Incident report · read from Anthropic's status page

Anthropic incident: Degraded performance for multiple models

Resolved after 2 h 41 m (18 Aug 2026, 16:20–19:01 UTC), impact minor, affecting Claude Cowork, Claude API (api.anthropic.com), claude.ai and Claude Code.

Timeline

  1. investigating

    We are investigating reports of degraded performance affecting multiple models. We will provide an update as soon as possible.

  2. investigating

    We are investigating elevated errors on requests to Claude Mythos 5, Claude Fable 5, Claude Opus 5, Claude Sonnet 5, Claude Haiku 4.5, and other Claude models. We will provide an update as soon as possible.

  3. investigating

    We are investigating elevated errors on requests to Claude Opus 5. We will provide an update as soon as possible.

  4. monitoring

    A fix has been implemented and we are monitoring the results.

  5. resolved

    The issue affecting Claude Opus 5 has been resolved. Impact occurred from 16:11 to 18:23 UTC.

Affected components

Source

Anthropic's own report of this incident, on Anthropic's status page. This page is a record of Anthropic's own report; where the two disagree, theirs is right.

Last checked .

Must Have AI is a parody and is not affiliated with, endorsed by or connected to OpenAI, Anthropic or Google. Every outage shown here is read from the provider's own public status page.