Vobiz WebRTC SDK for Flutter

Make and receive voice calls in your Flutter app using Vobiz — a SIP-based calling platform with WebRTC media.

  • 📞 Make outbound calls to phone numbers (PSTN)
  • 📲 Receive inbound calls automatically
  • 🎙️ Crystal clear audio via WebRTC
  • 🔌 Auto-reconnect on network issues
  • 📱 Works on Android & iOS

🚀 Quick Start (5 Minutes)

1. Install the SDK

flutter pub add vobiz_webrtc

2. Get Your Vobiz Credentials

  1. Log in to Vobiz Console
  2. Go to Voice → Endpoints
  3. Create or select an endpoint and copy:
    • Username (e.g., myendpoint123456789)
    • Password (from endpoint creation)

3. Wire Up the SDK

import 'package:vobiz_webrtc/vobiz_webrtc.dart';

// Create client
final client = VobizClient(
  config: SdkConfig(
    wsUrl: 'wss://registrar.vobiz.ai:5063/',
    sipServer: 'registrar.vobiz.ai',
    backendUrl: 'https://your-backend.example.com',
  ),
);

// Connect
await client.connect();

// Login
await client.login(
  username: 'your-endpoint-username',
  password: 'your-endpoint-password',
);

// Listen for calls
client.state.listen((state) {
  print('Call: ${state.call}');
});

// Make a call
await client.makeCall('+1234567890');

// Answer incoming call
await client.answer();

// Hang up
await client.hangup();

⚙️ Platform Setup

Android Setup

Add permissions to android/app/src/main/AndroidManifest.xml:

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

Request microphone permission at runtime:

import 'package:permission_handler/permission_handler.dart';

await Permission.microphone.request();

iOS Setup

Add to ios/Runner/Info.plist:

<key>NSMicrophoneUsageDescription</key>
<string>We need microphone access to make and receive calls</string>
<key>NSLocalNetworkUsageDescription</key>
<string>We need local network access for calling</string>

Request permissions:

import 'package:permission_handler/permission_handler.dart';

await Permission.microphone.request();

📖 Full Guide

1. Setup Backend

You need an Answer URL server. See vobiz-rtc-demo for Node.js reference.

2. Connect to SIP

final client = VobizClient(
  config: SdkConfig(
    wsUrl: 'wss://registrar.vobiz.ai:5063/',
    sipServer: 'registrar.vobiz.ai',
    backendUrl: 'https://your-backend.example.com',
  ),
);

await client.connect();

3. Login with Credentials

await client.login(
  username: 'your-endpoint-username',
  password: 'your-endpoint-password',
);

4. Make Outbound Calls

await client.makeCall('+1234567890');

// Listen for state changes
client.state.listen((state) {
  if (state.call == CallState.inCall) {
    print('Call connected!');
  }
});

5. Handle Inbound Calls

client.state.listen((state) {
  if (state.call == CallState.incoming) {
    print('Incoming from: ${state.callerId}');
    // Show accept/reject UI
  }
});

// Accept
await client.answer();

// Or reject
await client.reject();

6. Call Control

// Mute microphone
await client.setMuted(true);

// Unmute
await client.setMuted(false);

// End call
await client.hangup();

🔗 Answer URL Contract

Your backend must handle /answer endpoint:

Outbound (SDK initiates):

<?xml version="1.0"?>
<Response>
  <Dial callerId="+1xxxxxxxxxx">
    <Number>+1234567890</Number>
  </Dial>
</Response>

Inbound (PSTN calls your number):

<?xml version="1.0"?>
<Response>
  <Dial>
    <User>sip:your-endpoint@registrar.vobiz.ai</User>
  </Dial>
</Response>

See vobiz-rtc-demo/server.js for full implementation.

📚 API Reference

VobizClient

// Connection
Future<void> connect()
Future<void> login(String username, String password)
Future<void> disconnect()

// Outbound
Future<void> makeCall(String destination)

// Inbound
Future<void> answer()
Future<void> reject()

// Control
Future<void> hangup()
Future<void> setMuted(bool muted)

// State
Stream<VobizState> get state

VobizState

ClientConnectionState connection   // disconnected/connecting/connected
RegistrationState registration     // unregistered/registering/registered/failed
CallState call                     // idle/calling/incoming/inCall/ended
String? callerId                   // Incoming caller ID
String? errorMessage               // Error if any
bool isMuted                       // Microphone muted?

📄 Features

  • ✅ SIP registration with digest auth
  • ✅ Outbound calls to PSTN numbers
  • ✅ Inbound call detection
  • ✅ WebRTC audio
  • ✅ Mute/Unmute
  • ✅ Hold/Resume
  • ✅ Blind transfer
  • ✅ Three-way conference
  • ✅ Auto-reconnect

🐛 Troubleshooting

Issue Solution
"SIP socket closed" Check internet, verify credentials, endpoint must be Active
No audio Use physical device, not emulator; grant microphone permissions
Inbound calls don't arrive Verify app is registered; check Answer URL is correct in Vobiz Console

📦 Requirements

  • Flutter 3.19.0+
  • Dart 3.3.0+
  • Android 5.0+ or iOS 11.0+

📚 Resources

📄 License

MIT License — See LICENSE file

Support

Libraries

vobiz_webrtc