Claude Sonnet 5.5 now available in AWS GovCloud (US)

Claude Sonnet 5.5 is now available in the Kiro IDE and CLI across AWS GovCloud (US-East) and AWS GovCloud (US-West). It is Anthropic's fastest Sonnet model to date and a natural upgrade for teams already using Sonnet 5: output is more than 30% faster, real-world coding and knowledge work approaches Opus 5.5 performance, and writing is clearer. It is available with a 1M-token context window and a 1.3x credit multiplier. Update to the latest IDE or CLI version, then restart it to access the model from the model selector. Learn more ->