# Custom Model Provider Error

**URL:** <https://forum.cursor.com/t/custom-model-provider-error/153948>\
**Category:** Bug Reports\
**Tags:** byok\
**Created:** [March 7, 2026, 5:05am UTC](https://forum.cursor.com/t/custom-model-provider-error/153948 "2026-03-07T05:05:56Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![deanrie](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/deanrie/32/1263_2.png) [@deanrie](https://forum.cursor.com/u/deanrie)\
**Post date:** [March 7, 2026, 6:59am UTC](https://forum.cursor.com/t/custom-model-provider-error/153948/3 "2026-03-07T06:59:07Z")

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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](http://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:

1. Switch from Agent mode to Ask mode. It uses the standard Chat Completions format and is more likely to work.
2. 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](https://forum.cursor.com/t/cursor-agent-sends-responses-api-format-to-chat-completions-endpoint/153019).

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.

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_[View the full topic](https://forum.cursor.com/t/custom-model-provider-error/153948)._