Breaking model

Claude Opus 3 (claude-3-opus-20240229) was retired on the Claude API January 5, 2026; requests to it now fail.

Took effect Jan 5, 2026 · Claude API model claude-3-opus-20240229 (alias claude-3-opus-latest)

Reviewed against the vendor source on Sep 24, 2026 (AI-assisted review). Key facts are re-checked against the source daily.

What changes

Anthropic notified developers of the retirement on June 30, 2025, and the model was retired January 5, 2026, with claude-opus-4-8 as the recommended replacement. These dates apply to Anthropic-operated platforms (Claude API, Claude Platform on AWS, Microsoft Foundry); Amazon Bedrock and Google Cloud set their own schedules.

Breaking: Calls fail after this date.

What to do

Switch to claude-opus-4-8 and test your application on it before cutting over. On Bedrock or Google Cloud, check that platform's own model table for its dates.

Strings to search for

claude-3-opus-20240229claude-3-opus-latest

Source

https://platform.claude.com/docs/en/about-claude/model-deprecations