Anthropic API problems on 25 October 2026

Status	Resolved
Worst verdict	Some users report problems
Started	25 Oct 2026, 06:15 UTC
Ended	25 Oct 2026, 07:54 UTC
Duration	1 h 39 min
Official incident	Elevated errors for multiple models
Affected	Claude API (api.anthropic.com), claude.ai, Claude Code, Claude Cowork

Timeline

25 Oct 2026, 06:15 UTC

We started seeing problems. Our verdict: Some users report problems.
25 Oct 2026, 06:15 UTC · official update

Elevated errors for multiple models (investigating): “We are investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, and Claude Haiku 5.5. We will provide an update as soon as possible.” Source
25 Oct 2026, 06:28 UTC · official update

Elevated errors for Claude Sonnet 5.5 (identified): “We have identified the cause of elevated errors on requests to Claude Sonnet 5.5 and are working on a fix. We will provide an update as soon as possible.” Source
25 Oct 2026, 06:36 UTC · official update

Elevated errors for Claude Sonnet 5.5 and other models (monitoring): “A fix has been deployed for the issue affecting Claude services and we are monitoring for recovery.” Source
25 Oct 2026, 07:54 UTC

Looking normal again. We'll keep watching for 15 minutes before closing this.
25 Oct 2026, 08:08 UTC

Everything has looked normal for 15 minutes, so we marked this incident as resolved.

Times are shown in your local time zone. “Official update” entries quote Anthropic's status page; follow the source link for the full text.

How we track incidents

We open an incident when Anthropic API stops looking normal or Anthropic posts an official incident, and close it after 15 minutes with everything back to normal. More about our method.