The Kimi Code stack

The second structural choice is openness at both ends of the stack. At the bottom, the models themselves (the K2 and K3 families) are released as downloadable open weights on Hugging Face, and the CLI itself is MIT-licensed code on GitHub. At the top, the service exposes one coding API that speaks two wire protocols, OpenAI-compatible and Anthropic-compatible. That dual-protocol design is why the same membership works not only in Moonshot's own Kimi Code CLI and VS Code extension, but also inside third-party harnesses (a harness is the agent program that drives the model: its tools, prompts, and loop). The docs list Claude Code, OpenCode, Codex, and Hermes Agent as supported harnesses, plus Zed and JetBrains IDEs. Figure 1.1 puts the three layers in one picture.