Loans

Self-repaying loans using yield-bearing collateral

Loans

Self-repaying loans that use yield from collateral to automatically pay down debt over time.

How It Works

Deposit yield-bearing tokens (e.g., staked ETH, yield vaults)
Borrow synthetic assets up to 50% of collateral value
Yield accrues and automatically pays down your debt
Withdraw when debt is paid or redeem synthetics 1:1

Key Concepts

Collateralization

Minimum 200% collateralization (50% LTV)
Positions cannot be liquidated by price movements - only by debt ceiling

Synthetic Assets

luxUSD: Synthetic dollar, backed by yield-bearing stablecoins
luxETH: Synthetic ETH, backed by yield-bearing ETH

Functions

deposit

function deposit(
    address yieldToken,
    uint256 amount,
    address recipient
) external returns (uint256 shares)

Deposit yield-bearing tokens as collateral.

mint

function mint(
    uint256 amount,
    address recipient
) external

Borrow synthetic tokens against your collateral.

burn

function burn(
    uint256 amount,
    address recipient
) external returns (uint256)

Repay debt by burning synthetic tokens.

withdraw

function withdraw(
    address yieldToken,
    uint256 shares,
    address recipient
) external returns (uint256)

Withdraw collateral.

liquidate

function liquidate(
    address owner,
    uint256 shares,
    uint256 minimumAmountOut
) external returns (uint256)

Liquidate underwater positions (when debt exceeds collateral value).

Usage Example

import "@luxfi/standard/src/Loans.sol";

// Deposit yield-bearing USDC
IERC20(yieldUSDC).approve(address(loans), amount);
loans.deposit(yieldUSDC, amount, msg.sender);

// Mint luxUSD (up to 50% of collateral value)
uint256 maxMint = loans.getMintLimit(msg.sender);
loans.mint(maxMint / 2, msg.sender);

// Check position
(int256 debt, address[] memory tokens) = loans.accounts(msg.sender);

// Debt auto-repays from yield over time
// Eventually withdraw collateral when debt is 0
loans.withdraw(yieldUSDC, shares, msg.sender);

Account Structure

struct Account {
    int256 debt;                                    // Positive = debt, negative = credit
    mapping(address => uint256) balances;           // Share balances per yield token
    mapping(address => uint256) lastAccruedWeights; // Last accrued weights
    Sets.AddressSet depositedTokens;                // Deposited yield tokens
}

Constants

Name	Value	Description
`BPS`	10000	Basis points divisor
`FIXED_POINT_SCALAR`	1e18	Fixed point precision
`minimumCollateralization`	2e18	200% (2x collateral required)

Events

event Deposit(address indexed sender, address indexed yieldToken, uint256 amount, address recipient);
event Withdraw(address indexed sender, address indexed yieldToken, uint256 shares, address recipient);
event Mint(address indexed sender, uint256 amount, address recipient);
event Burn(address indexed sender, uint256 amount, address recipient);
event Liquidate(address indexed sender, address indexed owner, uint256 shares);

Loans

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