An outage on May 15, 2026 disrupted requests to Anthropic’s Claude Opus and Sonnet 4.6, while Opus 4.7 returned to normal operation. Developers using the Claude API (api.anthropic.com) reported increased error rates across the board.

The incident, logged on the company’s Atlassian Statuspage, prompted a rapid investigation. Anthropic’s engineering team confirmed that the problem affected both the standard Claude service and its code‑generation companion, Claude Code.

Clients relying on real‑time responses saw slowed performance and higher failure counts, potentially impacting downstream services that integrate the model for content generation and code assistance.

Anthropic has issued a status update, stating the team is still probing the root cause and will release a fix once the underlying issue is resolved.