#Claude Sonnet 4.5
1 published article
Claude Sonnet 4.5 deprecated: Anthropic retires claude-sonnet-4-5-20250929 on the Claude API on 30 November
Anthropic names Sonnet 5.5 as the replacement and gives 61 days' notice. Bedrock and Google Cloud set their own dates, and the new model changes how tool use and thinking behave.