Build a Custom Agent with the Claude Agent SDK in 10 Lines

The Claude Agent SDK (formerly Claude Code SDK) gives you the same tools and agent loop that power Claude Code, but as a library you can call from Python or TypeScript. No tool implementations needed.

import asyncio
from claude_agent_sdk import query, ClaudeAgentOptions

async def main():
    async for message in query(
        prompt="Find all TODO comments and create a summary",
        options=ClaudeAgentOptions(
            allowed_tools=["Read", "Glob", "Grep"]
        ),
    ):
        if hasattr(message, "result"):
            print(message.result)

asyncio.run(main())

Built-in tools include Read, Write, Edit, Bash, Glob, Grep, WebSearch, and WebFetch. You don't have to implement any of them. Just list what the agent should have access to in allowed_tools.

Install with pip install claude-agent-sdk or npm install @anthropic-ai/claude-agent-sdk, set ANTHROPIC_API_KEY, and you're running. The SDK also supports Bedrock, Vertex AI, and Azure for enterprise auth.

Sessions persist automatically. Capture session_id from the init message and pass it back with resume=session_id to continue a conversation with full context.

Same power as Claude Code, now programmable in your own applications.

via Claude Code Docs — SDK