Mentioned in the evidence
- Claude Opus 4.8 fast mode
- claude-opus-4-8 requests with speed: "fast"
Official source
- Anthropic Claude release notes (changelog) ↗
We’ve deprecated fast mode for Claude Opus 4.8, with removal on November 30, 2026. After removal, requests to claude-opus-4-8 with speed: "fast" will return an error. To continue using fast mode, migrate to Claude Opus 5.5. Read more in Fast mode.
This is a global change, verified against Anthropic’s own sources. It is not an assessment of your systems or your impact.