# claude-opus-4-1

Calls to the model claude-opus-4-1 on Anthropic stopped working on August 5, 2026.

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 Anthropic returns once claude-opus-4-1 is gone

HTTP 404

```json
{"type":"error","error":{"type":"not_found_error","message":"model: claude-opus-4-1"}}
```

## What to use instead

Move to claude-opus-4-8, which is recommended by Anthropic.

- 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
- Calls it hits: `model claude-opus-4-1`
- Source: [Deprecations page](https://platform.claude.com/docs/en/about-claude/model-deprecations)
- Verified: November 6, 2026, against Anthropic's own pages
- Page: https://www.okapi.bot/models/anthropic/claude-opus-4-1/

## Anthropic's words

> API model name: claude-opus-4-1-20250805; Current state: Retired; Deprecated: June 5, 2026; Tentative retirement date: August 5, 2026

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