> ## Documentation Index > Fetch the complete documentation index at: https://docs.monolith.market/llms.txt > Use this file to discover all available pages before exploring further. # Vault > ERC4626 vault implementation for yield farming # Vault Contract The Vault contract implements ERC4626 tokenized vault functionality for earning yield generated by borrower's interest. [Contract implementation](https://github.com/MonolithMarket/Monolith/blob/main/src/Vault.sol) ## ERC4626 Standard Functions ### deposit ```solidity theme={null} function deposit(uint256 assets, address receiver) public accrueInterest override returns (uint256 shares) ``` Deposits assets into the vault and mints corresponding vault shares to receiver. **Parameters:** * `assets`: Amount of underlying assets to deposit (in wei) * `receiver`: Address to receive the vault shares **Returns:** * `shares`: Amount of vault shares minted **Requirements:** * `assets` must be > 0 * Caller must have approved vault for asset transfer * If this is the first ever deposit into the vault, the minted shares must be at least `MIN_SHARES` (1e16); otherwise the transaction reverts **Effects:** * Transfers assets from caller to vault * Mints shares to receiver * Updates total assets * Accrues interest before deposit * On the first ever deposit, `MIN_SHARES` shares are burned from the receiver and sent to `address(0)` to initialize share pricing; the receiver's net minted shares are reduced by `MIN_SHARES` *** ### mint ```solidity theme={null} function mint(uint256 shares, address receiver) public accrueInterest override returns (uint256 assets) ``` Mints exact amount of vault shares by depositing corresponding assets. **Parameters:** * `shares`: Exact amount of shares to mint * `receiver`: Address to receive the vault shares **Returns:** * `assets`: Amount of assets required for the mint **Requirements:** * `shares` must be > 0 * Caller must have sufficient assets approved * If this is the first ever mint into the vault, the requested `shares` must be at least `MIN_SHARES` (1e16); otherwise the transaction reverts **Effects:** * Calculates required assets based on current share price * Transfers assets from caller to vault * Mints exact shares to receiver * On the first ever mint, `MIN_SHARES` shares are burned from the receiver and sent to `address(0)`; the corresponding `assets` are effectively reserved *** ### withdraw ```solidity theme={null} function withdraw( uint256 assets, address receiver, address owner ) public accrueInterest override returns (uint256 shares) ``` Burns vault shares and returns corresponding assets to receiver. **Parameters:** * `assets`: Amount of assets to withdraw * `receiver`: Address to receive the assets * `owner`: Address that owns the shares (can be different from caller with approval) **Returns:** * `shares`: Amount of shares burned **Requirements:** * `assets` must be ≤ owner's balance * If `owner != msg.sender`, caller must have withdrawal approval * Vault must have sufficient assets **Effects:** * Burns shares from owner * Transfers assets to receiver * Updates total assets *** ### redeem ```solidity theme={null} function redeem( uint256 shares, address receiver, address owner ) public accrueInterest override returns (uint256 assets) ``` Burns exact amount of vault shares and returns corresponding assets. **Parameters:** * `shares`: Amount of shares to redeem * `receiver`: Address to receive the assets * `owner`: Address that owns the shares **Returns:** * `assets`: Amount of assets returned **Requirements:** * `shares` must be ≤ owner's balance * If `owner != msg.sender`, caller must have approval **Effects:** * Burns shares from owner * Transfers assets to receiver * Returns actual assets received (may differ due to rounding) *** ## View Functions ### totalAssets ```solidity theme={null} function totalAssets() public view override returns (uint256) ``` Returns the total amount of underlying assets held by the vault. **Returns:** * `uint256`: Total assets in wei **Note:** Returns the current `asset` token balance held by the vault contract. *** ### convertToShares ```solidity theme={null} function convertToShares(uint256 assets) public view override returns (uint256) ``` Calculates the amount of shares that would be minted for given assets. **Parameters:** * `assets`: Amount of assets to convert **Returns:** * `uint256`: Equivalent shares amount *** ### convertToAssets ```solidity theme={null} function convertToAssets(uint256 shares) public view override returns (uint256) ``` Calculates the amount of assets that would be returned for given shares. **Parameters:** * `shares`: Amount of shares to convert **Returns:** * `uint256`: Equivalent assets amount *** ### maxDeposit ```solidity theme={null} function maxDeposit(address) public view override returns (uint256) ``` Returns the maximum amount of assets that can be deposited. **Returns:** * `uint256`: Maximum deposit amount (type(uint256).max if unlimited) *** ### maxMint ```solidity theme={null} function maxMint(address) public view override returns (uint256) ``` Returns the maximum amount of shares that can be minted. **Returns:** * `uint256`: Maximum mint amount *** ### maxWithdraw ```solidity theme={null} function maxWithdraw(address owner) public view override returns (uint256) ``` Returns the maximum amount of assets that can be withdrawn by owner. **Parameters:** * `owner`: Address to check withdrawal limit for **Returns:** * `uint256`: Maximum withdrawable assets *** ### maxRedeem ```solidity theme={null} function maxRedeem(address owner) public view override returns (uint256) ``` Returns the maximum amount of shares that can be redeemed by owner. **Parameters:** * `owner`: Address to check redemption limit for **Returns:** * `uint256`: Maximum redeemable shares *** ### previewDeposit ```solidity theme={null} function previewDeposit(uint256 assets) public view override returns (uint256) ``` Previews the amount of shares that would be minted for a deposit. **Parameters:** * `assets`: Amount of assets to deposit **Returns:** * `uint256`: Expected shares to receive *** ### previewMint ```solidity theme={null} function previewMint(uint256 shares) public view override returns (uint256) ``` Previews the amount of assets required to mint given shares. **Parameters:** * `shares`: Amount of shares to mint **Returns:** * `uint256`: Required assets amount *** ### previewWithdraw ```solidity theme={null} function previewWithdraw(uint256 assets) public view override returns (uint256) ``` Previews the amount of shares that would be burned for a withdrawal. **Parameters:** * `assets`: Amount of assets to withdraw **Returns:** * `uint256`: Shares to be burned *** ### previewRedeem ```solidity theme={null} function previewRedeem(uint256 shares) public view override returns (uint256) ``` Previews the amount of assets that would be returned for redeeming shares. **Parameters:** * `shares`: Amount of shares to redeem **Returns:** * `uint256`: Assets to be received *** ## ERC20 Functions The vault also implements standard ERC20 functions for shares: * `name()`: Returns vault share token name * `symbol()`: Returns vault share token symbol * `decimals()`: Returns decimals (same as underlying asset) * `totalSupply()`: Returns total vault shares * `balanceOf(address)`: Returns shares balance of address * `transfer(address,uint256)`: Transfers shares * `allowance(address,address)`: Returns transfer allowance * `approve(address,uint256)`: Approves share transfers * `transferFrom(address,address,uint256)`: Transfers shares with approval ## Yield and Staking Features ### accrueInterest ```solidity theme={null} function accrueInterest() external ``` Accrues interest from the underlying lender contract. Must be called before share calculations. **Effects:** * Updates vault's asset balance with accrued interest * Maintains accurate share pricing *** ## Security Considerations * All state-changing functions accrue interest first * Share calculations use current total assets * The first ever depositor forfeits `MIN_SHARES` (1e16 = 0.01 share units) which are burned to `address(0)` to prevent the ERC‑4626 inflation attack