}")
                              match sse.event:
                                  case "endpoint":
                                      endpoint_url = urljoin(url, sse.data)
                                      logger.info(
                                          f"Received endpoint URL: {endpoint_url}"

user-1 · April 17, 2025, 8:54pm

the official mcp library sse_reader method.

user-1 · April 17, 2025, 8:54pm

within sse_client immediately tries to parse every incoming SSE message payload (sse.data) as a strict JSON-RPC message using types.JSONRPCMessage.model_validate_json(sse.data).
The Pipedream endpoint sends an initial, non-standard message {‘type’: ‘connection_established’} which doesn’t fit the JSON-RPC structure, causing the validation error

user-1 · April 17, 2025, 8:54pm

Did a monkey-patch to override the sse_reader method on my codebase and tried pipedream endpoint, and it works. So i can confirm this is the bug

user-1 · April 17, 2025, 8:54pm

user-1 · April 17, 2025, 8:54pm

We just pushed a fix — can you try again?

user-1 · April 17, 2025, 8:54pm

It works!!!

user-1 · April 17, 2025, 8:54pm

Thank you

user-1 · April 17, 2025, 8:54pm

Thank you! Thanks for debugging and for the pointer