Notification Listener Backend

A Node.js Express server for receiving and storing Android notification data from the Notification Listener app.

Features

• ✅ Webhook Endpoint - Receives notification data via HTTP POST
• ✅ SQLite Database - Stores notifications and device information
• ✅ API Key Authentication - Optional security layer
• ✅ REST API - Query stored notifications and statistics
• ✅ Health Monitoring - Health check endpoint
• ✅ CORS Support - Cross-origin requests enabled
• ✅ Request Logging - Morgan HTTP request logger
• ✅ Security Headers - Helmet.js security middleware

Quick Start

1. Install Dependencies

cd backend
npm install

2. Configure Environment

Edit .env file:

PORT=3000
API_KEY=your-secret-api-key

3. Start Server

# Development (with auto-reload)
npm run dev

# Production
npm start

The server will start on http://localhost:3000

API Endpoints

Core Endpoints

Method	Endpoint	Description
POST	/webhook	Main notification receiver
POST	/test	Test endpoint
GET	/health	Health check

Data Endpoints

Method	Endpoint	Description
GET	/notifications	Get stored notifications
GET	/devices	Get registered devices
GET	/stats	Get statistics

Authentication

All endpoints (except /health) require the X-API-Key header if API_KEY is configured in .env.

curl -H "X-API-Key: your-secret-api-key" http://localhost:3000/notifications

Webhook Usage

Android App Configuration

1. Set Endpoint URL: http://your-server:3000/webhook
2. Set API Key: your-secret-api-key (optional)

Example Notification Payload

{
  "deviceId": "550e8400-e29b-41d4-a716-446655440000",
  "packageName": "id.dana",
  "appName": "DANA",
  "postedAt": "2025-09-01T14:30:24+07:00",
  "title": "Payment received",
  "text": "Anda menerima Rp 100.000",
  "amountDetected": "100000",
  "extras": {
    "android.title": "Payment received"
  }
}

Response Format

{
  "success": true,
  "message": "Notification received successfully",
  "id": 123,
  "timestamp": "2025-09-01T07:30:24.000Z"
}

API Examples

Get Recent Notifications

curl -H "X-API-Key: your-secret-api-key" \
  "http://localhost:3000/notifications?limit=10"

Get Device-Specific Notifications

curl -H "X-API-Key: your-secret-api-key" \
  "http://localhost:3000/notifications?device_id=550e8400-e29b-41d4-a716-446655440000"

Get Statistics

curl -H "X-API-Key: your-secret-api-key" \
  "http://localhost:3000/stats"

Database Schema

notifications table

CREATE TABLE notifications (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    device_id TEXT NOT NULL,
    package_name TEXT NOT NULL,
    app_name TEXT,
    posted_at TEXT,
    title TEXT,
    text TEXT,
    sub_text TEXT,
    big_text TEXT,
    channel_id TEXT,
    notification_id INTEGER,
    amount_detected TEXT,
    extras TEXT,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

devices table

CREATE TABLE devices (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    device_id TEXT UNIQUE NOT NULL,
    last_seen DATETIME DEFAULT CURRENT_TIMESTAMP,
    total_notifications INTEGER DEFAULT 0,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

Testing

Test the Webhook

curl -X POST "http://localhost:3000/test" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: your-secret-api-key" \
  -d '{
    "test": true,
    "message": "Test notification",
    "timestamp": "2025-09-01T07:30:24Z"
  }'

Health Check

curl http://localhost:3000/health

Production Deployment

Using PM2

npm install -g pm2
pm2 start server.js --name "notification-backend"
pm2 startup
pm2 save

Using Docker

FROM node:18-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]

Environment Variables

Variable	Description	Default
PORT	Server port	3000
API_KEY	API authentication key	your-secret-api-key
DB_PATH	SQLite database path	./notifications.db

Security

• Enable API key authentication in production
• Use HTTPS in production
• Consider rate limiting for high-traffic scenarios
• Regularly backup the SQLite database
• Monitor server logs for suspicious activity

Troubleshooting

Common Issues

1. Database locked error

   • Ensure only one server instance is running
   • Check file permissions for notifications.db

2. API key errors

   • Verify .env file configuration
   • Check X-API-Key header in requests

3. CORS issues

   • Modify CORS configuration in server.js
   • Check browser developer tools for CORS errors

Logs

Server logs include:

• HTTP request details (via Morgan)
• Database operations
• Error messages
• Notification processing info