resolved
The issue affecting Claude models has been resolved. Impact occurred from 16:28 PT / 23:28 UTC on October 23 to 16:59 PT / 23:59 UTC on October 23.
Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
Official Claude incident record with affected components, status, timeline updates, and links back to relevant status checks.
Affected components
These are the official Claude components attached to this incident. Component data can help separate a web app issue from an API, Console, or Claude Code issue.
claude.aiClaude API (api.anthropic.com)Claude CodeClaude Cowork
Official timeline
Updates are shown from the official Claude status incident record.
monitoring
We are seeing success rates return to normal for all affected models, and are continuing to monitor to ensure no further issues.
identified
We have identified the cause of elevated errors on requests to Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5, as well as fast mode requests to Opus 5.5 and are working on a fix. We will provide an update as soon as possible.
investigating
We are investigating elevated errors on requests to Claude Fable 5.1. We will provide an update as soon as possible.