net

To enable built-in Node.js APIs and polyfills, add the nodejs_compat compatibility flag to your Wrangler configuration file. This also enables nodejs_compat_v2 as long as your compatibility date is 2024-09-23 or later. Learn more about the Node.js compatibility flag and v2.

You can use node:net ↗ to create a direct connection to servers via a TCP sockets with net.Socket ↗.

These functions use connect functionality from the built-in cloudflare:sockets module.

JavaScript

index.js

import net from "node:net";

const exampleIP = "127.0.0.1";

export default {
  async fetch(req) {
    const socket = new net.Socket();
    socket.connect(4000, exampleIP, function () {
      console.log("Connected");
    });

    socket.write("Hello, Server!");
    socket.end();

    return new Response("Wrote to server", { status: 200 });
  },
};

TypeScript

index.ts

import net from "node:net";

const exampleIP = "127.0.0.1";

export default {
  async fetch(req): Promise<Response> {
    const socket = new net.Socket();
    socket.connect(4000, exampleIP, function () {
      console.log("Connected");
    });

    socket.write("Hello, Server!");
    socket.end();

    return new Response("Wrote to server", { status: 200 });
  },
} satisfies ExportedHandler;

Additionally, other APIs such as net.BlockList ↗ and net.SocketAddress ↗ are available.

Note that the net.Server ↗ class is not supported by Workers.

The full node:net API is documented in the Node.js documentation for node:net ↗.