Anthropic
claude-opus-4-1 model retirement
Stopped workingSubscribe to AnthropicShare
Anthropic retired model claude-opus-4-1 on August 5, 2026, following its deprecation on June 5, 2026. Calls specifying this model fail since that date. The change affects all requests targeting claude-opus-4-1 directly.
The error you get
What Anthropic answers a call to claude-opus-4-1 once the model is gone, as recorded from real responses:
{"type":"error","error":{"type":"not_found_error","message":"model: claude-opus-4-1"}}What to use instead of claude-opus-4-1
Move to claude-opus-4-8, which is recommended by Anthropic.
In Anthropic's words
API model name: claude-opus-4-1-20250805; Current state: Retired; Deprecated: June 5, 2026; Tentative retirement date: August 5, 2026
Facts
- API
- Anthropic
api.anthropic.com - Model
claude-opus-4-1- Released
- August 5, 2025 (models.dev)
- Kind
- Model retirement
- Announced
- June 5, 2026
- Takes effect
- August 5, 2026
- Calls after that day
- Fail
- Source
- Deprecations page
- Last updated
- Verified
- , against Anthropic's own pages
Questions
When does claude-opus-4-1 shut down?
Calls to the model claude-opus-4-1 on Anthropic stopped working on August 5, 2026.
What happens to calls after August 5, 2026?
They have failed since August 5, 2026.
What error does claude-opus-4-1 return once it is shut down?
Anthropic answers HTTP 404: "model: claude-opus-4-1". Send another model to fix it.
When was claude-opus-4-1 released?
claude-opus-4-1 was released on August 5, 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.
claude-opus-4-1 on other APIs 2
-
Azure AI Foundry
claude-opus-4-1Model retirement Stopped working -
No date
OpenCode
claude-opus-4-1Model retirement Deprecated, no date
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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.