Scatty

A sensor-aware AI assistant for Android, inspired by Reachy Mini. Scatty uses your phone's microphone and camera to have natural conversations powered by Google Gemini.

Features

• Voice input with on-device speech recognition
• Streaming AI responses from Gemini
• Text-to-speech output
• Animated avatar with state-driven expressions
• Conversation history
• Session management
• Configurable server URL

Prerequisites

• Node.js 18+
• npm 9+
• Android Studio (for Android emulator) or physical Android device
• Expo Go app (for quick testing) or development build
• Google Gemini API key

Getting Started

1. Install Dependencies

npm install

2. Build Shared Types

npm run build:shared

3. Configure Server

cd apps/server
cp .env.example .env

Edit .env and add your Gemini API key:

GEMINI_API_KEY=your_api_key_here
PORT=3001

Get a free API key at: https://aistudio.google.com/apikey

4. Start the Server

npm run server

5. Start the Mobile App

In a new terminal:

npm run mobile

Then press:

• a - Open on Android emulator
• i - Open on iOS simulator (Mac only)
• Scan QR code with Expo Go app on physical device

Note: Voice recognition requires a physical device or properly configured emulator with microphone access.

Testing on Physical Device

1. Find your computer's local IP:

   • Mac/Linux: ifconfig | grep "inet "
   • Windows: ipconfig

2. Start the server (it binds to all interfaces)

3. In the Scatty app, tap the Settings icon (top-left)

4. Change the server URL to: http://YOUR_IP:3001

5. Tap Save & Reconnect

Building for Production

EAS Build (Android APK)

EAS builds must be run from the mobile app directory (not the monorepo root):

cd apps/mobile
eas build --platform android --profile preview

See Deployment Guide for full instructions.

Documentation

• Architecture - System design and component overview
• Deployment - Production deployment guides

Troubleshooting

"Connection failed" error

• Make sure the server is running
• Check that your device can reach the server IP
• Verify firewall isn't blocking port 3001

Voice recognition not working

• Use a physical device (emulators have limited mic support)
• Check microphone permissions in device settings
• Try the "Type" button as fallback

Metro bundler errors

cd apps/mobile
npx expo start --clear

Monorepo dependency issues

rm -rf node_modules apps/*/node_modules packages/*/node_modules
npm install
npm run build:shared

License

MIT