# devstral-small-2507

Calls to the model devstral-small-2507 on Mistral stopped working on May 31, 2026.

Mistral retired the model devstral-small-2507 on May 31, 2026. Requests specifying this model fail since that date. The change took effect following its announcement on February 27, 2026.

## The error Mistral returns once devstral-small-2507 is gone

HTTP 400

```json
{"object":"error","message":"Invalid model: devstral-small-2507","type":"invalid_model","param":null,"code":"1500"}
```

## What to use instead

Update your requests to use Mistral Small 4, which is recommended by Mistral as the replacement.

- API: Mistral (api.mistral.ai)
- Model: devstral-small-2507
- Kind: Model retirement
- Announced: February 27, 2026
- Takes effect: May 31, 2026
- Calls after that day: fail
- Calls it hits: `model devstral-small-2507`
- Source: [Lifecycle page](https://docs.mistral.ai/getting-started/models/models_overview/)
- Verified: November 6, 2026, against Mistral's own pages
- Page: https://www.okapi.bot/models/mistral/devstral-small-2507/

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