Anthropic Confirms Elevated Errors Across Claude Opus 5 and Fable/Mythos APIs, Root Cause Unknown
Summary
Anthropic opened an incident on Claude Fable 5/5.1, Mythos 5/5.1 and Opus 5 at 00:57 UTC Sept 22, spanning claude.ai, the Claude API, Claude Code and Claude Cowork. Fable and Mythos have recovered to normal success rates, but Opus 5 is still throwing elevated errors while the team works on a fix. No root cause has been shared yet.
Originally reported by status.claude.com
Read the original article →Original headline: Anthropic Confirms Elevated Errors Across Claude Opus 5 and Fable/Mythos APIs, Root Cause Unknown