Major incident

Anthropic (Claude): Elevated errors for Claude Mythos 5, Claude Fable 5, and Claude Sonnet 5

Affected: claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork

Current status of Anthropic (Claude): Operational — live Anthropic (Claude) status

Timeline

1. Aug 13, 2026, 14:33 UTC
   investigating
   We are investigating elevated errors on requests to Claude Mythos 5, Claude Fable 5, and Claude Sonnet 5. We will provide an update as soon as possible.
2. Aug 13, 2026, 15:44 UTC
   investigating
   We are investigating elevated errors on requests to Claude Mythos 5 and Claude Fable 5. We will provide an update as soon as possible.
3. Aug 13, 2026, 16:08 UTC
   resolved
   The issue affecting Claude Mythos 5 and Claude Fable 5 has been resolved.

Updates as published by Anthropic (Claude) (original).