Every AI release note

We've removed fast mode for Claude Opus 4.6

Requests to claude-opus-4-6 with speed: "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's usage.speed field reports the speed used. To continue using fast mode, migrate to Claude Opus 4.8. Read more in Fast mode.