Make your AI websites look professional & beautiful. Copy-paste UI into v0, Cursor, Bolt, Lovable, Replit from the largest marketplace of UI elements. Get inspired by 50+ pro design engineers. Publish your design engineering work

21st Agents SDK is the fastest way to add an AI agent to your app. Define your agent in TypeScript, deploy in one command, and embed a production-ready chat UI with . Built-in streaming, session management, usage billing, and observability — so you can focus on what makes your agent unique, not infrastructure. Backed by Y Combinator (W26).

Why settle for one design, when you can start with five? With our new Magic Agent, you instantly get 5 unique component variants for any prompt — so you always find one you like, and you can instantly remix or micro-edit it in chat.