# disable_reasoning on POST /v1/chat/completions stops working

Calls to POST /v1/chat/completions, body parameter disable_reasoning on Cerebras stopped working on July 21, 2026.

- API: Cerebras (api.cerebras.ai)
- Kind: Endpoint removal
- Announced: March 24, 2026
- Takes effect: July 21, 2026
- Calls after that day: fail
- Calls it hits: `POST /v1/chat/completions`, `body parameter disable_reasoning`
- Source: [Announcement](https://inference-docs.cerebras.ai/support/deprecation)
- Page: https://www.okapi.bot/providers/cerebras/breaking-changes/disable-reasoning-on-post-v1-chat-completions-stops-working/

## What to use instead

Use reasoning_effort="none" to disable reasoning.