Claude Status – Elevated errors for multiple models

Anthropic's Claude status page reported elevated errors affecting multiple Claude models and services, with the incident affecting claude.ai, the Claude API at api.anthropic.com, Claude Code, and Claude Cowork. The first notice, posted Sep 22, 2026 at 00:57 UTC, said the company was investigating elevated errors on requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5, and would provide an update as soon as possible.

At 01:17 UTC, Anthropic said it had identified the cause of the elevated errors on those same three models—Mythos 5.1, Fable 5.1, and Opus 5—and was working on a fix, with another update promised as soon as possible. The next update at 01:35 UTC said work continued to resolve errors affecting some models; by then, requests to Claude Fable 5 and 5.1 and Mythos 5 and 5.1 had returned to normal success rates, while Anthropic was still working to resolve remaining errors affecting Claude Opus 5 and would provide an additional update shortly.

The latest update, posted at 02:11 UTC, moved the incident into monitoring: success rates had returned to normal across affected models, and Anthropic said it was monitoring closely to ensure no further issues.