Incident report · read from Anthropic's status page

Anthropic incident: Elevated errors for Mythos 5, Fable 5, Opus 5 and Claude Haiku 4.5

Resolved after 1 h 4 m (25 Jul 2026, 18:40–19:44 UTC), impact major, affecting Claude Cowork, Claude API (api.anthropic.com), claude.ai and Claude Code.

Timeline

1. 25 Jul 2026 at 18:40 UTC investigating

   We are investigating elevated errors on requests to Claude Mythos 5, Claude Fable 5, and Claude Haiku 4.5. We will provide an update as soon as possible.

2. 25 Jul 2026 at 18:44 UTC identified

   The issue has been identified and a fix is being implemented.

3. 25 Jul 2026 at 19:44 UTC resolved

   This incident has been resolved.

Affected components

• Claude Cowork: partial outage for 1 h 4 m
• Claude API (api.anthropic.com): partial outage for 1 h 4 m
• claude.ai: partial outage for 1 h 4 m
• Claude Code: partial outage for 1 h 4 m

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 8 Sep 2026 at 16:18 UTC.

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.