Elevated errors for Claude Mythos 5, Claude Fable 5, and Claude Sonnet 5

Incident Report for Claude

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.
Posted Aug 13, 2026 - 14:33 UTC
This incident affects: claude.ai, Claude API (api.anthropic.com), Claude Code, and Claude Cowork.