Features
- Type-safe API for all Claude models
- Streaming responses with Server-Sent Events
- Tool use (function calling) support
- Vision capabilities for image understanding
Pros
- Direct access to the most capable Claude models
- Excellent TypeScript types and documentation
- First-party SDK with guaranteed API compatibility
Cons
- Only works with Anthropic's Claude models
- Requires API key and usage-based billing
- Rate limits apply depending on tier
Overview
The Anthropic Claude SDK is the official client library for interacting with Claude AI models. Available for TypeScript/JavaScript and Python, it provides a type-safe, idiomatic interface to the Anthropic Messages API, supporting text generation, tool use, vision, and streaming.
The SDK handles authentication, request formatting, response parsing, retry logic, and streaming. It supports all Claude model variants (Opus, Sonnet, Haiku) and provides full access to features like system prompts, multi-turn conversations, tool use for function calling, and image understanding.
For TypeScript developers, the SDK provides comprehensive type definitions that make it easy to work with the API without consulting documentation for every request/response field.
When to Use
Use the Anthropic SDK when you need direct, low-level access to Claude models. For higher-level abstractions like agent loops or multi-provider support, consider the Vercel AI SDK or LangChain.
Getting Started
npm install @anthropic-ai/sdkimport Anthropic from '@anthropic-ai/sdk'
const client = new Anthropic()
const message = await client.messages.create({
model: 'claude-sonnet-4-5-20250929',
max_tokens: 1024,
messages: [{ role: 'user', content: 'Hello, Claude!' }]
})