The example on Readme is not working with Inspector tool

[LRagji]

Exact example on the readme.md is not working the with mcp inspector it returns an error saying not reachable. 404
Inspector logs
`
New StreamableHttp connection request
Query parameters: {"url":"http://localhost:3015/mcp","transportType":"streamable-http"}
Created StreamableHttp server transport
Created StreamableHttp client transport
Client <-> Proxy sessionId: d36fc01f-91e1-4d4b-ac39-37cce8c63d2d
Error accessing endpoint (HTTP 404)

When i debug i can see the connection being received in express app and follow it till await transport.handleRequest(req, res, req.body);` post which nothing else happens.

Latest version of lib 1.20.x

[cuijinyu]

same to me

[cuijinyu]

When working with Koa, you'll need to add the following to your code:

// Tell Koa not to handle the response since we're using the native res object directly
ctx.respond = false;

This prevents Koa from automatically handling the response when you're working directly with Node's native response object.

[cuijinyu]

@LRagji

[LRagji]

@cuijinyu i am using express, is that example for Koa?

[mattzcarey]

Hey @LRagji can you tell me a bit more about what's going wrong for you.

[LRagji]

I am doing a express app as per the example, but when I try to connect it with stream-able http client protocol mcp inspector fails to connect as I mentioned on my initial details..

[domdomegg]

The README example starts on port 3000 by default, not port 3015. And it uses express, not Koa. Perhaps there are some differences between your setup and the README?

It works out of the box for me and I cannot repro this issue. Are you able to provide any more details about how you are installing dependencies, running the server or what triggers the error?

[Hantar77]

New StreamableHttp connection request
Query parameters: {"url":"http://localhost:3015/mcp","transportType":"streamable-http"}
Created StreamableHttp server transport
Created StreamableHttp client transport
Client <-> Proxy sessionId: d36fc01f-91e1-4d4b-ac39-37cce8c63d2d
Error accessing endpoint (HTTP 404)
@felixweinberger