# mistral-small-2506

Calls to the model mistral-small-2506 stopped working on July 31, 2026.

Requests specifying model mistral-small-2506 fail since July 31, 2026. Mistral announced the retirement on April 30, 2026, and permanently shut down the model on the effective date. Any API requests targeting mistral-small-2506 now return errors.

## The error Mistral returns once mistral-small-2506 is gone

HTTP 400

```json
{"object":"error","message":"Invalid model: mistral-small-2506","type":"invalid_model","param":null,"code":"1500"}
```

## What to use instead

Mistral recommends migrating to Mistral Small 4.

- API: Mistral (api.mistral.ai)
- Model: mistral-small-2506
- Released: June 20, 2025 (models.dev)
- Kind: Model retirement
- Announced: April 30, 2026
- Takes effect: July 31, 2026
- Calls after that day: fail
- Calls it hits: `model mistral-small-2506`
- 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/mistral-small-2506/

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