← AIFast Developer Hub

OpenAI Base URL Checker

Find the common /v1/v1 and full-endpoint mistakes before Cursor, Dify or an OpenAI-compatible client returns a confusing 404.

Everything runs in this browser. The Base URL is not uploaded. Do not paste an API key here.

Base URL Client behavior

What this catches

https://host/v1 plus a client that appends /v1 becomes /v1/v1.
A full /chat/completions URL is not a Base URL when the client appends its own endpoint.
Different clients may use Chat Completions or Responses paths. Check the final request URL in the client logs.

After the URL check

Use a limited test key only after the URL is correct. Check the online model gateway checker for protocol behavior, then follow the AIFast start path if you need an account.