Claude Sonnet 5 Now Available

Claude Sonnet 5 is now available in the Kiro IDE, CLI, and Web. It's Anthropic's most agentic Sonnet model yet, a substantial upgrade from Sonnet 4.6 with stronger reasoning, tool use, and coding that approaches Opus 4.8 performance at Sonnet-class pricing. Plans before it edits, runs longer without supervision, and checks its own output without being asked. Sonnet 5 is rolling out gradually with experimental support to Kiro Pro, Pro+, Pro Max, and Power customers in the AWS US-East-1 (Northern Virginia) and AWS Europe (Frankfurt) regions, with cross-region inference support. It ships with the full 1M context window, 1.3x credit multiplier, the same as Sonnet 4.6. Restart your IDE or CLI to access it from the model selector. Learn more ->