Anthropic TypeScript SDK

What it does

• Tree-shakeable ESM + full TypeScript types — bundle-friendly for Vercel/Next.js
• Native support for Messages, Batch, Files, Token Counting, Vision
• Works in Node.js, browsers, Deno, Bun, Cloudflare Workers
• Streaming with delta events + tool-use streaming
• Vercel AI SDK, LangChain.js, Mastra, and most JS agents consume it

When to use it

Best for browser/Next.js apps calling Claude directly, edge functions on Cloudflare/Vercel, and any TypeScript agent framework that needs streaming responses and tool use. Pairs with Zod for typed tool inputs.

Getting started

npm install @anthropic-ai/sdk

Set ANTHROPIC_API_KEY (and ANTHROPIC_BASE_URL for Bedrock/Vertex) before importing.

Things to know

Pin to a major version in production — the SDK's TypeScript types change between minor releases. Tool-use streaming events require Node 18+ for stable behavior under backpressure.