dns-sd

A powerful, cross-platform DNS-SD (Zeroconf/Bonjour/Avahi) library for Node.js, built with Rust.

dns-sd provides a unified API for discovering and advertising services on the local network. It intelligently selects the best available backend:

* Native: Uses the system's native DNS-SD implementation (Avahi on Linux, Bonjour on macOS/Windows) for optimal performance and compatibility.
* Fallback: Automatically degrades to a pure Rust implementation (mdns-sd) if the native service is unavailable.

Features

* 🚀 High Performance: Native bindings via Neon for low overhead.
* 🔄 Dual Backend: Robust fallback mechanism ensures your app works everywhere.
* 📦 Zero Configuration: Works out of the box without complex setup.
* 📡 Discovery & Advertising: Support for both browsing and publishing services.
* 📝 TypeScript Support: First-class types included.

Installation

``bash
npm install dns-sd
`

Prebuilt binaries are available for major platforms:
* Windows (x64, arm64)
* macOS (x64, arm64)
* Linux (x64, arm64)

Usage

$3

Browsing for services is simple. Use the search method to start listening for services of a specific type.

`typescript
import DnsSd, { Service } from 'dns-sd';

// Search for HTTP services
const browser = DnsSd.search('_http._tcp');

browser.on('serviceFound', (service: Service) => {
console.log('Found service:', service.name);
console.log('IP Addresses:', service.addresses);
console.log('Port:', service.port);
if (service.txt) {
console.log('TXT Records:', service.txt);
}
});

browser.on('serviceLost', (service: Service) => {
console.log('Lost service:', service.name);
});

browser.on('error', (err) => {
console.error('Browser error:', err);
});

// Stop browsing after 30 seconds
setTimeout(() => {
browser.stop();
}, 30000);
`

$3

Publish your own service to the network using advertise.

`typescript
import DnsSd, { DnsSdAdvertisement } from 'dns-sd';

const ad = DnsSd.advertise({
name: 'My Cool Service',
type: '_http._tcp',
port: 8080,
txt: {
version: '1.0.0',
path: '/api'
}
});

ad.on('registered', (name) => {
console.log(Service registered successfully as "${name}");
});

ad.on('error', (err) => {
console.error('Advertisement error:', err);
});

// Stop advertising when closing
// ad.stop();
`

$3

You can check which backend is currently active (dependent on system availability).

`typescript
import DnsSd from 'dns-sd';

console.log('Current Backend:', DnsSd.getBackendInfo());
// Outputs: "bonjour", "native" (Avahi), or "mdns-sd"
`

API Reference

$3

The main entry point.

* static search(serviceType: string): DnsSdBrowse: Start a browser for the given service type (e.g., _http._tcp).
* static advertise(options: AdvertiseOptions): DnsSdAdvertisement: Start advertising a service.
* static getBackendInfo(): string: Returns the name of the active backend.

$3

Emits events for service discovery.

Events:
* 'serviceFound': Emitted when a service is discovered or updated. Payload: Service.
* 'serviceLost': Emitted when a service goes offline. Payload: Service.
* 'error': Emitted on failure. Payload: Error.

Methods:
* stop(): Stops the browser.

$3

Manages a published service.

Events:
* 'registered': Emitted when the service is successfully registered with the daemon. Payload: string (registered name).
* 'error': Emitted on failure. Payload: Error.

Methods:
* stop(): Stops advertising.

$3

#### Service
`typescript
interface Service {
name: string;
type: string;
domain: string;
hostName: string;
addresses: string[]; // IPv4 and IPv6 addresses
port: number;
txt?: Record;
ttl?: number;
}
`

#### AdvertiseOptions
`typescript
interface AdvertiseOptions {
name: string;
type: string;
domain?: string;
hostName?: string;
port: number;
txt?: Record;
}
`

Contributing

This project uses cargo for the Rust backend and npm for the Node.js frontend.

1. Install Dependencies: npm install
2. Build: npm run build
3. Test: npm test`

Licensed under MIT.

---

Built and maintained by BRICKS.