hotspot_connection

A Flutter plugin for local network peer-to-peer (P2P) discovery and communication. This plugin uses native Network Service Discovery (NSD on Android, Bonjour/NetService on iOS) to find nearby devices on the same Wi-Fi network and establishes direct TCP socket connections for real-time data broadcasting and chat rooms.

Features

Broadcast Presence: Let other devices on the local network find you.
Discover Devices: Scan the network for other devices broadcasting their presence.
Create P2P Rooms: Host a session and connect with multiple selected devices.
Real-time Messaging: Send and receive text payloads natively across connected TCP sockets.
Cross-Platform: Supports both Android and iOS with native APIs.
Strongly Typed: Clean, strongly-typed domain models matching the underlying native platform responses.

Platform Setup

Android

Add the following permissions to your android/src/main/AndroidManifest.xml:

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

iOS

Add the following keys to your ios/Runner/Info.plist:

<key>NSLocalNetworkUsageDescription</key>
<string>We need to discover nearby devices.</string>
<key>NSBonjourServices</key>
<array>
    <string>_hotspotchat._tcp</string>
</array>

Usage

1. Initialize Plugin

import 'package:hotspot_connection/hotspot_connection.dart';

final hotspot = HotspotConnection();

2. Joiner: Broadcast Presence

To allow the host to find you, start broadcasting your username:

await hotspot.startBroadcasting("John Doe");

// Listen for connection events when the host creates the room
hotspot.roomEvents.listen((event) {
  if (event is PeerJoinedEvent) {
    print("Joined the room! Connected to: ${event.peer.name}");
  }
});

3. Host: Discover Devices

Start looking for broadcasting devices:

await hotspot.startDiscovery();

// Listen to the discovery stream to see devices (Peer objects) as they are found
hotspot.discoveryEvents.listen((Peer device) {
  print("Found device: ${device.name} (ID: ${device.id})");
});

4. Host: Create a Room

Once you have collected the IDs of the discovered devices, select the ones you want to connect to:

await hotspot.stopDiscovery(); // Good practice to stop scanning before connecting
final result = await hotspot.createRoom(["uuid-device-1", "uuid-device-2"]);

if (result.isSuccess) {
  print("Room created successfully!");
} else {
  print("Failed to connect to: ${result.failedConnections}");
}

5. Send and Receive Messages

Once connected, both Host and Joiners can listen to and send messages using the typed event stream:

Listen for messages:

hotspot.roomEvents.listen((event) {
  if (event is MessageReceivedEvent) {
    print("Received from ${event.peerId}: ${event.message}");
  } else if (event is PeerLeftEvent) {
    print("User ${event.peerId} disconnected.");
  } else if (event is PeerJoinedEvent) {
    print("User ${event.peer.name} joined.");
  }
});

Send a message:

await hotspot.sendMessage("Hello everyone!");

Example

Check the example/ folder for a complete working chat application implementing host and join features using the strongly typed system.