webrtc_dart #

Server-side WebRTC in pure Dart. Build SFUs, recording servers, and media pipelines.

What is webrtc_dart? #

A server-side WebRTC library for Dart, similar to Pion (Go), aiortc (Python), and werift (TypeScript).

Use cases:

• SFU (Selective Forwarding Unit)
• Recording servers (WebM/MP4)
• Media processing pipelines
• DataChannel messaging backends
• WebRTC-to-other-protocol bridges

Features #

Server-Side vs Browser WebRTC #

webrtc_dart handles transport, not media capture/playback:

Installation #

dependencies:
  webrtc_dart: ^0.25.0

Quick Start #

DataChannel #

import 'package:webrtc_dart/webrtc_dart.dart';

void main() async {
  final pc = RTCPeerConnection(RtcConfiguration(
    iceServers: [IceServer(urls: ['stun:stun.l.google.com:19302'])],
  ));

  final channel = pc.createDataChannel('chat');

  channel.onOpen.listen((_) => channel.sendString('Hello!'));
  channel.onMessage.listen((msg) => print('Received: $msg'));

  pc.onIceCandidate.listen((candidate) {
    // Send to remote peer via signaling
  });

  final offer = await pc.createOffer();
  await pc.setLocalDescription(offer);
}

Receiving Media (SFU Pattern) #

final pc = RTCPeerConnection();

pc.onTrack.listen((transceiver) {
  // Access raw RTP packets
  transceiver.receiver.onRtp = (packet) {
    // Forward to other peers, record, or process
  };
});

Recording to WebM #

// Record received media to file
final recorder = MediaRecorder(
  tracks: [videoTrack, audioTrack],
  path: 'output.webm',
);
await recorder.start();
// ... receive media ...
await recorder.stop();

API Overview #

Browser Interop #

Tested with Chrome, Firefox, and Safari via automated Playwright tests.

Examples #

See example/ for the original examples ported from werift:

• datachannel/ - Data channel patterns
• mediachannel/ - SFU patterns (sendonly, recvonly, sendrecv)
• save_to_disk/ - Recording to WebM/MP4
• mediachannel/pubsub/ - Multi-peer SFU

To see additional examples comparing how to implement in either werift or webrtc_dart see WebRTC Examples

Performance #

Comparison: webrtc_dart v0.25.0 vs werift v0.22.2

Binary parsing operations are faster than werift (TypeScript). With native OpenSSL, SRTP is now competitive.

*ICE parsing uses Dart regex vs werift's native string ops. **With native OpenSSL (was 30x slower with pure Dart).

Run benchmarks: ./benchmark/run_perf_tests.sh

Native Crypto Optimization #

SRTP encryption/decryption automatically uses native OpenSSL when available (~16x faster), falling back to pure Dart for maximum portability.

// Check what crypto is being used
print(CryptoConfig.description);  // "Native (OpenSSL: /path)" or "Dart (pure)"

// Force pure Dart (disable native)
CryptoConfig.useNative = false;

// Or via environment variable:
// WEBRTC_NATIVE_CRYPTO=0 dart run your_app.dart

No configuration needed - native crypto is used automatically when available.

Test Coverage #

2661 tests passing (including 41 performance regression tests) with browser interop validation.

dart test                        # Run all tests
dart test --exclude-tags=slow    # Fast tests only (~7s)
dart test --tags=slow            # Slow/integration tests
dart test test/performance/      # Performance regression tests

Acknowledgments #

Port of werift-webrtc by Yuki Shindo.

License #

MIT