OpenAI Apps, unsafe_url error

[ike.braun]

I try setup a custom app (https://openai.com/index/introducing-apps-in-chatgpt/) with an MCP server in the back. That MCP server uses Oauth authentication.

Going through the setup flow leads to an “unsafe_url error“ (See screenshot) that I cannot explain without further logs.

Any idea what might be going wrong?

[dooodle]

Got same error here for MCP server with OAuth setup.

I wonder if there’s any check on the domain name the MCP server address and OAuth urls.