PingPay

PingPay is an AI-powered money app on Arbitrum that turns conversations into transactions.

PingPay turns natural language into on-chain actions. PAY people instantly, SWEEP idle stables into yield, and INVEST into Bitcoin or Stocks — all from chat. Our first product, "PAY," allows anyone to send USDC to any type of identifier, like WhatsApp, Email ID or a Telegram handle. The receiver does not need PingPay or a crypto wallet.

🔗 Links

• Working UI: https://pingpay-gz36.vercel.app/
• Subscribe to the @pingpay_bot bot on Telegram to test the feature

🚀 Features

• Chat Command Interface: Type natural commands like send 20 usdc to @alice
• One-Click Claims: Recipients get a Telegram message with a claim link
• No Wallet Required: Recipients can claim without having a crypto wallet
• Real-time Status: Track transactions with ✅ (confirmed) and ✅✅ (claimed) indicators
• Mobile-First Design: iOS-optimized PWA-ready interface

🏗️ Architecture

PingPay/
├── backend/          # Node.js/Express API server
│   ├── src/
│   │   ├── index.js          # Express app entry
│   │   ├── database.js       # SQLite database
│   │   ├── services/
│   │   │   ├── blockchain.js # Ethers.js USDC transfers
│   │   │   └── telegram.js   # Telegram bot notifications
│   │   └── routes/
│   │       ├── transfers.js  # Send/parse commands
│   │       ├── wallets.js    # Wallet management
│   │       └── claims.js     # Claim verification
│   └── data/                 # SQLite database file
│
└── frontend/         # React + Vite + TailwindCSS
    ├── src/
    │   ├── pages/
    │   │   ├── HomePage.jsx    # Main chat interface
    │   │   ├── ClaimPage.jsx   # Recipient claim flow
    │   │   └── HistoryPage.jsx # Transaction history
    │   ├── components/
    │   │   ├── ConfirmModal.jsx
    │   │   └── AddFundsModal.jsx
    │   └── context/
    │       └── WalletContext.jsx
    └── public/

📦 Tech Stack

Backend:

• Node.js + Express
• SQLite (simple file-based DB)
• Ethers.js v6 (blockchain interactions)
• node-telegram-bot-api

Frontend:

• React 18
• Vite
• TailwindCSS
• React Router
• Lucide Icons

Blockchain:

• Arbitrum Sepolia (testnet)
• USDC ERC-20 transfers

🛠️ Setup

Prerequisites

• Node.js 18+
• npm or yarn
• Telegram Bot Token (from @BotFather)
• Arbitrum Sepolia wallet with ETH for gas

Backend Setup

cd backend

# Install dependencies
npm install

# Configure environment
cp .env.example .env
# Edit .env with your values:
# - TELEGRAM_BOT_TOKEN
# - DEMO_WALLET_PRIVATE_KEY

# Create data directory
mkdir -p data

# Start server
npm run dev

Frontend Setup

cd frontend

# Install dependencies
npm install

# Start dev server
npm run dev

The app will be available at http://localhost:5173

🔑 Environment Variables

Backend (.env)

PORT=3001
TELEGRAM_BOT_TOKEN=your_telegram_bot_token
RPC_URL=https://sepolia-rollup.arbitrum.io/rpc
USDC_CONTRACT_ADDRESS=0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d
CHAIN_ID=421614
DEMO_WALLET_PRIVATE_KEY=your_private_key
FRONTEND_URL=http://localhost:5173

📱 User Flows

Flow A: Send USDC

1. Open PingPay web app
2. Type: send 20 usdc to @alice
3. Review confirmation modal → Confirm & Send
4. Transaction broadcasts → shows ✅ when confirmed
5. Recipient gets Telegram notification with claim link

Flow B: Claim USDC

1. Recipient receives Telegram message with link
2. Opens claim page → sees "You received 20 USDC"
3. Enters Telegram handle → clicks Claim
4. Sees balance + options (Send, Withdraw, Earn)
5. Sender's UI updates to ✅✅

🧪 Testing

Get Testnet USDC

1. Visit Circle Faucet
2. Select Arbitrum Sepolia
3. Enter your wallet address
4. Receive testnet USDC

Get Testnet ETH (for gas)

1. Visit Arbitrum Sepolia Faucet
2. Enter your wallet address

📊 API Endpoints

Transfers

• POST /api/transfers/parse - Parse send command
• POST /api/transfers/estimate - Get gas estimate
• POST /api/transfers/send - Execute transfer
• GET /api/transfers/:id - Get transfer details
• GET /api/transfers/history/:address - Get transfer history

Wallets

• GET /api/wallets/demo - Get demo wallet info
• GET /api/wallets/balance/:address - Get balances
• GET /api/wallets/handle/:handle - Get wallet by Telegram handle
• POST /api/wallets/create - Create wallet for handle

Claims

• GET /api/claims/:token - Get claim info
• POST /api/claims/:token/verify - Verify and claim

🎯 Demo Mode

The app runs in demo mode with a prefunded wallet. For production:

• Implement proper wallet authentication
• Add recovery mechanisms for recipient wallets
• Integrate proper Telegram chat ID storage
• Add rate limiting and security measures

📄 License

MIT