# o1-pro-2025-03-19

Calls to the model o1-pro-2025-03-19 on OpenAI stopped working on October 23, 2026.

The o1-pro-2025-03-19 model was retired on October 23, 2026. Requests specifying model o1-pro-2025-03-19 now fail instead of returning completions.

## The error OpenAI returns once o1-pro-2025-03-19 is gone

HTTP 404

```json
{"error":{"message":"The model `o1-pro-2025-03-19` has been deprecated, learn more here: https://platform.openai.com/docs/deprecations","type":"invalid_request_error","param":null,"code":"model_not_found"}}
```

## What to use instead

Move to gpt-5.6-sol (reasoning.mode: pro), recommended by OpenAI.

- API: OpenAI (api.openai.com)
- Model: o1-pro-2025-03-19
- Kind: Model retirement
- Takes effect: October 23, 2026
- Calls after that day: fail
- Calls it hits: `model o1-pro-2025-03-19`
- Source: [Deprecations page](https://developers.openai.com/api/docs/deprecations)
- Verified: November 6, 2026, against OpenAI's own pages
- Page: https://www.okapi.bot/models/openai/o1-pro-2025-03-19/

## OpenAI's words

> Shutdown date: October 23, 2026; Model snapshot: o1-pro-2025-03-19 | o1-pro; Substitute model: gpt-5.6-sol ( reasoning.mode: pro )

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent