claude-opus-4-1-20250805: retirement date and replacement

This model retires on August 5, 2026. After that date, API calls naming it fail: there is no silent fallback to a newer model.

What actually happens

A request naming a retired model returns an API error. The part that catches teams out in production: nothing switches automatically to an equivalent model, and the error surfaces at call time, not at deploy time. Model IDs pinned in an environment file or an old evaluation script are the ones that break most often, because nobody re-reads them.

Check your own code

Search your code, environment variables and config files for the exact ID:

grep -rn "claude-opus-4-1-20250805" . --exclude-dir=node_modules

Source: Anthropic's official documentation — read on 8/2/2026, 8:56:57 PM UTC. See all models →