# claude-sonnet-4-5

Calls to the model claude-sonnet-4-5 on Azure AI Foundry stop working on November 30, 2026.

On November 30, 2026, the model claude-sonnet-4-5 will be retired. Calls targeting model claude-sonnet-4-5 will fail after that day.

## What to use instead

Move to claude-sonnet-5-5, which is recommended by Microsoft.

- API: Azure AI Foundry (*.services.ai.azure.com)
- Model: claude-sonnet-4-5
- Kind: Model retirement
- Takes effect: November 30, 2026
- Calls after that day: fail
- Calls it hits: `model claude-sonnet-4-5`
- Source: [Deprecations page](https://learn.microsoft.com/en-us/azure/foundry/openai/concepts/model-retirement-schedule)
- Verified: October 29, 2026, against Azure AI Foundry's own pages
- Page: https://www.okapi.bot/models/azure-ai-foundry/claude-sonnet-4-5/

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