What is Arco?
Arco is the generative UI library for Kosmos. It provides the typed, themeable component vocabulary that AI agents assemble into chat blocks, workspace panels, and full installed apps.
Arco is not the operating system. Kosmos owns the shell, workspaces, agent UX, and focus model. Arco owns:
- Design tokens (
--arco-*) - UI primitives and layout patterns
- Generative blocks and their registry contract
- Runtime validation and render mapping for AI output
Why a separate library?
Separating Arco from Kosmos lets you:
- Ship the UI contract as a standard — other hosts (OpenClaw plugins, embedded React apps, MCP Apps) can render the same blocks without forking Kosmos.
- Keep generation bounded — the AI assembles from schema-validated blocks, not arbitrary HTML or CSS.
- Theme once, render everywhere — tokens flow from the OS shell into installed apps as
--os-*aliases.
Current status
The Kosmos prototype is an active monorepo. The shell uses Arco tokens and a growing ui/ + patterns/ library. Generative rendering today flows through OpenUI Lang (@openuidev/react-lang) with a planned migration to a unified block registry.
See the standards map for how Arco relates to AG-UI, MCP, and OpenUI.