Claude Haiku 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). Haiku 5.5 is designed for high-volume work requiring quick responses. It has a 1M-token context window. Requests up to 100K tokens have a 0.06x credit multiplier; requests that exceed 100K tokens are billed at 0.3x. To load the latest model list, restart the IDE or CLI, run kirocrew restart for Crew, or refresh Web in your browser. Learn more ->
Models
Models
Claude Fable 5.1, Claude Sonnet 5.5, GPT-5.6 Terra, and GPT-5.6 Luna are generally available with full Kiro support. Expanded capacity supports more dependable access for production workloads. GPT-5.6 Sol remains Experimental. Fable 5.1 remains available to Kiro Enterprise organizations in US East (N. Virginia) (us-east-1). Sonnet 5.5 remains available across the Kiro IDE, CLI, Crew, and Web. GPT-5.6 Terra and Luna remain available in the Kiro IDE, CLI, and Web. Sonnet 5.5, GPT-5.6 Terra, and GPT-5.6 Luna are available for Pro, Pro+, Pro Max, and Power customers in the US and EU geographies. The Preview label for Fable 5.1 and Experimental labels for Sonnet 5.5, Terra, and Luna no longer apply. The Kiro Excluded Models indemnity exception also no longer applies to these models. To load the latest model list, restart the IDE or CLI, run kirocrew restart for Crew, or refresh Web in your browser. Learn more ->
Models
Kimi K3 is now available with experimental support across the Kiro IDE, CLI, Crew, and Web for Pro, Pro+, Pro Max, and Power customers using Kiro's US geography. Moonshot AI's open-weight model accepts text and images and has a 1M-token context window, making it well suited for long-running coding, reasoning, and knowledge work. Kimi K3 has a 2.4x credit multiplier and uses cross-region inference within the US geography. To load the latest model list, restart the IDE or CLI, run kirocrew restart for Crew, or refresh Web in your browser. Learn more ->
Models
Claude Sonnet 4 has reached end of life in Kiro as of October 14, 2026. If your work depends on it, choose another available model before continuing. Claude Sonnet 5.5 is the latest Sonnet model. See Model lifecycle for lifecycle stages and end-of-life dates.
Models
Claude Opus 5.5 is available in the Kiro IDE and CLI across both AWS GovCloud (US) Regions.
Claude Opus 5.5, Anthropic's most capable Opus model yet, is now available in the Kiro IDE and CLI across AWS GovCloud (US-East) and AWS GovCloud (US-West). It improves on Opus 5 for long-running agentic coding work and thinks adaptively on every request, deciding how much effort each task needs. It includes a 1M-token context window with a 2.0x credit multiplier, down from Opus 5's 2.2x. Update to the latest IDE or CLI version, then restart it to access the model from the model selector. Learn more ->
Models
Claude Sonnet 5.5 is available in the Kiro IDE and CLI across both AWS GovCloud (US) Regions.
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 ->
Models
Claude Sonnet 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). It's Anthropic's fastest Sonnet model to date and a clear upgrade over Sonnet 5: output is more than 30% faster, real-world knowledge work approaches Opus 5.5 performance, and clearer writing makes it a stronger collaborator. Claude Sonnet 5.5 includes a 1M-token context window, adaptive thinking on by default, and a 1.3x 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 ->
Models
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 ->
Models
Claude Fable 5.1 is beginning to roll out in Preview across Kiro clients for Kiro Enterprise organizations. Anthropic's most capable agentic coding model traces problems to root causes, maintains context and intent across complex tasks, and improves reliability for multi-file refactors and long autonomous runs. It has a 1M context window and a 6x credit multiplier. Inference runs only in US East (N. Virginia) (us-east-1).
Availability is limited during the Preview rollout. Organizations with access can enable Fable 5.1 through model governance. After model access management is enabled, administrators can add Fable 5.1 from Manage approved list and make it available to their users.
All Fable 5.1 traffic is retained for up to 30 days (unless otherwise required by law) for automated offline abuse detection. Classifier-flagged traffic will be subject to potential human review performed by AWS, and we may review flagged traffic for abuse. Learn more ->
Models
GPT-5.6 Sol, Terra, and Luna now support a 1M token context window, up from 272K, in the Kiro IDE, CLI, and Web. Entire codebases, long-form documents, and extended multi-turn agent histories fit in a single request, so repository-scale refactors, end-to-end debugging, and long-horizon agentic tasks run without chunking or losing earlier context. Credit multipliers for the GPT-5.6 family are updated with this launch and follow the two-tier context model OpenAI and Amazon Bedrock use: requests up to 272K tokens bill at the short context rate (Sol 4.4x, Terra 2.2x, Luna 1.1x), and requests above 272K tokens bill at double that rate. 1M context is rolling out gradually with experimental support to Kiro Pro, Pro+, Pro Max, and Power customers. Restart your IDE or CLI, or refresh Kiro Web, to see the updated models. Learn more ->