HighDeprecation
Claude Opus 4.1 deprecated, retires August 5, 2026; sampler params return 400 on new models
claude-opus-4-1-20250805 was deprecated June 5, 2026 and retires August 5, 2026 (replacement: claude-opus-4-8); claude-mythos-preview retired June 30, 2026 in favor of claude-mythos-5. Separately, temperature/top_p/top_k return a 400 error when set to non-default values on Opus 4.7+, Opus 4.8, and Sonnet 5.
Action note
Audit API usage for claude-opus-4-1-20250805 and mythos-preview calls, migrate to claude-opus-4-8 / claude-mythos-5 before 2026-08-05, and strip non-default temperature/top_p/top_k from requests to newer models.
What to search in your codebase
- Claude Opus 4.1 deprecated, retires August 5, 2026; sampler params return 400 on new models
- Anthropic deprecation
- 2026-08-05
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