bug: v0.39.0 does not work at all

[matheuscscp]

Hi, I have an MCP server that works fine through stdio and streamable HTTP in v0.38.0, then if I bump to v0.39.0 it simply stops working in both transports, neither Claude Web nor Claude Desktop work with it, they can't even query the available tools, and no logs are printed anywhere (I guess for obvious reasons in the case of stdio).

[fatemehpourghaemi]

Faced the same issue. Downgraded to v0.38.0.

[matheuscscp]

The last good commit is 4e353ac

The first bad commit is b924391, from #571

[alex210501]

👋 Hey

Really sorry for this, the issue is coming from the fact that you cannot return an empty outputSchema. I'm working on a fix and will post it here.

[alex210501]

By looking at the code, I believe that the same issue might also happen with an empty inputSchema so it might be interesting to keep this in view.

[alex210501]

There is the fix

[matheuscscp]

The fix in v0.39.1 works for me, thanks very much!!

[alex210501]

Thank you for the feedback @matheuscscp, and sorry again

[ezynda3]

Thanks @matheuscscp and @alex210501 for helping with this so quickly!