# Anthropic: Elevated errors for multiple models

- Impact (vendor’s label): major
- Status: resolved
- Started: 2026-09-03 13:26 UTC · Resolved: 2026-09-03 16:23 UTC · Duration: 3.0 h
- Updates: 7 · Affected components: Claude Cowork, Claude API (api.anthropic.com), claude.ai, Claude Code
- [Vendor status page: https://stspg.io/9xz4hhmd1jzn](https://stspg.io/9xz4hhmd1jzn)
- [Company: Anthropic](https://rewindex.com/company/anthropic.md)

## Summary

Anthropic reported a major incident causing elevated request errors across claude.ai, Claude API (api.anthropic.com), Claude Code, and Claude Cowork, initially affecting Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5. Starting 2026-09-03 13:26 UTC, it was resolved at 2026-09-03 16:23 UTC (2 h 57 min); a fix was deployed. _(machine-written, sol)_
## Discussed on Hacker News

- [Ask HN: Why were OpenAI, Claude, and Grok simultaneously down?](https://news.ycombinator.com/item?id=49551096): 404 points, 705 comments, posted 2026-09-03 15:07 UTC, posted 101 min after the vendor’s first update
- [Claude outage – Resolved](https://news.ycombinator.com/item?id=49549676): 205 points, 151 comments, posted 2026-09-03 13:29 UTC, posted 3 min after the vendor’s first update

## Timeline of updates

- **investigating** 2026-09-03 13:26 UTC: 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.
- **identified** 2026-09-03 13:41 UTC: 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.
- **identified** 2026-09-03 13:50 UTC: An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
- **identified** 2026-09-03 14:49 UTC: We are continuing to work on a fix for this issue.
- **identified** 2026-09-03 15:25 UTC: The only affected models right now are Opus 4.8 and Opus 5. The rest of the models have recovered to baseline error rate.
- **monitoring** 2026-09-03 16:06 UTC: A fix has been deployed for Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 and we are monitoring for recovery.
- **resolved** 2026-09-03 16:23 UTC: 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.

## Rewindex changes for this incident

- 2026-09-03 13:26 UTC: [Major incident: Elevated errors for multiple models](https://rewindex.com/change/ic6c11dcef3fa28.md)


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Canonical: https://rewindex.com/company/anthropic/incidents/461yvfrzpwtt · Markdown: https://rewindex.com/company/anthropic/incidents/461yvfrzpwtt.md · JSON: https://rewindex.com/api/v1/companies/anthropic/incidents/461yvfrzpwtt · Generated 2026-10-18T08:09:09.092Z