Kimi K3 model is now available in Kiro

Today, we are excited to announce that Kimi K3 model from Moonshot AI is available in Kiro, bringing the world’s first open-weight 2.8T-parameter model (according to Moonshot AI) directly into your agentic development workflow. With a 1-million-token context window, 2.8 trillion parameters, and a token-efficient mixture-of-experts architecture, Kimi K3 offers developers a unique combination of performance and efficiency for complex software development, and is a natural fit for the specification-driven, correctness-first approach that makes Kiro unique.

Kimi K3’s 1-million-token context window is large enough to hold entire codebases, full specification documents, test suites, and conversation history simultaneously. When you work through a specification-driven development workflow in Kiro, from requirements to design to implementation to verification, the model enables context continuity. With 2.8 trillion total parameters, K3 delivers frontier-level intelligence for tasks such as long-horizon coding, deep reasoning, and end-to-end knowledge work that matter most to professional developers. For Kiro users, this means a model that can reason through multi-file refactors, understand deeply nested dependency chains, and generate architecturally sound code across large codebases.

With the addition of Kimi K3, Kiro continues to expand the range of open-weight models available to developers, reinforcing our commitment to model choice with efficiency for routine tasks and powerful performance for complex work. Kimi K3’s reasoning capabilities can be chosen to enhance Kiro’s spec-driven development, translating requirements into executable specifications that are more thorough. Kiro’s automated, deterministic verification validates that the generated code matches the spec and developer intent. K3’s 1M context window allows it to consider the full system when identifying properties that should hold, and its 2.8 trillion parameters of knowledge produce implementations that are more likely to satisfy properties on the first pass. The combination delivers software that is not just functional, but verified against its specification.

Kimi K3 model is available today with experimental support to all Kiro Pro, Pro+, Pro Max, and Power customers in us-east-1 (IAD), and features a 2.4x credit multiplier for high-performance development work.