Hey, this is a known issue with Override OpenAI Base URL.
What’s happening: in Agent mode, Cursor is currently sending requests in the OpenAI Responses API format (input, flat tools format, etc.) instead of the standard Chat Completions format (messages, nested tools format). If your provider (api.gptsapi.net) only supports /v1/chat/completions, the request will fail. The empty error {"error":{"message":"","type":""}} points to this. The provider doesn’t understand the format and returns a vague response.
What you can try:
- Switch from Agent mode to Ask mode. It uses the standard Chat Completions format and is more likely to work.
- Go to Cursor Settings > Network > HTTP Compatibility Mode and switch to HTTP/1.1. Custom endpoints often don’t work well with HTTP/2.
More details: Cursor Agent sends Responses API format to /chat/completions endpoint.
The team is aware of this issue. There’s no timeline yet, but reports like this help with prioritization. Let me know if Ask mode helps.