AI & models
Agent SDK
Claude Agent SDK
A toolkit for TypeScript or Python that gives your own program the full Claude Code engine as a library — the agent loop, tools, permissions, context management, MCP, hooks and subagents — instead of a chat window around it.
Why it matters
Part of Building Claude into your own software → It's the difference between using Claude and building with it. The raw API gives you the brain: one exchange, one reply. The Agent SDK gives you the brain plus the body — the loop that runs a tool, reads the result and decides what to do next, which is most of the hard work in any agent. Roughly: Claude Code with the front door removed so you can wire your own onto the same room.
see also