Okapi Okapi

Azure AI Foundry grok-4-fast-non-reasoning model retirement

Stopped workingSubscribe to Azure AI FoundryShare

The model grok-4-fast-non-reasoning was retired on May 1, 2026. Calls to this model fail since that date. The change affects all requests targeting model grok-4-fast-non-reasoning.


What to use instead of grok-4-fast-non-reasoning

Switch to grok-4-1-fast-non-reasoning, which stops working on May 19, 2027. No replacement that holds is named yet.

In Azure AI Foundry's words

Model: grok-4-fast-non-reasoning; Version: 1; Lifecycle: Retired; Retirement date: 2026-05-01; Replacement: grok-4-1-fast-non-reasoning

Azure AI Foundry, Deprecations page

Facts

API
Azure AI Foundry *.services.ai.azure.com
Model
grok-4-fast-non-reasoning
Released
December 18, 2025 (models.dev)
Kind
Model retirement
Takes effect
May 1, 2026
Calls after that day
Fail
Source
Deprecations page
Last updated
Verified
, against Azure AI Foundry's own pages

Questions

When does grok-4-fast-non-reasoning shut down?

Calls to the model grok-4-fast-non-reasoning on Azure AI Foundry stopped working on May 1, 2026.

What happens to calls after May 1, 2026?

They have failed since May 1, 2026.

When was grok-4-fast-non-reasoning released?

grok-4-fast-non-reasoning was released on December 18, 2025, according to models.dev.

How do I find the calls this hits in my code?

Okapi reads your repository, finds the calls this change hits and opens a pull request with the fix. It never commits to your branches: every change comes as a pull request you review.


grok-4-fast-non-reasoning on other APIs 1

  1. xAI grok-4-fast-non-reasoningModel retirement Redirected

More from Azure AI Foundry 10

  1. grok-3Model retirement Stopped working
  2. grok-3-miniModel retirement Stopped working
  3. grok-4-fast-reasoningModel retirement Stopped working
  4. cohere-command-r-08-2024Model retirement Stopped working
  5. cohere-command-r-plus-08-2024Model retirement Stopped working
  6. gpt-5-chatModel retirement Stopped working
  7. gpt-5.2-chatModel retirement Stopped working
  8. cohere-rerank-v3.5Model retirement Stopped working
  9. llama-3.2-11b-vision-instructModel retirement Stopped working
  10. llama-3.2-90b-vision-instructModel retirement Stopped working

You fixed this one by hand.

Okapi opens the pull request with the fix before the next breaking change reaches your code.

Add to GitHub

Get notifications

Subscribe to Azure AI Foundry

Hear about each breaking change Azure AI Foundry announces, in your feed reader, calendar or Slack.

1What to follow

Provider
  • Azure AI Foundry

2Where to get it

/breaking-changes/feed.xml

Paste it into Feedly, Inoreader, NetNewsWire or any reader. New changes show up as they're announced.