Vault Contract

ERC4626-compliant vault contract for managing user deposits and yield strategies

Overview

The Vault contract is the core entry point for users to deposit assets and receive yield. It implements an ERC4626-like vault with share-based accounting, performance fees, and integration with multiple yield strategies through the StrategyRouter.

Contract Address: Deployed per-asset basis

Inherits: ERC20, Ownable

State Variables

asset · IERC20 · required

Immutable. The underlying asset token (e.g., USDC, LINK) that users deposit.

performanceFeeBps · uint256 · required

Performance fee in basis points (10000 = 100%). Applied to harvested profits.

feeRecipient · address · required

Address that receives performance and withdrawal fees.

withdrawFeeBps · uint256 · required

Withdrawal fee in basis points (10000 = 100%). Applied when users withdraw.

router · address · required

Address of the StrategyRouter contract that manages yield strategies.

netDeposited · mapping(address => uint256) · required

Tracks total deposits per user for growth calculation.

totalWithdrawn · mapping(address => uint256) · required

Tracks total withdrawals per user for growth calculation.

Events

Deposit

event Deposit(address indexed user, uint256 amount, uint256 shares)

Emitted when a user deposits assets.

user · address

Address of the depositor

amount · uint256

Amount of assets deposited

shares · uint256

Amount of vault shares minted

Withdraw

event Withdraw(address indexed user, uint256 amount, uint256 shares)

Emitted when a user withdraws assets.

user · address

Address of the withdrawer

amount · uint256

Amount of assets withdrawn (after fees)

shares · uint256

Amount of vault shares burned

Constructor

constructor(
    address _asset,
    address _feeRecipient,
    uint256 _performanceBps,
    uint256 _withdrawFeeBps
) ERC20("Vault Share Token", "VST") Ownable(msg.sender)

_asset · address · required

Address of the underlying asset token

_feeRecipient · address · required

Address to receive fees

_performanceBps · uint256 · required

Performance fee in basis points (e.g., 1000 = 10%)

_withdrawFeeBps · uint256 · required

Withdrawal fee in basis points (e.g., 50 = 0.5%)

Public Functions

deposit

function deposit(uint256 amount) external returns (uint256)

Deposit assets into the vault and receive shares.

amount · uint256 · required

Amount of assets to deposit

shares · uint256

Amount of vault shares minted to the depositor

Requirements:

• Caller must have approved the vault to transfer amount of asset tokens
• amount must be greater than 0

Example:

// Approve vault to spend USDC
usdc.approve(address(vault), 1000e6);

// Deposit 1000 USDC
uint256 shares = vault.deposit(1000e6);

withdraw

function withdraw(uint256 shares) external returns (uint256 assetsOut)

Burn shares and withdraw underlying assets. If vault doesn’t have enough liquidity, pulls from strategies.

shares · uint256 · required

Amount of shares to burn

assetsOut · uint256

Amount of assets transferred to user (after withdrawal fee)

Requirements:

• shares must be greater than 0
• Caller must have sufficient shares
• Router must be set if strategies need to be tapped

Example:

// Withdraw all shares
uint256 shares = vault.balanceOf(msg.sender);
uint256 assetsReceived = vault.withdraw(shares);

convertToShares

function convertToShares(uint256 assets) public view returns (uint256)

Convert an asset amount to shares based on current vault state.

assets · uint256 · required

Amount of assets

shares · uint256

Equivalent shares amount

convertToAssets

function convertToAssets(uint256 shares) public view returns (uint256)

Convert shares to asset amount based on current vault state.

shares · uint256 · required

Amount of shares

assets · uint256

Equivalent assets amount

totalAssets

function totalAssets() public view returns (uint256)

Returns the amount of assets held directly in the vault (not in strategies).

assets · uint256

Amount of assets in vault

totalManagedAssets

function totalManagedAssets() public view returns (uint256)

Returns total assets under management (vault + all strategies).

total · uint256

Total assets in vault and all strategies

getNAV

function getNAV() external view returns (uint256)

Get Net Asset Value - same as totalManagedAssets().

nav · uint256

Total net asset value

availableLiquidity

function availableLiquidity() external view returns (uint256)

Get immediately available liquidity (vault balance only, excluding strategies).

liquidity · uint256

Available liquidity for instant withdrawals

userGrowth

function userGrowth(address user) public view returns (int256)

Calculate absolute profit/loss for a user.

user · address · required

User address to check

pnl · int256

Profit (positive) or loss (negative) in asset units

Formula: (currentValue + totalWithdrawn) - netDeposited

userGrowthPercent

function userGrowthPercent(address user) external view returns (int256)

Calculate percentage growth for a user.

user · address · required

User address to check

growthPercent · int256

Growth percentage scaled by 1e18 (1e18 = 100%)

Example:

int256 growth = vault.userGrowthPercent(msg.sender);
if (growth > 0) {
    // User has profit: growth / 1e18 * 100 = percentage
    // Example: 5e17 = 50% gain
}

Owner Functions

setRouter

function setRouter(address _router) external onlyOwner

Set the StrategyRouter contract address.

_router · address · required

Address of the StrategyRouter contract

Router-Only Functions

moveToStrategy

function moveToStrategy(address strategy, uint256 amount) external onlyRouter

Move funds from vault to a strategy. Called by StrategyRouter during rebalancing.

strategy · address · required

Strategy contract address

amount · uint256 · required

Amount of assets to move

receiveFromStrategy

function receiveFromStrategy(uint256 amount) external onlyRouter

Accounting function called when router pulls funds from strategy back to vault.

amount · uint256 · required

Amount received from strategy

handleHarvestProfit

function handleHarvestProfit(uint256 profit) external onlyRouter

Process harvested profits and apply performance fee.

profit · uint256 · required

Amount of profit harvested

Behavior:

• Calculates fee: fee = profit * performanceFeeBps / 10000
• Transfers fee to feeRecipient
• Remaining profit stays in vault to increase share value

Integration Example

// Deploy vault for USDC
Vault vault = new Vault(
    address(usdc),           // asset
    feeRecipient,            // fee recipient
    1000,                    // 10% performance fee
    50                       // 0.5% withdrawal fee
);

// Set router
vault.setRouter(address(strategyRouter));

// User deposits
usdc.approve(address(vault), 10000e6);
uint256 shares = vault.deposit(10000e6);

// Check user's position value
uint256 value = vault.convertToAssets(vault.balanceOf(msg.sender));

// Check user's profit
int256 profit = vault.userGrowth(msg.sender);
int256 profitPct = vault.userGrowthPercent(msg.sender);

// Withdraw
vault.withdraw(shares);

Security Considerations

1. Router Trust: The router has privileged access to move funds. Ensure router contract is audited.
2. Fee Limits: Consider implementing maximum fee caps (e.g., performanceFeeBps 2000 for 20% max).
3. Reentrancy: Uses SafeERC20 which provides reentrancy protection.
4. Share Inflation: First depositor should deposit significant amount to prevent share manipulation attacks.

See Also

• StrategyRouter - Manages strategy allocations
• StrategyAave - Aave lending strategy
• StrategyAaveLeverage - Leveraged Aave strategy