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Written by AI from the official notes. Check them for exact details.Fast mode has been removed for Claude Opus 4.6, reverting to standard speed and pricing.
- Fast mode for Claude Opus 4.6 is no longer available.
- Requests now run at standard speed and rates.
- Usage speed is reported in the response's usage.speed field.
- Users should migrate to Claude Opus 4.8 for fast mode.
Why it matters: Users of Claude Opus 4.6 should transition to Claude Opus 4.8 for fast mode functionality.
Full release notes
- We've removed fast mode for Claude Opus 4.6. Requests to
claude-opus-4-6withspeed: "fast"no longer run at fast speed or premium pricing: they run at standard speed, are billed at standard rates, and do not return an error. The response'susage.speedfield reports the speed used. To continue using fast mode, migrate to Claude Opus 4.8. Read more in Fast mode.