ChainMoney

A peer-to-peer payment application built with Next.js, Alchemy Account Kit, and AAVE Protocol. Send USDC payments to other users while optionally earning yield on your balance.

Features

• Smart Account Wallet: Powered by Alchemy Account Kit with email-based authentication
• Instant P2P Payments: Send USDC to other users on the platform
• Yield Earning: Automatically earn interest on your balance through AAVE Protocol
• Intelligent Token Conversion: Automatically converts between USDC and aUSDC based on recipient preferences
• Gas Sponsorship: All transactions are gasless thanks to Alchemy's gas sponsorship
• Activity Feed: View all platform transactions in real-time
• Transaction History: Track all your sent and received payments

Tech Stack

• Framework: Next.js 15 with App Router
• Styling: Tailwind CSS
• UI Components: shadcn/ui
• Database: PostgreSQL with Drizzle ORM
• Smart Accounts: Alchemy Account Kit
• DeFi Protocol: AAVE V3
• Network: Base Sepolia (testnet)

Prerequisites

• Node.js 18+
• PostgreSQL database (local or hosted)
• Alchemy account with API key and Gas Policy ID
• Git

Getting Started

1. Clone the repository

git clone https://github.com/alchemyplatform/chain-money-account-kit.git
cd chain-money-account-kit

2. Install dependencies

npm install

3. Set up environment variables

Copy .env.example to .env.local:

cp .env.example .env.local

Then update the values:

# Database Configuration
DATABASE_URL=postgresql://user:password@host:port/database

# Alchemy Configuration
ALCHEMY_API_KEY=your-alchemy-api-key
ALCHEMY_POLICY_ID=your-alchemy-gas-policy-id

Getting Alchemy Credentials

1. Sign up at Alchemy Dashboard
2. Create a new app on Base Sepolia network
3. Get your API key from the app dashboard
4. Create a Gas Policy:
   • Navigate to Account Kit → Gas Manager
   • Create a new policy for Base Sepolia
   • Copy the Policy ID

4. Set up the database

Run the database migrations:

npm run db:push

5. Run the development server

npm run dev

Open http://localhost:3000 to see the app.

How It Works

Smart Account Authentication

Users authenticate via email using Alchemy Account Kit, which creates a smart contract wallet for each user. No seed phrases or private keys needed!

Payment Flow with Yield Conversion

The app intelligently handles different token preferences:

1. Check balances: Sender's USDC and aUSDC balances are checked
2. Determine token: Based on recipient's yield preference (earning or not)
3. Convert if needed:
   • If recipient wants yield but sender has USDC → Convert to aUSDC via AAVE
   • If recipient doesn't want yield but sender has aUSDC → Withdraw from AAVE to USDC
4. Send payment: Transfer the correct token in a single atomic transaction

All operations (approve, supply/withdraw, transfer) are batched together for efficiency.

Yield Earning

When yield earning is enabled on the /wallet page:

• USDC is deposited into AAVE Protocol
• User receives aUSDC (interest-bearing tokens)
• Balance automatically grows over time
• Can be withdrawn at any time

Project Structure

├── app/                    # Next.js app router pages
│   ├── api/               # API routes
│   │   ├── profile/       # User profile management
│   │   ├── rpc/           # Alchemy RPC proxy
│   │   ├── transactions/  # Transaction recording
│   │   └── users/         # User listing
│   ├── send-payment/      # Payment sending page
│   ├── wallet/            # Wallet management page
│   └── page.tsx           # Home page
├── components/            # React components
│   ├── ui/               # shadcn/ui components
│   └── ...               # Custom components
├── contexts/              # React contexts
│   ├── smart-account-context.tsx  # Account Kit integration
│   └── user-context.tsx   # User profile state
├── hooks/                 # Custom React hooks
├── lib/                   # Utilities and configurations
│   ├── aave-abis.ts      # AAVE contract ABIs
│   ├── account-kit-config.ts  # Account Kit setup
│   └── constants.ts       # Contract addresses
└── src/
    └── db/               # Database configuration
        └── schema.ts     # Drizzle schema

Key Smart Contracts (Base Sepolia)

• USDC: 0x036CbD53842c5426634e7929541eC2318f3dCF7e
• aUSDC: 0xf53B60F4006cab2b3C4688ce41fD5362427A2A66
• AAVE V3 Pool: 0x07eA79F68B2B3df564D0A34F8e19D9B1e339814b

Development

Database Changes

After modifying src/db/schema.ts, push changes to the database:

npm run db:push

Type Checking

npx tsc --noEmit

Linting

npm run lint

Testing with Testnet Funds

1. Navigate to the Wallet page
2. Copy your smart account address
3. Get test USDC from Circle Faucet
   • Select Base Sepolia network
   • Paste your address
   • Request 10 USDC

Deployment

This app can be deployed to Vercel:

Make sure to add all environment variables from .env.example to your Vercel project settings.

Learn More

• Alchemy Account Kit Documentation
• AAVE V3 Documentation
• Next.js Documentation
• Drizzle ORM Documentation

License

MIT