xAI
grok-4 model retirement
Stopped workingSubscribe to xAIShare
Calls to the model grok-4 on xAI stopped working on May 15, 2026.
The error you get
What xAI answers a call to grok-4 once the model is gone, as recorded from real responses:
{"code":"invalid-argument","error":"Model not found: grok-4"}What to use instead of grok-4
Move to grok-4.3. Maps to grok-4.3 with reasoning effort "low". Grok 4 had no non-reasoning mode at all, so this is the first time the workload can be run without thinking tokens if you want that.
Facts
- API
- xAI
api.x.ai - Model
grok-4- Released
- July 9, 2024 (models.dev)
- Kind
- Model retirement
- Takes effect
- May 15, 2026
- Calls after that day
- Fail
- Source
- models.dev
- Last updated
- Verified
- , against xAI's own pages
Questions
When does grok-4 shut down?
Calls to the model grok-4 on xAI stopped working on May 15, 2026.
What happens to calls after May 15, 2026?
They have failed since May 15, 2026.
What error does grok-4 return once it is shut down?
xAI answers HTTP 400: "Model not found: grok-4". Send another model to fix it.
When was grok-4 released?
grok-4 was released on July 9, 2024, 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.
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You fixed this one by hand.
Okapi opens the pull request with the fix before the next breaking change reaches your code.