Vault

The Vault is an ERC4626-compliant vault where lenders deposit the borrowed token (e.g., USDC, WETH) to earn yield from borrower interest. Each lending market has its own isolated vault instance deployed by the LendFactory.

The vault's pricePerShare increases over time as borrowers pay interest. It implements the full ERC20 and ERC4626 interfaces, with additional Curve-specific methods for APR reporting and supply limits.

The vault uses a dead shares mechanism (minting 1000 shares to the zero address on initialization) to protect against ERC4626 inflation attacks.

Vault.vy

The source code for the Vault.vy contract can be found on GitHub. The contract is written in Vyper version 0.4.3.

Deployment addresses will be added once contracts are finalized.

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ERC4626 — Deposits and Withdrawals

deposit

Vault.deposit(_assets: uint256, _receiver: address) -> uint256

Deposits the specified amount of borrowed tokens into the vault and mints shares to the receiver.

Input	Type	Description
_assets	uint256	Amount of borrowed tokens to deposit
_receiver	address	Address to receive the minted vault shares

Returns: number of shares minted (uint256).

Emits: Deposit event.

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mint

Vault.mint(_shares: uint256, _receiver: address) -> uint256

Mints an exact number of vault shares by depositing the required amount of borrowed tokens.

Input	Type	Description
_shares	uint256	Exact number of shares to mint
_receiver	address	Address to receive the minted shares

Returns: amount of assets deposited (uint256).

Emits: Deposit event.

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withdraw

Vault.withdraw(_assets: uint256, _receiver: address, _owner: address) -> uint256

Withdraws an exact amount of borrowed tokens by burning the required vault shares.

Input	Type	Description
_assets	uint256	Exact amount of borrowed tokens to withdraw
_receiver	address	Address to receive the withdrawn tokens
_owner	address	Address whose shares are burned

Returns: number of shares burned (uint256).

Emits: Withdraw event.

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redeem

Vault.redeem(_shares: uint256, _receiver: address, _owner: address) -> uint256

Burns an exact number of vault shares and returns the corresponding borrowed tokens.

Input	Type	Description
_shares	uint256	Exact number of shares to burn
_receiver	address	Address to receive the withdrawn tokens
_owner	address	Address whose shares are burned

Returns: amount of assets withdrawn (uint256).

Emits: Withdraw event.

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ERC4626 — Preview and Limits

totalAssets

Vault.totalAssets() -> uint256: view

Returns the total amount of borrowed tokens managed by the vault, including tokens lent out to borrowers (tracked by the controller's debt accounting).

Returns: total assets (uint256).

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convertToShares

Vault.convertToShares(_assets: uint256) -> uint256: view

Returns the number of vault shares that would be minted for a given amount of assets.

Input	Type	Description
_assets	uint256	Amount of assets

Returns: equivalent shares (uint256).

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convertToAssets

Vault.convertToAssets(_shares: uint256) -> uint256: view

Returns the amount of assets that a given number of shares is worth.

Input	Type	Description
_shares	uint256	Amount of shares

Returns: equivalent assets (uint256).

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previewDeposit

Vault.previewDeposit(_assets: uint256) -> uint256: view

Simulates a deposit and returns the number of shares that would be minted. Rounds down.

Input	Type	Description
_assets	uint256	Amount of assets to deposit

Returns: shares that would be minted (uint256).

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previewMint

Vault.previewMint(_shares: uint256) -> uint256: view

Simulates a mint and returns the amount of assets required. Rounds up.

Input	Type	Description
_shares	uint256	Number of shares to mint

Returns: assets required (uint256).

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previewWithdraw

Vault.previewWithdraw(_assets: uint256) -> uint256: view

Simulates a withdrawal and returns the number of shares that would be burned. Rounds up.

Input	Type	Description
_assets	uint256	Amount of assets to withdraw

Returns: shares that would be burned (uint256).

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previewRedeem

Vault.previewRedeem(_shares: uint256) -> uint256: view

Simulates a redemption and returns the amount of assets that would be returned. Rounds down.

Input	Type	Description
_shares	uint256	Number of shares to redeem

Returns: assets that would be returned (uint256).

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maxDeposit

Vault.maxDeposit(_receiver: address) -> uint256: view

Returns the maximum amount of assets that can be deposited for a given receiver, considering the supply limit.

Input	Type	Description
_receiver	address	Receiver address

Returns: max depositable assets (uint256).

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maxMint

Vault.maxMint(_receiver: address) -> uint256: view

Returns the maximum number of shares that can be minted for a given receiver.

Input	Type	Description
_receiver	address	Receiver address

Returns: max mintable shares (uint256).

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maxWithdraw

Vault.maxWithdraw(_owner: address) -> uint256: view

Returns the maximum amount of assets that can be withdrawn by a given owner, limited by available liquidity.

Input	Type	Description
_owner	address	Owner of the shares

Returns: max withdrawable assets (uint256).

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maxRedeem

Vault.maxRedeem(_owner: address) -> uint256: view

Returns the maximum number of shares that can be redeemed by a given owner.

Input	Type	Description
_owner	address	Owner of the shares

Returns: max redeemable shares (uint256).

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pricePerShare

Vault.pricePerShare() -> uint256: view

Returns the current price per share, scaled to 1e18. Increases over time as interest accrues.

Returns: price per share (uint256).

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APR

borrow_apr

Vault.borrow_apr() -> uint256: view

Returns the current annualized borrow rate as reported by the monetary policy, scaled to 1e18.

Returns: borrow APR (uint256).

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lend_apr

Vault.lend_apr() -> uint256: view

Returns the current annualized lending rate — the effective yield lenders earn after accounting for utilization and admin fees, scaled to 1e18.

Returns: lend APR (uint256).

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Vault Info

asset

Vault.asset() -> address: view

Returns the address of the underlying borrowed token (the ERC4626 asset).

Returns: asset address (address).

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borrowed_token

Vault.borrowed_token() -> address: view

Returns the borrowed token address.

Returns: token address (address).

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collateral_token

Vault.collateral_token() -> address: view

Returns the collateral token address for this market.

Returns: token address (address).

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controller

Vault.controller() -> address: view

Returns the LendController address associated with this vault.

Returns: controller address (address).

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amm

Vault.amm() -> address: view

Returns the AMM (LLAMMA) address associated with this vault.

Returns: AMM address (address).

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factory

Vault.factory() -> address: view

Returns the factory that deployed this vault.

Returns: factory address (address).

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Admin

set_max_supply

Vault.set_max_supply(_max_supply: uint256)

Guarded Method

This function is only callable by the admin, which is the factory owner.

Sets the maximum supply cap for the vault. When set, deposits that would push totalSupply above this limit are rejected.

Input	Type	Description
_max_supply	uint256	New maximum supply cap (0 = unlimited)

Emits: SetMaxSupply event.

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admin

Vault.admin() -> address: view

Returns the admin of the vault, which is the owner of the factory contract.

Returns: admin address (address).

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ERC20

The vault implements the full ERC20 interface for vault share tokens.

transfer

Vault.transfer(_to: address, _value: uint256) -> bool

Transfers vault shares to another address.

Input	Type	Description
_to	address	Recipient address
_value	uint256	Amount of shares to transfer

Returns: success (bool).

Emits: Transfer event.

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transferFrom

Vault.transferFrom(_from: address, _to: address, _value: uint256) -> bool

Transfers vault shares from one address to another, using the caller's allowance.

Input	Type	Description
_from	address	Sender address
_to	address	Recipient address
_value	uint256	Amount of shares to transfer

Returns: success (bool).

Emits: Transfer event.

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approve

Vault.approve(_spender: address, _value: uint256) -> bool

Approves an address to spend vault shares on behalf of the caller.

Input	Type	Description
_spender	address	Address to approve
_value	uint256	Allowance amount

Returns: success (bool).

Emits: Approval event.

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increaseAllowance

Vault.increaseAllowance(_spender: address, _add_value: uint256) -> bool

Increases the allowance for a spender by a given amount.

Input	Type	Description
_spender	address	Address whose allowance to increase
_add_value	uint256	Amount to add to the current allowance

Returns: success (bool).

Emits: Approval event.

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decreaseAllowance

Vault.decreaseAllowance(_spender: address, _sub_value: uint256) -> bool

Decreases the allowance for a spender by a given amount.

Input	Type	Description
_spender	address	Address whose allowance to decrease
_sub_value	uint256	Amount to subtract from the current allowance

Returns: success (bool).

Emits: Approval event.

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