🛰️ mdns_responder

A Flutter plugin for publishing mDNS (Multicast DNS) services on Android and iOS, with support for advanced features like TXT records, host addresses, subtypes, and libp2p compatibility.

✅ Supports NetService (Bonjour) on iOS

✅ Uses NsdManager on Android

✅ Compatible with libp2p, IPFS, and other P2P service discovery protocols

✨ Features

Publish mDNS services with:
Service name, type, and port
Host IP addresses (Android only)
TXT record attributes (key-value pairs)
Subtypes (Android 14+ only)
Network identifier (Android only)
Fully asynchronous Dart API
Platform channel implementation
Tested with dns-sd and avahi-browse

🚀 Getting Started

1. Add to pubspec.yaml

dependencies:
  mdns_responder:
    git:
    url: https://github.com/eelco2k/mdns_responder.git

2. Platform Setup

✅ Android

Add the following to your AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

Subtypes require Android 14+ (API 34).

✅ iOS

Add Bonjour service types to Info.plist:

<key>NSBonjourServices</key>
<array>
    <string>_p2p._udp</string>
</array>

✅ Usage

Import the plugin

import 'package:mdns_responder/mdns_responder.dart';
import 'package:mdns_responder/models/mdns_service.dart';

Publish a service

final service = MdnsService(
name: 'peer-abc123',
type: '_p2p._udp',
port: 4001,
hostAddresses: ['192.168.1.42'], // Android only
attributes: {
'id': 'QmPeerID',
'proto': 'libp2p',
},
subtypes: ['_libp2p'], // Android 14+ only
);
await MdnsResponder().publishService(service);

Stop the service

await MdnsResponder().stopService();

🧪 Testing

Unit tests

flutter test

Includes tests for:

MdnsService serialization
Mock platform interface
Method channel communication

Integration test (example app)

flutter drive \
--driver integration_test/driver.dart \
--target integration_test/mdns_test.dart

You can also test manually using dns-sd or avahi-browse on the same network.

🔍 Service Discovery

To verify your service is visible:

On macOS

dns-sd -B _p2p._udp

On Linux

avahi-browse -a

You should see your peer-abc123 service appear.

📦 API Reference

MdnsService Fields

Field	Type	Description
name	String	Instance name of the service
type	String	Service type (e.g. _http._tcp)
port	int	Port number
hostAddresses	List	IP addresses (Android only)
attributes	Map<String, String>?	TXT record key-value pairs
subtypes	List	Subtypes (Android 14+ only)
network	String?	Network ID (Android only)

🛠️ Roadmap

Windows / Linux support via FFI or CLI
libp2p TXT record helpers
Subtypes for iOS

👥 Contributing

Pull requests are welcome! Please include tests and follow the existing code style.