Incident report · read from Anthropic's status page
Anthropic incident: Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1
Resolved after 15 m (5 Oct 2026, 13:05–13:21 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 and Claude Fable 5.1. We will provide an update as soon as possible.
- resolved
The issue affecting Claude Mythos 5.1 and Claude Fable 5.1 has been resolved. Impact occurred from 05:40 PT / 12:40 UTC to 06:10 PT / 13:10 UTC.
Affected components
- Claude Cowork: partial outage for 15 m
- Claude API (api.anthropic.com): partial outage for 15 m
- claude.ai: partial outage for 15 m
- Claude Code: partial outage for 15 m
What the crowd did
- 0 clicks, 3 zombies at their worst, 1 breaches, over 18 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 .
Must Have AI is a parody and is not affiliated with, endorsed by or connected to OpenAI, Anthropic or Google. Every outage shown here is read from the provider's own public status page.