Client (Flutter)

Needs a running Server

The client does no transcription alone. You must point it to a running Server (ws://YOUR_SERVER_IP:8765). Start one first — see Server Guide or Quick Start.

Options — pick one

Web App (no install)

Nothing to install — runs in any modern browser (desktop or mobile).

1. Start your server (Docker / binary / cargo)
2. Open Web App — https://lutgaru.github.io/Sinsajo/app/
3. Settings → set Server IP (e.g. 192.168.1.100:8765) → tap mic → speak

Microphone on Web

Browsers require HTTPS for getUserMedia. GitHub Pages provides it. If you self-host the Web App elsewhere, ensure TLS. onnxruntime-web WASM needs correct MIME and COOP/COEP headers if you customize hosting.

The Web App on GitHub Pages is built from sinsajo_client via:

flutter build web --release --base-href /Sinsajo/app/

In CI it is merged into docs-site/dist/app/ for a single Pages deploy. Preview locally:

cd docs-site && npm run build
# PowerShell: Copy-Item -Recurse -Force ../sinsajo_client/build/web/* dist/app/
# Bash: cp -r ../sinsajo_client/build/web/* dist/app/

Android APK

For Android phones/tablets — distribute via link or QR without recompiling.

Install:

• Download app-release.apk from client-latest
• Enable Install unknown apps on Android → install → open → Settings → set server IP

Build yourself (optional):

build/app/outputs/flutter-apk/app-release.apk

cd sinsajo_client
flutter pub get
flutter build apk --release

Built automatically on every client/v* tag via GitHub Actions. Do not commit APKs to git — link to the Release or generate a QR.

Minimum: Android device meeting Flutter 3.x requirements.

Build from source

For any platform meeting client requirements (Flutter 3.x): Android, iOS, Linux, macOS, Windows, Web.

git clone https://github.com/lutgaru/Sinsajo.git
cd Sinsajo/sinsajo_client
flutter pub get
flutter run                  # runs on connected device/emulator/desktop
# or target a platform:
flutter build apk --release
flutter build ios --release
flutter build linux --release
flutter build web --release --base-href /Sinsajo/app/

Configure the default server URL in code (overridden in Settings UI):

lib/providers/transcription_provider.dart

const String kWsUrl = 'ws://192.168.1.100:8765';

Other in-app Settings: microphone gain, audio source, save_audio + format wav/ogg, target_language (enabled per model_info.languages from server).

Voice Activity Detection

In lib/services/audio_service.dart:

await _vadHandler.startListening(
  model: 'v5',
  frameSamples: 512,
  positiveSpeechThreshold: 0.5,
  negativeSpeechThreshold: 0.35,
  redemptionFrames: 8,
  preSpeechPadFrames: 1,
  minSpeechFrames: 3,
);

Tuning:

• Lower positiveSpeechThreshold to 0.3 for quiet voices
• Lower negativeSpeechThreshold to 0.2 to keep segments longer
• Increase redemptionFrames to 12 to avoid cutting pauses
• Package: vad (pub.dev) — Silero VAD v5 via ONNX Runtime

State & Protocol

Riverpod 2.x manages WebSocket lifecycle and transcription state. Check transcription_provider.dart for transcription, partial, final and model_info handlers. See Protocol for the full WebSocket spec.

Choosing quickly

Web App

Fastest to try or share — no install, just a URL. Needs server IP reachable via ws/wss.

APK

Best for testers on Android — one file, no store. Share Release link/QR.

From source

For developers or other platforms (iOS/Desktop/Web) — compile with Flutter on any supported OS/arch.