21st Agents SDK – Integrate Claude Code AI agents into your app with minimal infrastructure

Summary: 21st Agents SDK enables developers to add Claude Code AI agents to applications by defining agents in TypeScript, deploying with a single command, and embedding a production-ready chat UI. It includes built-in streaming, session management, usage billing, and observability, reducing the need to build complex infrastructure.

What it does

The SDK allows defining AI agents using TypeScript and deploys them via a command-line tool that manages sandboxed cloud execution. It provides a drop-in React chat UI with streaming, tool execution rendering, theming, and built-in observability features like session replay and error tracking.

Who it's for

It targets developers building AI-powered applications who want to integrate advanced Claude Code agents without creating underlying infrastructure.

Why it matters

It solves the challenge of building and maintaining complex agent infrastructure by offering a managed, production-ready platform that keeps user code in their codebase while handling execution and observability.