npm for design engineers — shadcn/ui component marketplace
21st.dev is the largest open-source marketplace of shadcn/ui-based React Tailwind components, blocks, and hooks. Used by 1.4M developers with 200K monthly active users. Functions as an MCP server enabling AI coding agents to discover and compose UI components via API. Features a Magic AI feature that generates components from natural language prompts. All components installable with npx shadcn.
