Kiro: Claude Opus 5.5 Now Available

September 28, 2026 Claude Opus 5.5 Now Available Claude Opus 5.5 brings stronger agentic coding and clearer communication than Opus 5 at a 2.0x credit multiplier, down from Opus 5's 2.2x. Claude Opus 5.5 is now available with experimental support across the Kiro IDE, CLI, Crew, and Web for Pro, Pro+, Pro Max, and Power customers in us-east-1 (IAD) and eu-central-1 (FRA). Anthropic reports stronger performance on long, complex coding tasks and clearer communication than prior models. Claude Opus 5.5 includes a 1M-token context window and has a 2.0x credit multiplier . To load the latest model list, restart the IDE or CLI, run kirocrew restart for Crew, or refresh Web in your browser. Learn more -> { PREVIOUS } Claude Opus 5 Now Available { NEXT } Claude Opus 4.8 Now Available