@rcompat/net

TCP and unix socket connections for JavaScript runtimes.

What is @rcompat/net?

A cross-runtime module for opening raw TCP and unix domain socket connections, backed by native Web Streams. Works consistently across Node, Deno, and Bun — each runtime uses its own native socket implementation under the hood (node:net, Bun.connect, Deno.connect), so there's no shared polyfill or compatibility shim sitting between you and the runtime.

Installation

npm install @rcompat/net

pnpm add @rcompat/net

yarn add @rcompat/net

bun add @rcompat/net

Usage

Opening a connection

import net from "@rcompat/net";

// unix domain socket
const socket = await net.open({ path: "/var/run/example.sock" });

// tcp
const socket = await net.open({ host: "127.0.0.1", port: 9999 });

Writing and reading

import net from "@rcompat/net";

const socket = await net.open({ path: "/var/run/example.sock" });

await socket.write("ping\n");
await socket.end(); // half-close — stop writing, keep reading

const response = await socket.text(); // drains readable to a string

Streaming chunks

import net from "@rcompat/net";

const socket = await net.open({ host: "127.0.0.1", port: 9999 });

await socket.write("subscribe\n");

for await (const chunk of socket) {
  console.log(new TextDecoder().decode(chunk));
}

Closing

import net from "@rcompat/net";

const socket = await net.open({ path: "/var/run/example.sock" });

await socket.write("hello\n");
await socket.close(); // closes both write and read sides

end() only closes the write side (sends FIN, server can still respond) — use it when you expect a response after writing. close() tears down both sides — use it when you're done with the connection entirely.

API Reference

net

function open(options: NetOptions): Promise<Socket>;

NetOptions

type TCPOptions = { host: string; port: number };
type UnixOptions = { path: string };
type NetOptions = TCPOptions | UnixOptions;

A plain discriminated union — pass { host, port } for TCP or { path } for a unix domain socket. No separate transport tag needed.

Socket

class Socket {
  readable: ReadableStream<Uint8Array>;
  writable: WritableStream<Uint8Array>;

  write(data: string | Uint8Array): Promise<void>;
  end(): Promise<void>;
  close(): Promise<void>;
  text(): Promise<string>;

  [Symbol.asyncIterator](): AsyncIterator<Uint8Array>;
}

Socket isn't constructed directly — instances only come from net.open(). The type is exported for annotating function parameters and return types.

Examples

Talking to a control-plane socket (e.g. HAProxy)

import net from "@rcompat/net";

async function command(input) {
  const socket = await net.open({ path: "/var/run/haproxy.sock" });
  await socket.write(`${input}\n`);
  await socket.end();
  return socket.text();
}

await command("show info");

Simple TCP request/response

import net from "@rcompat/net";

const socket = await net.open({ host: "api.internal", port: 8080 });
await socket.write("STATUS\n");
await socket.end();

console.log(await socket.text());

Cross-Runtime Compatibility

| Runtime | Supported | | ------- | --------- | | Node.js | ✓ | | Deno | ✓ | | Bun | ✓ |

No configuration required — @rcompat/net resolves the correct native implementation per runtime via package export conditions.

License

MIT

Contributing

See CONTRIBUTING.md in the repository root.