CrossFlow USDC Bridge

A decentralized bridge for transferring USDC between Ethereum and Stellar networks, with integrated fiat on/off ramps for African currencies.

Features

• 🌉 CrossFlow USDC transfers between Ethereum and Stellar
• 💱 Fiat on/off ramps supporting multiple African currencies
• 📱 Mobile money and USSD integration
• 🔒 Secure wallet management
• 📊 Real-time transaction monitoring
• 💳 Multiple payment methods

Quick Start

# Install dependencies
npm install

# Start development server
npm run dev

# Build for production
npm run build

Environment Setup

Create a .env file with the following variables:

# Ethereum
ETHEREUM_PROVIDER=https://sepolia.infura.io/v3/YOUR_INFURA_PROJECT_ID
USDC_CONTRACT_ADDRESS=0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238

# Stellar
STELLAR_NETWORK=TESTNET
STELLAR_HORIZON=https://horizon-testnet.stellar.org
USDC_ISSUER=GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN

# APIs
FLUTTERWAVE_SECRET_KEY=YOUR_FLUTTERWAVE_KEY
AT_API_KEY=YOUR_AFRICASTALKING_KEY

Architecture

Backend Services

• Bridge Service: Manages CrossFlow transfers using Connext protocol
• Rate Service: Real-time exchange rates for African currencies
• Blockchain Services: Ethereum and Stellar transaction handling
• USSD Service: Mobile money integration via Africa's Talking

Frontend Components

• Wallet Dashboard: Balance management and network selection
• Bridge Interface: CrossFlow transfer initiation
• Transaction Monitor: Real-time status tracking
• Payment Forms: Fiat deposit/withdrawal interfaces

API Documentation

Bridge Endpoints

POST /api/bridge/swap
{
  sourceChain: "ethereum" | "stellar",
  targetChain: "ethereum" | "stellar",
  amount: string,
  senderAddress: string
}

Rate Endpoints

GET /api/rates/exchange-rate?fromCurrency=NGN&toCurrency=USDC

Payment Endpoints

POST /api/payments/deposit
{
  method: "bank" | "card" | "mobile" | "ussd",
  amount: string,
  currency: string
}

POST /api/payments/withdraw
{
  method: "bank" | "mobile" | "pickup",
  amount: string,
  details: string
}

Security

• Row-level security (RLS) enabled for all database tables
• Secure wallet connection handling
• Real-time transaction monitoring
• Rate limiting on API endpoints
• Input validation and sanitization

Testing

# Run all tests
npm test

# Run specific test suite
npm test ethereum
npm test stellar
npm test rates

Contributing

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request

License

MIT License - see LICENSE for details