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Vault Contract

The Vault contract implements ERC4626 tokenized vault functionality for earning yield generated by borrower’s interest. Contract implementation

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ERC4626 Standard Functions

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deposit

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

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mint

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

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withdraw

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

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redeem

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)

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View Functions

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totalAssets

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.

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convertToShares

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

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convertToAssets

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

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maxDeposit

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)

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maxMint

function maxMint(address) public view override returns (uint256)
Returns the maximum amount of shares that can be minted. Returns:
  • uint256: Maximum mint amount

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maxWithdraw

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

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maxRedeem

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

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previewDeposit

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

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previewMint

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

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previewWithdraw

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

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previewRedeem

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

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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

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Yield and Staking Features

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accrueInterest

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

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Security Considerations

  • All state-changing functions accrue interest first
  • Share calculations use current total assets
  • First depositor loses 0.1 Coin of their deposit