claude-agent-sdk

Claude Agent SDK

Overview

The Claude Agent SDK enables building autonomous AI agents with Claude through a feedback loop architecture. Available for Python (3.10+) and TypeScript (Node 18+).

Repository:

• Python: https://github.com/anthropics/claude-agent-sdk-python
• TypeScript: https://github.com/anthropics/claude-agent-sdk-typescript

Documentation: https://platform.claude.com/docs/en/agent-sdk/overview

Installation

# Python
pip install claude-agent-sdk

# TypeScript
npm install @anthropic-ai/agent-sdk

Core Architecture: Feedback Loop Pattern

Every agent follows this cycle:

1. Gather Context → filesystem navigation, subagents, tools
2. Take Action → tools, bash, code generation, MCP
3. Verify Work → rules-based, visual, LLM-as-judge
4. Repeat → iterate until completion

This pattern applies whether you're building a simple script or a complex multi-agent system.

Execution Mechanisms (Priority Order)

Choose mechanisms based on task requirements:

1. Custom Tools → Primary workflows (appear prominently in context)
2. Bash → Flexible one-off operations
3. Code Generation → Complex, reusable outputs (prefer TypeScript for linting feedback)
4. MCP → Pre-built external integrations (Slack, GitHub, databases)

Rule: Use tools for repeatable operations, bash for exploration, code generation when you need structured output that can be validated.

Quick Start Patterns

Python: Basic Query

from claude_agent_sdk import query

result = await query(
    model="claude-sonnet-4-5",
    system_prompt="You are a helpful coding assistant.",
    user_message="List files in current directory",
    working_dir=".",
)
print(result.final_message)

TypeScript: Session Management

import { ClaudeSdkClient } from '@anthropic-ai/agent-sdk';

const client = new ClaudeSdkClient({ apiKey: process.env.ANTHROPIC_API_KEY });

const result = await client.query({
  model: 'claude-sonnet-4-5',
  systemPrompt: 'You are a helpful coding assistant.',
  userMessage: 'List files in current directory',
  workingDir: '.',
});

console.log(result.finalMessage);