Incident report · read from Anthropic's status page
Anthropic incident: Elevated errors for multiple models
Resolved after 1 h 37 m (22 Sep 2026, 00:57–02:35 UTC), impact major, affecting Claude Cowork, Claude API (api.anthropic.com), claude.ai and Claude Code.
Timeline
- investigating
We are investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. We will provide an update as soon as possible.
- identified
We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible.
- identified
We are continuing to work to resolve errors affecting some models. At this time, requests to Claude Fable 5 and 5.1 and Mythos 5 and 5.1 have returned to normal success rates. We are working to resolve remaining errors affecting Claude Opus 5, and will provide an additional update shortly.
- monitoring
We have seen success rates return to normal across affected models, and are monitoring closely to ensure no further issues.
- resolved
This issue has been resolved. Impact occurred from 5:50pm PT / 00:50 UTC to 7:10pm PT / 02:10 UTC.
Affected components
- Claude Cowork: partial outage for 1 h 14 m
- Claude API (api.anthropic.com): partial outage for 1 h 14 m
- claude.ai: partial outage for 1 h 14 m
- Claude Code: partial outage for 1 h 14 m
What the crowd did
- 0 clicks, 3 zombies at their worst, 7 breaches, over 1 h 40 m — the siege in full
That is this site's own record of the crowd at Anthropic's gate, not anything Anthropic published.
Source
Anthropic's own report of this incident, on Anthropic's status page. This page is a record of Anthropic's own report; where the two disagree, theirs is right.
Last checked .
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