sherpa-onnx/flutter-examples/hello_world

hello_world

A minimal Flutter example that displays sherpa-onnx version information.

How this demo was created

Step 1: Create the Flutter project

cd flutter-examples
flutter create --project-name hello_world --org com.k2fsa hello_world

Step 2: Add sherpa_onnx dependency

Edit pubspec.yaml, replace the dependencies: section with:

dependencies:
  flutter:
    sdk: flutter
  sherpa_onnx: ^1.13.4

Then run:

cd hello_world
flutter pub get

Step 3: Replace lib/main.dart

Replace the contents of lib/main.dart with:

import 'package:flutter/material.dart';
import 'package:sherpa_onnx/sherpa_onnx.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  initBindings();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'sherpa-onnx hello world',
      home: const VersionPage(),
    );
  }
}

class VersionPage extends StatelessWidget {
  const VersionPage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('sherpa-onnx hello world')),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text('sherpa-onnx version: ${getVersion()}'),
            Text('Git SHA1: ${getGitSha1()}'),
            Text('Git date: ${getGitDate()}'),
            Text('onnxruntime version: ${getOnnxruntimeVersion()}'),
          ],
        ),
      ),
    );
  }
}

Step 4: Run the app

flutter run

The app will display the sherpa-onnx version, git SHA1, git date, and onnxruntime version.

Platform notes

• macOS: Minimum deployment target is 10.15
• iOS: Minimum deployment target is 13.0
• Android: Minimum SDK 21 (default)
• Linux: x64 and aarch64 supported
• Windows: x64 supported

Building for specific platforms

# macOS
flutter build macos

# iOS (no codesign for CI)
flutter build ios --no-codesign

# Android
flutter build apk

# Linux
flutter build linux

# Windows
flutter build windows

Running on Web (Chrome)

cd flutter-examples/hello_world
flutter pub get
flutter run -d chrome

Build for deployment

flutter build web

The output is in build/web/. Serve it with any HTTP server:

cd build/web
python3 -m http.server 8080

Then start your browser and visit http://localhost:8080 .

Notes

• The web build uses WebAssembly (via Emscripten) to run the sherpa-onnx C API in the browser. No server-side processing is needed.
• The WASM binary is ~15-20MB as it includes all features (ASR, TTS, VAD, etc.)
• First load may take a few seconds while the WASM module is downloaded and compiled

Running on iOS simulator

Step 1: List available simulators

xcrun simctl list devices

Look for a booted simulator, e.g.:

iPhone 16 Plus (UUID) (Booted)

Step 2: Run on the simulator

flutter run -d <UUID>

For example:

flutter run -d 34FB0674-4ABA-4870-ABF2-D0D6E110A7C2

Troubleshooting

If you see ld: framework 'sherpa_onnx' not found, it means the Xcode project has stale Swift Package Manager (SPM) references. Remove them:

cd ios
# Remove SPM references from the Xcode project
# (edit Runner.xcodeproj/project.pbxproj to remove FlutterGeneratedPluginSwiftPackage entries)

Or regenerate the iOS project:

flutter clean
flutter pub get
flutter run -d <UUID>