@momics/dns-sd

Discover and advertise services on the local network — the same technology as Bonjour and Zeroconf — through one identical browse / advertise API across Node.js, Deno and Tauri (desktop and mobile). Standards-compliant mDNS (RFC 1035 / 6762 / 6763), with a pure-TypeScript core and zero native dependencies.

Warning

Experimental. Largely AI-generated, lightly tested, not yet published, and not production-ready. Use at your own risk.

Packages

Package	Runtime	Install (once published)
@momics/dns-sd-shared	any	the pure-TS codec + mDNS engine (no I/O of its own)
@momics/dns-sd-node	Node.js	npm install @momics/dns-sd-node
@momics/dns-sd-deno	Deno	deno add jsr:@momics/dns-sd-deno
@momics/dns-sd-tauri	Tauri v2	npm install @momics/dns-sd-tauri

Pick the package for your runtime — they all re-export the same API; -shared is the foundation the others build on.

Support

Platform	Runtimes
Linux · macOS · Windows	Node.js · Deno · Tauri (desktop)
iOS · Android	Tauri

Node, Deno and Tauri desktop speak mDNS directly over UDP multicast; on mobile, Tauri defers to the OS resolver, which imposes a few limits — see the Tauri README.

Usage

npm install @momics/dns-sd-node

Advertise a service:

import { advertise, browse, close } from "@momics/dns-sd-node";

const handle = await advertise({
  service: {
    type: "http",
    protocol: "tcp",
    name: "My Web Server",
    port: 8080,
    txt: { path: "/api", secure: true },
  },
});

Browse for services — an async iterator of lifecycle events:

import { browse } from "@momics/dns-sd-node";

for await (const svc of browse({
  service: { type: "http", protocol: "tcp" },
  timeoutMs: 5000, // omit for a continuous browse
})) {
  switch (svc.kind) {
    case "found":    // discovered, host/port not resolved yet
      console.log("found", svc.name);
      break;
    case "resolved": // host and port known; addresses are best-effort
      console.log(`${svc.name} → ${svc.host}:${svc.port}`, svc.addresses, svc.txt);
      break;
    case "updated":  console.log("changed", svc.name); break;
    case "removed":  console.log("gone", svc.name); break;
  }
}

Clean up when you're done:

await handle.stop(); // send a goodbye and unregister
await close();       // tear down the shared socket

That's the whole surface — advertise, browse, close. It's identical on every runtime; only the import and setup differ:

• Deno — import from @momics/dns-sd-deno and run with deno run --unstable-net --allow-net --allow-sys.
• Tauri — import from @momics/dns-sd-tauri and register the tauri-plugin-dns-sd plugin in your Rust app first (see the Tauri README).

A found event always carries null host/port — narrow to resolved or updated before you connect.

TXT records use the RFC 6763 three-state model: true for a bare key, a value for key=value, and null for an empty key=. When advertising, values may be a string, Uint8Array, true, or null; discovered values come back as Uint8Array | true | null. Keys are validated when you advertise.

How it works

The mDNS protocol is implemented once, in pure TypeScript; each runtime plugs a thin network backend into that shared engine, so every package exposes the exact same API. You don't need the details to use the library — if you're curious or want to add a runtime, see docs/architecture.md.

Contributing

Build, test and release instructions live in CONTRIBUTING.md.

This repository is governed by a constitution — AGENTS.md — that defines what "done" means, freezes the public API, and lists the ratchets that keep the package converging to a small, battle-tested fixed point. docs/convergence.md explains the philosophy; docs/api-design.md and docs/testing-strategy.md cover the API bar and the testing approach.

License

Dual-licensed under Apache-2.0 or MIT, at your option.