What is export?

export lets you write normal functions and classes on a Cloudflare Worker, then import them from any client -- browser, Node.js, Deno, or another Worker -- using just the Worker URL.

// On the server: write functions as usual
export function greet(name) {
  return `Hello, ${name}!`;
}

// On the client: import from the Worker URL
import { greet } from "https://my-worker.workers.dev/";
await greet("World");  // "Hello, World!"

No SDK. No code generation. No client-side build step.

How it works

1. Your Worker exports functions and classes in src/index.ts
2. When a client imports the Worker URL, a tiny ESM glue module is returned
3. That module opens a WebSocket and creates Proxy objects for each export
4. Function calls are serialized with devalue and sent over WebSocket
5. Results come back as promises

The core client library (~5KB) is served with immutable caching and changes path on each deploy for automatic cache busting.

Key features

• Zero-config client -- just import from a URL
• Path-based imports -- import greet from ".../greet"
• Classes -- remote instantiation with Comlink-style proxies
• Streaming -- ReadableStream and AsyncIterator support
• Shared exports -- cross-client shared state via Durable Objects
• TypeScript -- precise types generated at build time with oxc-parser
• Rich serialization -- Date, Map, Set, BigInt, URL, TypedArrays, and more