# 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, Azure AI Foundry will retire model claude-sonnet-4-5. After this date, calls targeting this model will fail. Ensure your integration is updated before the retirement date to avoid service disruptions.

## What to use instead

Move to claude-sonnet-5-5, as recommended by Microsoft.

- API: Azure AI Foundry (*.services.ai.azure.com)
- Model: claude-sonnet-4-5
- Released: September 29, 2025 (models.dev)
- 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: November 6, 2026, against Azure AI Foundry's own pages
- Page: https://www.okapi.bot/models/azure-ai-foundry/claude-sonnet-4-5/

## Azure AI Foundry's words

> Model: claude-sonnet-4-5; Version: 1; Lifecycle: GA; Retirement date: 2026-11-30; Replacement: claude-sonnet-5-5

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