Fast mode for Claude Opus 5.5 leaves research preview and no longer requires access requests
Fast mode for Claude Opus 5.5 no longer requires an access request or a beta header. Existing requests with the header still work. The Start, Build and Scale tiers have a default request limit for this mode.
According to the release notes for Claude Platform, fast mode for Claude Opus 5.5 has left research preview. Access requests are no longer necessary, and requests do not require the fast-mode-2026-02-01 beta header. Requests that continue to include it still work.
Claude Opus 5.5 now has a default request limit for fast mode in the Start, Build and Scale usage tiers. The change does not apply to Claude Opus 5 and Claude Opus 4.8: fast mode for these models remains in research preview and still requires the beta header.
Why it matters
Developers can integrate the mode without first requesting access. When planning application capacity, however, they must account for the limit of the relevant usage tier; leaving research preview does not mean unlimited usage.
Two audiences, two different impacts
What this means
For individuals
When working with Claude Opus 5.5, you can start using fast mode without separate access approval.
For a business
Existing integrations with Claude Opus 5.5 continue to work with the beta header, so the change does not require an immediate update to requests.
DevelopmentCheck the original
Event sources
only one source so far · 1 publisher, 0 independent. We count feeds from the same owner only once.