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21st Agents SDK
SDK to add an Claude Code AI agent to your app
221 votes·9 comments·Mar 7, 2026
About
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).