Elevated errors for multiple models

Timeline

1. 13:26 UTC Claude Code status page · Reported Elevated errors for multiple models
2. 13:26 UTC Claude Code status page · Investigating We are investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. We will provide an update as soon as possible.
3. 13:41 UTC Claude Code status page · Identified We have identified the cause of elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and are working on a fix. We will provide an update as soon as possible.
4. 13:50 UTC Claude Code status page · Identified An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
5. 14:49 UTC Claude Code status page · Identified We are continuing to work on a fix for this issue.
6. 15:25 UTC Claude Code status page · Identified The only affected models right now are Opus 4.8 and Opus 5. The rest of the models have recovered to baseline error rate.
7. 16:06 UTC Claude Code status page · Monitoring A fix has been deployed for Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and we are monitoring for recovery.
8. 16:23 UTC Claude Code status page · Resolved The issue affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 has been resolved. Impact has ended as of 9:16 PT / 16:16 UTC.