LendPool

lendpool.sol

The LendPool contract is the main contract of the protocol. It exposes all the user-oriented actions that can be invoked using either Solidity or web3 libraries.

The source code can be found on GitHub here**.**

LendPool methods deposit, withdraw, triggerUserCollateral, borrow, repay, auction, redeem, liquidate, and liquidateNFTX are only for ERC20 and ERC721. If you want to deposit, withdraw, triggerUserCollateral, borrow, repay, auction, or redeem using native ETH, use WETHGateway instead. If you want to borrow or repay using CryptoPunks as collateral, use PunkGateway.

View Methods

getReserveConfiguration

function getReserveConfiguration(address asset) external view override returns (DataTypes.ReserveConfigurationMap memory)

Returns the configuration of the reserve.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC20)

Return Values

Type	Description
DataTypes.ReserveConfigurationMap	The reserve configuration values are stored on-chain: LTV, Liq. threshold, Liq. bonus, Decimals, Reserve is active, Reserve is frozen, Borrowing is enabled, Stable rate borrowing enabled, Reserved, Reserve factor uint256 data;

getNftConfigByTokenId

function getNftConfigByTokenId(address asset, uint256 nftTokenId) external view override returns (DataTypes.NftConfigurationMap memory)

Returns the configuration of the NFT collection as a default config.

Each NFT has its own configuration bytokenId, not by collection.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC721)
nftTokenId	uint256	the tokenId of the underlying asset (ERC721)

Return Values

Type	Description
DataTypes.NftConfigurationMap	The reserve configuration values are stored on-chain: LTV, Liq. threshold, Liq. bonus, NFT is active, NFT is frozen, Redeem duration, Auction duration, Redeem fine, Redeem threshold Min bid fine, timestamp config;

getReserveNormalizedIncome

function getReserveNormalizedIncome(address asset) external view override returns (uint256)

Returns the normalized income of the reserve.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC20)

Return Values

Type	Description
uint256	normalized income amount.

getReserveNormalizedVariableDebt

function getReserveNormalizedVariableDebt(address asset) external view override returns (uint256)

Returns the normalized variable debt per unit of asset.

Call Params

asset

address

the address of the underlying asset (ERC20)

Return Params

Type	Description
uint256	normalized variable debt amount

getReserveData

function getReserveData(address asset) external view override returns (DataTypes.ReserveData memory)

Returns the state and configuration of the reserve.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC20)

Return Values

Type	Description
DataTypes.ReserveData	The reserve data struct ReserveConfigurationMap configuration, liquidityIndex, variableBorrowIndex, currentLiquidityRate, currentVariableBorrowRate, lastUpdateTimestamp, uTokenAddress, debtTokenAddress, interestRateAddress, id;

getNftData

function getNftData(address asset) external view override returns (DataTypes.NftData memory)

Returns the state and configuration of the NFT.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC721)

Return Values

Type	Description
DataTypes.NftData	Returns the NFT data Struct: NftConfigurationMap configuration, uNftAddress, id, maxSupply, maxTokenId;

getNftCollateralData

function getNftCollateralData(address nftAsset, uint256 nftTokenId, address reserveAsset) external view override returns (uint256 totalCollateralInETH, uint256 totalCollateralInReserve, uint256 availableBorrowsInETH, uint256 availableBorrowsInReserve, uint256 ltv, uint256 liquidationThreshold, uint256 liquidationBonus)

Returns the loan data of the NFT by TokenId.

Call Params

Name	Type	Description
nftAsset	address	the address of the underlying asset (ERC721)
nftTokenId	uint256	the tokenId of the underlying asset
reserveAsset	address	the address of the underlying reserve asset (ERC20)

Return Values

Name	Type	Description
totalCollateralInETH	uint256	the total collateral in ETH of the NFT
totalCollateralInReserve	uint256	the total collateral in Reserve of the NFT
availableBorrowsInETH	uint256	the borrowing power in ETH of the NFT
availableBorrowsInReserve	uint256	the borrowing power in Reserve of the NFT
ltv	uint256	loan to value for the NFT/User
liquidationThreshold	uint256	the liquidation threshold of the NFT
liquidationBonus	uint256	the liquidation bonus of the NFT

getNftDebtData

function getNftDebtData(address nftAsset, uint256 nftTokenId) external view override returns (uint256 loanId, address reserveAsset, uint256 totalCollateral, uint256 totalDebt, uint256 availableBorrows, uint256 healthFactor)

Returns the debt data of the NFT.

Call Params

Name	Type	Description
nftAsset	address	the address of the underlying asset (ERC721)
nftTokenId	uint256	the tokenId of the underlying asset

Return Values

Name	Type	Description
loanId	uint256	the loan id of the NFT
reserveAsset	address	the address of the Reserve
totalCollateral	uint256	the total power of the NFT
totalDebt	uint256	the total debt of the NFT
availableBorrows	uint256	the borrowing power left of the NFT
healthFactor	uint256	the current health factor of the NFT

getNftAuctionData

function getNftAuctionData(address nftAsset, uint256 nftTokenId) external view override returns (uint256 loanId, address bidderAddress, uint256 bidPrice, uint256 bidBorrowAmount, uint256 bidFine)

Returns the auction data of the NFT.

Call Params

Name	Type	Description
nftAsset	address	the address of the underlying asset (ERC721)
nftTokenId	uint256	the tokenId of the underlying asset

Return Values

Name	Type	Description
loanId	uint256	the loan id of the NFT
bidderAddress	address	the highest bidder address of the loan
bidPrice	uint256	the highest bid price in Reserve of the loan
bidBorrowAmount	uint256	the borrow amount in Reserve of the loan
bidFine	uint256	the penalty fine of the loan paid to the 1st bidder

getReservesList

function getReservesList() external view override returns (address[] memory)

Returns the list of the initialized reserves.

Return Values

Type	Description
array of address (address[])	A list of address, the initialized reserves

getNftsList

function getNftsList() external view override returns (address[] memory)

Returns the list of the initialized NFTs.

Return Values

Type	Description
array of address (address[])	A list of address, the initialized NFT reserves

Write Methods

deposit

function deposit(address asset, uint256 amount, address onBehalfOf, uint16 referralCode) external override nonReentrant whenNotPaused

Deposit the user-chosen amount of a certain asset into the protocol, minting the same amount of corresponding uTokens, and transferring them to the onBehalfOf address.

Example: Bob deposits 100 WETH and will get 100 uWETH in return as proof of the deposited amount.

The referral program is coded but inactive. You can pass a 0 as referralCode.

When depositing, the LendPool contract must haveallowance()to spend funds on behalf ofmsg.sender for at least theamount of the asset being deposited. This can be done via the standard ERC20 approve() method.

Call Params

Name	Type	Description
asset	address	the address of the underlying asset (ERC20)
amount	uint256	the amount to deposit expressed in wei units
onBehalfOf	address	address whom will receive the uTokens. Use msg.sender when the uTokens should be sent to the caller.
referralCode	uint16	the referral program is not working at the moment use 0

withdraw

function withdraw(address asset, uint256 amount, address to) external override nonReentrant whenNotPaused returns (uint256)

Withdraws the amount of the underlying asset based on the amount of uTokens being held and burns the same amount of uTokens.

Example: Bob withdraws 10 ETH. Bob will get 10 ETH and will burn the same amount in uTokens.

When withdrawing to another address, the msg.sendershould hold enough uTokens that the lendPool will burn.

Call Params

Name	Type	Description
asset	address	address of the underlying asset (ERC20)
amount	uint256	the amount to be withdraw expressed in wei units
to	address	the address that will receive the asset.

Return Params

Type	Description
uint256	the amount that was withdrawn

approveValuation

function approveValuation(address nftAsset, uint256 nftTokenId) external payable override onlyHolder(nftAsset, nftTokenId) whenNotPaused

This will ensure that the user holds the nftAsset or the uNFT version of it (ERC721). It will charge a small fee to the user to configure his NFT on the protocol.

This function needs to be done before borrowing. Otherwise, it will revert.

Call Params

Name	Type	Description
nftAsset	address	the adress of the underlying NFT asset used as collateral
nftTokenId	uint256	the TokenId of the underlying NFT asset used as collateral

borrow

function borrow(address asset, uint256 amount, address nftAsset, uint256 nftTokenId, address onBehalfOf, uint16 referralCode) external override nonReentrant whenNotPaused

The user will be able to borrow an amount of asset using his nftAsset as collateral to a wallet onBehalfOf and will also receive the same amount in debt tokens as proof of debt.

Example: Alice borrows 10 ETH using her Lockey NFT with tokenid 1. Alice will lock her NFT and get a uNFT (wrapped version of the collateral), debt tokens representing her debt to the protocol and the 10 ETH.

The referral program is coded but inactive. You can pass a 0 as referralCode.

The borrowing can only be done if your NFT is configured on the protocol.

To do this, the triggerUserCollateral needs to be called first. Also, there's a _timeFrame variable configured that will validate the time between configuring the NFT and the borrow. If the time is exceeded, it will revert.\

The _timeFrame can be checked with getTimeframe()

Call Params

Name	Type	Description
asset	address	The address of the underlying asset to borrow
amount	uint256	the amount to be borrowed expressed in wei units
nftAsset	address	the address of the underlying NFT used as collateral
nftTokenId	uint256	the tokenId of the underlying NFT used as collateral
onBehalfOf	address	address whom will receive the borrowed amount. Use msg.sender when the debt tokens and borrowed amount should be sent to the caller.
referralCode	uint16	the referral program is not working at the moment use 0

repay

function repay(address nftAsset, uint256 nftTokenId, uint256 amount) external override nonReentrant whenNotPaused returns (uint256, bool)

Repays a borrowed amount equal to or less than the amount owed from the specified collateral, nftAsset. It will burn the same amount of debt tokens.

Example: Alice decides to pay 2 ETH from the borrowed amount. Alice will use her uNFT to identify the loan, will give 2 ETH and will burn the same amount in debt tokens.

Call Params

Name	Type	Description
nftAsset	address	the underlying NFT address used as collateral
nftTokenId	uint256	the underlying NFT token Id used as collateral
amount	uint256	the amount that the user wants to repay

Return Values

Type	Description
uint256	the repayed amount
bool	will return true if the total amount is repaid or false if partially paid.

auction

function auction(address nftAsset, uint256 nftTokenId, uint256 bidPrice, address onBehalfOf) external override nonReentrant whenNotPaused

When the health factor is below one, the users can trigger an auction if they want to buy the collateral asset, the NFT used in the loan. The bidPrice needs to be higher than

When a user bids, the money gets locked on the contract till someone outbids or the liquidation happens.

Example: Alice's NFT price went down, and the health factor (HF) went below 1. Bob, that loves the Lockeys decide to bid. If there's a second bid, the first bidder will get a 2.5% bidFine for being the first. The bidFine will also be paid if Alice decides to redeem part of the debt and make the HF go above one.

Name	Type	Description
nftAsset	address	the underlying NFT address used as collateral with HF < 1
nftTokenId	uint256	the underlying NFT token Id used as collateral with HF < 1
bidPrice	uint256	the amount that the msg.sender decides to bid needs to be higher than previous or the debt amount + 1%
onBehalfOf	address	address whom will receive the NFT in case the auction is successful

redeem

function redeem(address nftAsset, uint256 nftTokenId, uint256 amount, uint256 bidFine) external override nonReentrant whenNotPaused returns (uint256)

Redeem should be used by the NFT Owner in case the NFT goes into auction and he wants to keep his NFT.

If the auction starts and the redeem duration are still available, the user can pay an amount to increase the Health Factor.

The amount needs to be higher than the (borrowAmount * redeemThreshold)/100

Example: Alice's NFT was bid by Bob, but since Alice can still redeem, she decides to pay 70% of her debt to get the Health Factor > 1.

Call Params

Name	Type	Description
nftAsset	address	the underlying NFT address used as collateral with HF < 1 and redeemDuration available
nftTokenId	uint256	the underlying NFT token Id used as collateral with HF < 1 and redeemDuration available
amount	uint256	the amount that NFT Owner decides to pay
bidFine	uint256	the 2.5 fee the user needs to pay to the first bidder in case someone bidded during the redeemDuration

Return Values

Type	Description
uint256	paid amount + bidFine

Liquidate

function liquidate(address nftAsset, uint256 nftTokenId, uint256 amount) external override nonReentrant whenNotPaused returns (uint256)

After the auction period ends. The liquidator should trigger this so he can receive his collateral asset.

Example: Bob wins the auction. He can call this function to get his collateral (NFT) into his wallet.

Call Params

Name	Type	Description
nftAsset	address	the underlying NFT address used as collateral and bought on an auction
nftTokenId	uint256	the underlying NFT token Id used as collateral and bought on an auction
amount	uint256	the auction amount used to buy the NFT.

Return Values

Type	Description
uint256	borrowAmount - bidPrice

Buyout

function buyout(address nftAsset, uint256 nftTokenId, 
address onBehalfOf) external override nonReentrant whenNotPaused

If the health factor of the NFT falls below one, an auction will be initiated. The minimum bid amount during the auction will be the same as the debt amount. Users will have the option to buyout the NFT during the auction by clicking on the buyout button. The buyout amount of the NFT will be calculated on the smart contract and will be the highest value between the NFT valuation and its debt. To enable this function, the "approve" function to spend WETH will need to take into consideration the buyout amount.

Call Params

Name	Type	Description
nftAsset	address	the underlying NFT address used as collateral and bought on an auction
tokenId	uint256	the underlying NFT token Id used as collateral and bought on an auction
onBehalfOf	address	The address that will receive the NFT