# cohere-rerank-v4.0-fast

Calls to the model cohere-rerank-v4.0-fast on Azure AI Foundry stop working on September 13, 2027.

On September 13, 2027, the cohere-rerank-v4.0-fast model will be retired on Azure AI Foundry. Any requests targeting model cohere-rerank-v4.0-fast will fail after this date. Services relying on this endpoint must transition before the retirement date to avoid service disruptions.

## What to use instead

Microsoft recommends moving to Cohere-rerank-v5-fast as the replacement.

- API: Azure AI Foundry (*.services.ai.azure.com)
- Model: cohere-rerank-v4.0-fast
- Kind: Model retirement
- Takes effect: September 13, 2027
- Calls after that day: fail
- Calls it hits: `model cohere-rerank-v4.0-fast`
- 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/cohere-rerank-v4.0-fast/

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