| Active Chat | Floating Overlay | AI Suggestions |
|---|---|---|
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Replyfy is a native Android floating overlay that generates contextual AI responses directly over WhatsApp, Telegram, and SMS without app switching. Built with React Native, Kotlin Native Modules, and Google Gemini 2.5 Flash-Lite via a Node.js Express proxy.
- Context-Aware Floating Bubble: Uses AccessibilityService to display overlay only inside messaging applications.
- 7 Smart Tones: Gen Z, Sarcastic, Sweet, Professional, Decline, Quick Reply, and Playful (Rizz/Shayari).
- Multi-Language Support: Automatically detects English, Hindi, and Hinglish.
- Privacy First: Local regex sanitization blocks passwords, API keys (
sk-,ghp_,AIza), and tokens before sending requests. Zero database logging. - Quota & Anti-Crash Resilience: Exponential backoff (4s to 64s retry window) to handle free-tier API rate limits gracefully.
| Tone | Description | Languages |
|---|---|---|
| Gen Z | Internet slang and trending abbreviations | English, Hinglish |
| Sarcastic | Witty comebacks and dry humor | English, Hinglish |
| Sweet | Empathetic and warm responses | English, Hindi |
| Professional | Formal, polished, and courteous | English, Hindi |
| Decline | Polite refusals and boundary setting | English, Hindi |
| Quick | Ultra-short (1–5 words) | All |
| Playful | Flirty, poetic, Shayari, and rizz-style | English, Hinglish, Hindi |
| Layer | Technology |
|---|---|
| Frontend | React Native 0.73, TypeScript |
| Native Android | Kotlin (WindowManager, AccessibilityService) |
| Backend | Node.js 18+, Express.js |
| AI Engine | Google Gemini 2.5 Flash-Lite |
| Security | Helmet.js, express-rate-limit |
| Hosting | Render.com |
- Android Studio (SDK API 34+)
- Node.js 18+
- Free Gemini API key
cd backend
npm install
cp .env.example .env
# Set GEMINI_API_KEY in .env
npm run devcd AIKeyboardMobile
npm install
# Create android/local.properties with API_URL and API_KEY
npx react-native run-androidcd AIKeyboardMobile/android
./gradlew assembleReleaseOutput: AIKeyboardMobile/android/app/build/outputs/apk/release/app-release.apk
MIT License - Free to use, modify, and distribute.


