Case · 2026-08-24
Mythos, Fable, Opus: a three-hour error window
They named the models. They did not name the cause. The menu was the postmortem.
Summary: Status page reported elevated errors on Claude Mythos 5, Fable 5, Opus 5, Opus 4.8, and other models from 04:50 to 07:36 UTC on 24 Aug 2026. Cause identified, then resolved. Surfaces included claude.ai, the API, Claude Code, and Claude Cowork.
Source: status.claude.com · 24 Aug 2026
What landed
On 24 Aug 2026, status.claude.com opened an incident for elevated errors on multiple models.
Investigating at 05:06 UTC: Claude Mythos 5, Claude Fable 5, Claude Opus 5, and Claude Opus 4.8.
Identified at 05:27 UTC: cause found for Mythos 5, Fable 5, Opus 5, and other Claude models. No public description of that cause.
At 07:47 UTC, errors had stabilized on Opus 5 and Fable 5, with other models still being cleared.
Resolved at 08:30 UTC. Impact window in the resolution note: 9:50pm PT / 04:50 UTC through 00:36am PT / 07:36 UTC, including Claude Opus 5 and Fable 5.
Affected: claude.ai, Claude API, Claude Code, Claude Cowork.
Why it matters
A multi-hour stretch across the flagship models, not a single-model blip. Users on chat, API, Code, and Cowork shared the same window.
Satire margin
Four model names in the first update. Zero nouns for what broke.
Primary source
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