- Level
- confirmed
- Worst impact
- Partial outage
- Components
- claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork
- Down Index
- 58of 100
What to do
Check whether you use Anthropic claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork. Check your stack
Paste a package.json, lockfile, Terraform or a list of domains at down.guide/stack to see every provider you depend on.Confirm your retries, queues and scheduled jobs caught up after the 2h 57m it lasted.
Anything that failed between 2026-09-03 13:26 UTC and 2026-09-03 16:23 UTC may need a replay.Subscribe to Anthropic's feed to hear about the next one first. RSS feed
https://down.guide/feed?provider=anthropic works in Slack (/feed subscribe), Discord feed bots and any RSS reader.
Updates from Anthropic 7
- 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.
provider
- 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.
provider
- identified
An exhaustive list of affected models: Mythos/Fable 5.1, Mythos/Fable 5, Opus 5, Opus 4.8, Opus 4.6.
provider
- identified
We are continuing to work on a fix for this issue.
provider
- 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.
provider
- 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.
provider
- 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.
provider
Reports count in aggregate; nothing about you is shown.
Corrections
None so far.
Something wrong on this page? Report an error or send us a note. Every fix is listed here.
Questions about DWN-66864c34c6
Is Anthropic still down?
No, this incident was resolved 2026-09-03 16:23 UTC. For Anthropic's live state, see https://down.guide/anthropic.
How long did it last?
2h 57m, from 2026-09-03 13:26 UTC to 2026-09-03 16:23 UTC, by the times Anthropic posted.
What was affected?
Anthropic named claude.ai, Claude API (api.anthropic.com), Claude Code, Claude Cowork.
What caused it?
Anthropic hasn't published a root cause. If it does, it shows here.
Where does this come from?
Anthropic's official status page, https://status.claude.com, quoted verbatim. down.guide's own probes, reports and social counts are labeled as ours.