🚀Multi-Chain Payment Gateway

A comprehensive multi-chain payment gateway supporting Ethereum, BSC, Arbitrum, Polygon, and Harmony with advanced dashboards, administrative controls, and easy-to-integrate client-side widgets.

✨ Features

Multi-Chain Support

• Ethereum Mainnet: Native ETH, WBTC, WETH, USDT, DAI, USDC

• Binance Smart Chain: Native BNB, BTCB, USDT, DAI, USDC

• Arbitrum One: Native ETH, WBTC, WETH, USDT, DAI, USDC

• Polygon: Native MATIC, WBTC, WETH, USDT, DAI, USDC

• Harmony One: Native ONE, ETH, BTC, USDT, DAI, USDC

Comprehensive Dashboards

• Main Dashboard: Real-time overview of all chains, payments, and system health

• Administrative Dashboard: Complete configuration management for chains, widgets, and security

• Widget Management: Create, configure, and manage client-side payment widgets

• Multi-Chain Monitoring: Live status of all blockchain networks with latency and block data

Client-Side Widgets

• Easy Integration: Single script tag deployment

• Customizable Themes: Light and dark mode support

• Multi-Chain Selection: Users can choose their preferred blockchain

• Payment Calculation: Real-time amount calculation with discount support

• Event-Driven: Custom events for seamless integration with existing applications

Advanced Features

• Discount System: Configurable discount codes and percentages

• Transaction Verification: Automatic blockchain verification of payments

• Security: Rate limiting, CORS protection, and secure headers

• RESTful API: Clean and well-documented endpoints

• Real-time Updates: Auto-refreshing dashboards with live data

🛠️ Installation

1. Clone the repository

   git clone https://github.com/Whostler/paymentGateway.git
   cd paymentGateway

2. Install dependencies

   npm install

3. Set up environment variables

   cp .env.example .env
   # Edit .env with your configuration

4. Start the server

   # Development mode
   npm run dev
   
   # Production mode
   npm start

🔧 Configuration

Environment Variables

# Server Configuration
PORT=3000
NODE_ENV=development

# Multi-Chain RPC Endpoints
ETH_RPC_URL=https://mainnet.infura.io/v3/YOUR_PROJECT_ID
BSC_RPC_URL=https://bsc-dataseed1.binance.org
ARB_RPC_URL=https://arb1.arbitrum.io/rpc
POLYGON_RPC_URL=https://polygon-rpc.com
HARMONY_RPC_URL=https://api.harmony.one

# Payment Settings
DEFAULT_DISCOUNT_PERCENT=0
MIN_PAYMENT_AMOUNT=1
MAX_PAYMENT_AMOUNT=1000000

Supported Blockchains

Blockchain	Native Token	Chain ID	Block Explorer
Ethereum	ETH	1	Etherscan
BSC	BNB	56	BSCScan
Arbitrum	ETH	42161	Arbiscan

cd frontend pnpm install pnpm dev

Backend:

pnpm install pnpm dev

When developing locally run the backend at :3000 and the frontend Vite dev server (default :5173) or use pnpm run frontend:dev from project root which proxies /api to the backend.

| Harmony | ONE | 1666600000 | Harmony Explorer |

📊 Dashboards

Main Dashboard

Access the comprehensive dashboard at http://localhost:3000/dashboard.html

Features:

• System Overview: Real-time health, uptime, and environment status

• Multi-Chain Status: Connected chains, latency, and network health

• Payment Statistics: Transaction volume, success rates, and analytics

• Widget Analytics: Integration health and usage metrics

• Blockchain Networks: Live status of all supported chains

Administrative Dashboard

Access admin controls at http://localhost:3000/admin-dashboard.html

Features:

• Chain Management: Enable/disable chains, configure settings

• System Configuration: Payment settings, security controls

• Widget Management: Create, configure, and delete widgets

• Security Settings: Rate limiting, CORS configuration

🔌 API Endpoints

Base URL

http://localhost:3000/api

Dashboard Endpoints

Get Dashboard Data

GET /dashboard/data

Get Multi-Chain Statistics

GET /dashboard/multichain

Get System Health

GET /dashboard/health

Admin Endpoints

Get Configuration

GET /admin/config

Update Configuration

PUT /admin/config

Chain Management

GET /admin/chains
PUT /admin/chains/:chainName/toggle
PUT /admin/chains/:chainName/settings

Widget Endpoints

Generate Widget

POST /widgets/generate

Request Body:

{
  "type": "payment",
  "theme": "light",
  "chains": ["ethereum", "bsc"],
  "domain": "yourdomain.com"
}

List Widgets

GET /widgets/list

Serve Widget Script

GET /widgets/:widgetId.js

🔗 Widget Integration

Quick Integration

Add this script tag to your website:

<script src="http://localhost:3000/widgets/WIDGET_ID.js"></script>

Custom Container

Specify a custom container for the widget:

<div id="my-payment-widget"></div>
<script src="http://localhost:3000/widgets/WIDGET_ID.js"></script>
<script>
  PaymentWidget.init('my-payment-widget');
</script>

Event Handling

Listen for payment events:

window.addEventListener('paymentRequested', (event) => {
  const { widgetId, token, amount, chain } = event.detail;
  // Handle payment processing
  console.log('Payment requested:', event.detail);
});

Widget Configuration

Widgets support various configuration options:

• Type: payment, calculator

• Theme: light, dark

• Chains: Array of supported chains

• Customization: Colors, branding, styling

🧪 Testing

Run the test suite:

npm test

Test specific modules:

npm run test:unit
npm run test:integration
npm run test:e2e

🔐 Security Features

• Multi-Chain Security: Secure transaction verification across all chains

• Rate Limiting: Protects against abuse and DDoS attacks

• CORS Protection: Configurable origin whitelist

• Security Headers: Comprehensive security header configuration

• Input Validation: Strict validation of all requests

• Environment Isolation: Separate configurations for development and production

🚀 Deployment

Production Setup

1. Set environment to production

   export NODE_ENV=production

2. Configure production RPC endpoints

   • Set up reliable RPC endpoints for all chains

   • Configure proper rate limits and security settings

   • Set secure JWT secrets and encryption keys

3. Use process manager

   npm install -g pm2
   pm2 start api/server.js --name "payment-gateway"

Docker Deployment

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

🤝 Integration Examples

E-commerce Integration

// Initialize payment widget
const widget = new PaymentWidget({
  type: 'payment',
  theme: 'light',
  chains: ['ethereum', 'polygon'],
  customization: {
    colors: {
      primary: '#your-brand-color'
    }
  }
});

// Handle payment completion
window.addEventListener('paymentRequested', async (event) => {
  const { token, amount, chain } = event.detail;
  
  // Process payment with your backend
  const result = await processPayment({
    token,
    amount,
    chain,
    orderId: 'your-order-id'
  });
  
  if (result.success) {
    // Redirect to success page
    window.location.href = '/payment-success';
  }
});

Subscription Service Integration

// For recurring payments
const subscriptionWidget = new PaymentWidget({
  type: 'subscription',
  chains: ['polygon', 'bsc'], // Lower gas fees
  recurring: {
    interval: 'monthly',
    amount: 9.99
  }
});

📈 Monitoring and Analytics

The gateway provides comprehensive monitoring:

• Real-time Chain Status: Monitor all blockchain networks

• Payment Analytics: Track transaction volume and success rates

• Widget Performance: Monitor widget usage across domains

• System Health: CPU, memory, and network monitoring

• Custom Metrics: Configurable business metrics

🆘 Support and Documentation

• API Documentation: Available at /api/docs (when enabled)

• Widget Documentation: See /widget-demo.html for examples

• Configuration Guide: Detailed in this README

• Troubleshooting: Check logs and health endpoints

📝 License

MIT License - see LICENSE file for details.

🤝 Contributing

1. Fork the repository

2. Create a feature branch

3. Commit your changes

4. Push to the branch

5. Create a Pull Request

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Built with ❤️ for the multi-chain future