Every design system is complete until you need a small outline button in a warning tone. Then you are writing custom CSS, and the system you adopted for consistency is what makes you inconsistent. ai2 makes that button a prop. 51 MIT components, each with a real variant x tone x size matrix on one OKLCH token layer, light and dark from one source. 307 styled variants and 8 presets on top. Built for the machine writing your UI too: machine-readable axes, llms.txt, MCP. Free core, no account.