RunAnywhere React Native Starter App

February 14, 2026 · View on GitHub

A comprehensive starter app demonstrating the capabilities of the RunAnywhere SDK - a privacy-first, on-device AI SDK for React Native.

✨ Features

This starter app showcases four main capabilities of the RunAnywhere SDK:

💬 Chat (LLM Text Generation)

Streaming text generation with token-by-token output
Performance metrics (tokens/second, total tokens)
Cancel generation mid-stream
Suggested prompts for quick testing
Beautiful chat UI with message bubbles

🎤 Speech-to-Text (STT)

Real-time audio recording
On-device transcription using Whisper models
Audio level visualization
Transcription history
Privacy-first: all processing happens on device

🔊 Text-to-Speech (TTS)

Neural voice synthesis with Piper TTS
Adjustable speech rate (0.5x - 2.0x)
Sample texts for quick testing
Audio playback controls
High-quality, natural-sounding voices

✨ Voice Pipeline (Voice Agent)

Full voice assistant experience
Seamless integration: Speak → Transcribe → Generate → Speak
Real-time status updates
Conversation history
Complete end-to-end voice interaction

📦 SDK Packages Used

This app uses three RunAnywhere packages:

Package	Purpose	NPM
`@runanywhere/core`	Core SDK with infrastructure	View on NPM
`@runanywhere/llamacpp`	LLM backend (LlamaCpp)	View on NPM
`@runanywhere/onnx`	STT/TTS/VAD backend (ONNX)	View on NPM

🚀 Getting Started

Quick Start

# Clone and install
git clone https://github.com/RunanywhereAI/react-native-starter-app.git
cd react-native-starter-app
npm install

# iOS (requires pod install first)
cd ios && pod install && cd ..
npx react-native run-ios

# Android (no additional setup needed)
npx react-native run-android

Prerequisites

Node.js 18 or higher
React Native CLI development environment (setup guide)
iOS: Xcode 14+, CocoaPods, macOS
Android:
- Android Studio
- JDK 17+
- Android SDK 36 (compileSdk)
- NDK 27.1.12297006 (install via Android Studio → SDK Manager → SDK Tools → NDK)
- Build Tools 36.0.0
Physical device recommended for best performance (AI models run slowly on simulators)

Installation

Clone the repository

git clone https://github.com/RunanywhereAI/react-native-starter-app.git
cd react-native-starter-app

Install dependencies
```
npm install
```
Note: This runs patch-package automatically via postinstall to apply necessary compatibility fixes.
iOS Setup
```
cd ios
pod install
cd ..
```
Known Issue (RN 0.83): The @runanywhere SDK packages use podspecPath in their React Native config, which the RN 0.83 CLI no longer allows. To work around this, automaticPodsInstallation is set to false in react-native.config.js. This means you must always run pod install manually (as shown above) before building for iOS. You may see warnings about podspecPath when running run-ios — these are harmless and can be ignored. This will be fixed in a future SDK release.
Android Setup (verify your environment)

No additional setup is needed if you have Android Studio installed with the required SDK components. To verify:
```
# Check that ANDROID_HOME is set (should point to your Android SDK)
echo $ANDROID_HOME
# Expected: /Users/<username>/Library/Android/sdk (macOS) or similar

# Verify ADB is available
adb --version

# Check installed NDK versions (need 27.1.12297006)
ls $ANDROID_HOME/ndk/
```
If NDK 27 is missing, install it via Android Studio:
- Open Android Studio → Settings → SDK Manager → SDK Tools tab
- Check "Show Package Details" → expand "NDK (Side by side)"
- Select version 27.1.12297006 and click Apply

Run the app

For iOS:

npx react-native run-ios

For Android:

npx react-native run-android

Running with Two Terminals (Recommended)

For better control and visibility of logs, run Metro bundler and the app build in separate terminals:

Terminal 1 - Start Metro Bundler:

cd react-native-starter-app
npx react-native start

Wait until you see "Dev server ready", then in a second terminal:

Terminal 2 - Build & Run the App:

cd react-native-starter-app

# For iOS
npx react-native run-ios

# For Android
npx react-native run-android

Note: The first Android build takes 5-10 minutes as it compiles native C++ code. Subsequent builds are much faster.

Running on Physical Android Device

When running on a physical Android device, you need to set up port forwarding for the Metro bundler:

# Connect your device via USB and verify it's detected
adb devices

# Set up port forwarding (required for each USB session)
adb reverse tcp:8081 tcp:8081

# Start Metro bundler in one terminal
npx react-native start

# Run the app in another terminal
npx react-native run-android

Tip: If you see "Could not connect to development server", run adb reverse tcp:8081 tcp:8081 again.

iOS Permissions

The app requires microphone access. Permissions are already configured in ios/RunAnywhereStarter/Info.plist:

<key>NSMicrophoneUsageDescription</key>
<string>This app needs microphone access for speech recognition and voice agent features</string>
<key>NSSpeechRecognitionUsageDescription</key>
<string>This app uses on-device speech recognition to transcribe your voice</string>

Android Permissions

Required permissions are configured in 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.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

🏗️ Architecture

src/
├── App.tsx                      # Main app entry, SDK initialization
├── theme/
│   └── colors.ts               # Color palette and theme
├── services/
│   └── ModelService.tsx        # Model management (download, load, state)
├── components/
│   ├── FeatureCard.tsx         # Home screen feature cards
│   ├── ModelLoaderWidget.tsx   # Model download/load UI
│   ├── ChatMessageBubble.tsx   # Chat message UI
│   └── AudioVisualizer.tsx     # Audio level visualization
├── screens/
│   ├── HomeScreen.tsx          # Main navigation screen
│   ├── ChatScreen.tsx          # LLM chat interface
│   ├── SpeechToTextScreen.tsx  # STT interface
│   ├── TextToSpeechScreen.tsx  # TTS interface
│   └── VoicePipelineScreen.tsx # Voice agent interface
└── navigation/
    └── types.ts                # Navigation type definitions

🤖 Default Models

The app comes preconfigured with these models:

Model	Purpose	Size	Source
SmolLM2 360M Q8_0	Text generation	~400MB	HuggingFace
Sherpa ONNX Whisper Tiny EN	Speech recognition	~80MB	RunAnywhere
Piper TTS (US English)	Voice synthesis	~100MB	RunAnywhere

🎨 Customization

Using Different Models

You can modify src/services/ModelService.tsx to use different models:

// LLM Model - Example with a larger model
await LlamaCpp.addModel({
  id: 'qwen2-1.5b-q4',
  name: 'Qwen2 1.5B Q4',
  url: 'https://huggingface.co/...',
  memoryRequirement: 1500000000,
});

// STT Model - Example with multilingual support
await Onnx.addModel({
  id: 'whisper-small-multi',
  name: 'Whisper Small Multilingual',
  url: 'https://...',
  modality: ModelCategory.speechRecognition,
});

Theming

The app uses a custom dark theme defined in src/theme/colors.ts. You can customize:

export const AppColors = {
  primaryDark: '#0A0E1A',
  accentCyan: '#00D9FF',
  accentViolet: '#8B5CF6',
  // ... more colors
};

🔒 Privacy

All AI processing happens on-device. No data is sent to external servers. The models are downloaded once and stored locally on the device.

✅ No internet required after model download
✅ All inference runs locally
✅ Your conversations never leave your device
✅ No API keys or cloud services needed

🐛 Troubleshooting

"Could not connect to development server" (Android)

This happens on physical Android devices because they can't reach localhost on your computer.

# Set up port forwarding
adb reverse tcp:8081 tcp:8081

# Verify Metro is running
curl http://localhost:8081/status  # Should return "packager-status:running"

CMake Error: "add_subdirectory given source which is not an existing directory"

This happens when codegen hasn't run yet. Simply run the build again:

cd android && ./gradlew assembleDebug

The second run will succeed as codegen completes.

Models not downloading

Check your internet connection
Ensure sufficient storage space (models can be 100MB-1GB)
Check iOS/Android permissions
Clear app data and try again

Microphone not working

Grant microphone permission in device settings
Restart the app after granting permission
On Android, check if permission is granted in AndroidManifest.xml

Low performance

Smaller models (like SmolLM2 360M) work better on mobile devices
Close other apps to free up memory
Use quantized models (Q4/Q8) for better performance
Ensure you're running on a physical device (simulators are slow)

Build errors

Clear cache: cd android && ./gradlew clean or cd ios && rm -rf Pods Podfile.lock
Reinstall dependencies: rm -rf node_modules && npm install
For iOS: cd ios && pod install --repo-update
For Android: Delete android/app/build and android/.gradle folders, then rebuild

Android NDK not found

If you see errors about NDK not found:

# Check if NDK 27 is installed
ls ~/Library/Android/sdk/ndk/

# If missing, install via Android Studio SDK Manager or:
sdkmanager "ndk;27.1.12297006"

Android SDK location not found

Ensure local.properties exists in the android/ folder with your SDK path:

sdk.dir=/Users/<username>/Library/Android/sdk

This file is auto-generated when you open the project in Android Studio.

Patches not applied

If you see build errors related to react-native-nitro-modules, ensure patches are applied:

npx patch-package

This should run automatically via postinstall, but you can run it manually if needed.

GitHub Issues: Report bugs
Email: san@runanywhere.ai
Documentation: runanywhere.ai
Discord: Join our community

🎯 Next Steps

Explore the code: Check out each screen to understand how the SDK works
Try different models: Swap in your own models to see what works best
Build your app: Use this as a foundation for your own AI-powered app
Share feedback: Let us know what you think and what features you'd like to see

⭐ Acknowledgments

Built with:

Special thanks to the open-source community and the RunAnywhere team!

Made with ❤️ by the RunAnywhere team