CollateralX

A lending protocol that allows users to deposit ETH as collateral and borrow stablecoins against it.

Key Features

• Deposit ETH as collateral
• Borrow stablecoins (150% collateral ratio)
• Multiple loans per collateral
• Flexible loan repayment
• Liquidation (120% threshold)
• 10% annual interest rate
• Real-time ETH/USD price feeds via Chainlink

Contracts

CollateralX.sol

// Main functions
depositCollateral() external payable
borrowStableCoin(uint256 amount) external
repayStableCoin(uint256 amount, uint256[] calldata indexes) external
withdrawCollateral(uint256 amount) external
getLoanStatus(address user) external view
liquidate(address user) external

TestCoin.sol

• ERC20 stablecoin for testing
• Includes faucet function

TestPriceFeed.sol

• Implements AggregatorV3Interface for ETH/USD price feed
• Allows price updates for testing scenarios

Contract Interactions

// 1. Deploy contracts
const stableCoin = await TestCoin.deploy()
const testPriceFeed = await TestPriceFeed.deploy(ethers.parseUnits("1000", 8)) // $1000/ETH
const collateralX = await CollateralX.deploy(stableCoin.address, testPriceFeed.address)

// 2. Deposit ETH (1 ETH)
await collateralX.depositCollateral({ 
    value: parseEther("1.0") 
})

// 3. Borrow (1000 stablecoins)
const borrowAmount = parseUnits("1000", 18)
await collateralX.borrowStableCoin(borrowAmount)

// 4. Repay (requires approval first)
const repayAmount = parseUnits("1000", 18)
await stableCoin.approve(collateralX.address, repayAmount)
await collateralX.repayStableCoin(repayAmount, [0])  // repay first loan

// 5. Liquidate undercollateralized position (requires approval)
const userToLiquidate = "0x..."
const loanStatus = await collateralX.getLoanStatus(userToLiquidate)
const totalDebt = loanStatus.reduce((acc, loan) => acc + loan.principal + loan.interest, 0)
await stableCoin.approve(collateralX.address, totalDebt)
await collateralX.liquidate(userToLiquidate)

Setup

npm install          # Install dependencies
npm test             # Run tests

Deployment

Environment Setup

Create a .env file in the root directory:

PRIVATE_KEY=your_deployer_account_private_key
SEPOLIA_RPC_URL=your_sepolia_rpc_url
ETHERSCAN_API_KEY=your_etherscan_api_key
CHAINLINK_ETH_USD_FEED=0x694AA1769357215DE4FAC081bf1f309aDC325306

Local Deployment

# Terminal 1
npm run compile
npm run node

# Terminal 2
npm run deploy:localhost

The local network:

• RPC URL: http://127.0.0.1:8545
• Chain ID: 31337
• Pre-funded accounts with 10,000 ETH each

The deployment script will:

• Deploy TestCoin contract
• Deploy TestPriceFeed contract
• Deploy CollateralX contract
• Fund CollateralX with 1,000,000 TestCoins for lending
• Display contract addresses

Sepolia Deployment

npm run compile
npm run deploy:sepolia

Security Notes

• Maintain >150% collateral ratio
• Positions below 120% can be liquidated
• Interest accumulates over time
• Uses Chainlink's trusted price feeds for accurate ETH valuation

License

MIT