Official Claude API incident · Oct 5, 2026

Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1

Major impact Claude API incident on Oct 5, 2026, lasting 16 min. Read the official timeline and compare it with community reports from the same day.

ImpactMajor impactDuration16 minFinal statusresolved

Official timeline

What happened

Oct 5, 2026, 1:05 PM UTCinvestigating

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.

Oct 5, 2026, 1:21 PM UTCresolved

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.

Official incident details come from Anthropic Status. Community reports are voluntary submissions, not unique users or verified incident attribution. claudedumb.com is independent and not affiliated with Anthropic.