> For the complete documentation index, see [llms.txt](https://devs.unlockd.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://devs.unlockd.finance/unlockd-for-devs-v1/the-core-protocol/lendpoolloan.md). # LendPoolLoan The LendPoolLoan is called by the LendPool and does everything related to loans and collaterals. ## View Methods `function borrowerOf(uint256 loanId) external view returns (address)` Returns the address of the borrower. #### Call Params | Name | Type | Description | | ------ | ------- | ------------------ | | loanId | uint256 | the id of the loan | #### Return Values | Type | Description | | ------- | --------------------------------------------------- | | address | the `borrower` address associated with the `loanId` | ### getCollateralLoanId `function getCollateralLoanId(address nftAsset, uint256 nftTokenId) external view returns (uint256)` Returns the loan id corresponding to a specific `nftAsset` and `nftTokenId` #### Call Params | Name | Type | Description | | ---------- | ------- | ------------------------------------ | | nftAsset | address | The address of the underlying asset. | | nftTokenId | uint256 | the tokenId of the underlying asset | #### Return Values | Name | Description | | ------- | --------------------------------- | | uint256 | the loan Id for the specified NFT | ### getLoanIdTracker `function getLoanIdTracker() external view returns (struct CountersUpgradeable.Counter)` Returns the counter tracker for all the loan IDs in the protocol #### Return Values | Type | Description | | ----------------------------- | --------------------------------------------- | | `CountersUpgradeable.Counter` | the number that will be used in the next loan | ### getUserNftCollateralAmount `function getUserNftCollateralAmount(address user, address nftAsset) external view returns (uint256)` Returns the collateral amount for a given user and a specific NFT collection. #### Call Params | Name | Type | Description | | -------- | ------- | -------------------------------------------------------------- | | user | address | the address of the user we want to chech the collateral amount | | nftAsset | address | the address of the underlying asset | #### Return Values | Type | Description | | ------- | --------------------------------------------------------------- | | uint256 | the amount the user has as collateral for a specific collection | ### getNftCollateralAmount `function getNftCollateralAmount(address nftAsset) external view returns (uint256)` Returns the collateral amount for a specific collection. #### Call Params | Name | Type | Description | | -------- | ------- | ----------------------------------------------- | | nftAsset | address | the address of the underlying asset, collection | #### Return Values | Type | Description | | ------- | ----------------------------------------------- | | uint256 | the collateral amount for a specific collection | ### getLoanHighestBid `function getLoanHighestBid(uint256 loanId) external view returns (address, uint256)` Returns the address and the bid price of the highest bid during an auction. #### Call Params | Name | Type | Description | | ------ | ------- | ------------------ | | loanId | uint256 | the id of the loan | #### Return Values | Type | Description | | ------- | ------------------ | | address | the bidder address | | uint256 | the bid price | ### getLoanReserveBorrowScaledAmount `function getLoanReserveBorrowScaledAmount(uint256 loanId) external view returns (address, uint256)` Returns the scaled amount and the reserve asset for a specific loan. #### Call Params | Name | Type | Description | | ------- | ------ | ----------------------------------------------------------- | | uint256 | loanId | the loan id to retrive the scalled amount and reserve asset | #### Return Values | Type | Description | | ------- | ------------------------- | | address | the reserve asset (ERC20) | | uint256 | the scaled amount | ### getLoanReserveBorrowAmount `function getLoanReserveBorrowAmount(uint256 loanId) external view returns (address, uint256)` Returns the amount borrowed and the reserve address for a specific loan. #### Call Params | Name | Type | Description | | ------ | ------- | ------------------------------- | | loanId | uint256 | the loan id to retrive the data | #### Return Values | Type | Description | | ------- | ------------------- | | address | the reserve address | | uint256 | the amount borrowed | ### getLoanCollateralAndReserve `function getLoanCollateralAndReserve(uint256 loanId) external view returns (address nftAsset, uint256 nftTokenId, address reserveAsset, uint256 scaledAmount)` Returns the NFT address, tokenId, reserve address and scaled amount for a specific loan. #### Call Params | Name | Type | Description | | ------ | ------- | ------------------------------------------- | | loanId | uint256 | the id of the loan we want to retrive data | #### Return Values | Name | Type | Description | | ------------ | ------- | --------------------------------------------- | | nftAsset | address | the address of the underlying asset (ERC721) | | nftTokenId | uint256 | the token id of the underlying asset (ERC721) | | reserveAsset | address | the address of the reserve asset (ERC20) | | scaledAmount | uint256 | the scaled amount | ### getLoan `function getLoan(uint256 loanId) external view returns (struct DataTypes.LoanData loanData)` Returns the struct containing all the info regarding a specific loan. #### Call Params | Name | Type | Description | | ------ | ------- | -------------------------------- | | loanId | uint256 | the loan id to retrive data from | #### Return Values | Name | Type | Description | | -------- | ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | loanData | DataTypes.LoanData |

LoanData struct:
loanId,

state,

borrower,

nftAsset,

nftTokenId,

reserveAsset,

scaledAmount, bidStartTimestamp, bidderAddress,

bidPrice,

bidBorrowAmount, firstBidderAddress;

| ## Write Methods ### createLoan `function createLoan(address initiator, address onBehalfOf, address nftAsset, uint256 nftTokenId, address uNftAddress, address reserveAsset, uint256 amount, uint256 borrowIndex) external returns (uint256)` Create and store the loan, and mint the uNFT to the user as proof of deposit. #### Call Params | Name | Type | Description | | ------------ | ------- | --------------------------------------------- | | initiator | address | The address of the user initiating the borrow | | onBehalfOf | address | The address receiving the loan | | nftAsset | address | The address of the underlying NFT asset | | nftTokenId | uint256 | The token Id of the underlying NFT asset | | uNftAddress | address | The address of the uNFT token | | reserveAsset | address | The address of the underlying reserve asset | | amount | uint256 | The loan amount | | borrowIndex | uint256 | The index to get the scaled loan amount | #### Return Values | Type | Description | | ------- | ----------- | | uint256 | the loan id | ### updateLoan `function updateLoan(address initiator, uint256 loanId, uint256 amountAdded, uint256 amountTaken, uint256 borrowIndex) external` It updates an existing loan. {% hint style="info" %} The caller must be a holder of the loan. The loan must be in an active state {% endhint %} #### Call Params | Name | Type | Description | | ----------- | ------- | ----------------------------------------- | | initiator | address | The address of the user updating the loan | | loanId | uint256 | The loan ID | | amountAdded | uint256 | The amount added to the loan | | amountTaken | uint256 | The amount taken from the loan | | borrowIndex | uint256 | The index to get the scaled loan amount | ### repayLoan `function repayLoan(address initiator, uint256 loanId, address uNftAddress, uint256 amount, uint256 borrowIndex) external` It will repay the given loan, partially or in whole. {% hint style="info" %} The caller must be a holder of the loan. The caller must send in principal + interest. The loan must be in an active state. {% endhint %} #### Call Params | Name | Type | Description | | ----------- | ------- | -------------------------------------------- | | initiator | address | The address of the user initiating the repay | | loanId | uint256 | The loan getting burned | | uNftAddress | address | The address of uNFT | | amount | uint256 | The amount repaid | | borrowIndex | uint256 | The index to get the scaled loan amount | ### auctionLoan `function auctionLoan(address initiator, uint256 loanId, address onBehalfOf, uint256 bidPrice, uint256 borrowAmount, uint256 borrowIndex) external` It will start and run an auction at a given loan. {% hint style="info" %} The price must be greater than the current highest price. The loan must be in an active or auction state. {% endhint %} #### Call Params | Name | Type | Description | | ------------ | ------- | ---------------------------------------------- | | initiator | address | The address of the user initiating the auction | | loanId | uint256 | The loan getting auctioned | | onBehalfOf | address | The user address regarding the auction | | bidPrice | uint256 | The bid price of this auction | | borrowAmount | uint256 | The amount that was borrowed | | borrowIndex | uint256 | the borrow index | ### redeemLoan `function redeemLoan(address initiator, uint256 loanId, uint256 amountTaken, uint256 borrowIndex) external` If the loan is in an auction state, and the owner wants to pay it back, making the health factor go above 1. {% hint style="info" %} The caller must be a holder of the loan. The loan must be in an auction state. {% endhint %} {% hint style="danger" %} redeemLoan = auction state. repayLoan = active state. {% endhint %} #### Call Params | Name | Type | Description | | ----------- | ------- | --------------------------------------------- | | initiator | address | The address of the user initiating the borrow | | loanId | uint256 | The loan getting redeemed | | amountTaken | uint256 | The taken amount | | borrowIndex | uint256 | The index to get the scaled loan amount | ### liquidateLoan `function liquidateLoan(address initiator, uint256 loanId, address uNftAddress, uint256 borrowAmount, uint256 borrowIndex) external` Liquidate the given loan, sending the NFT to its new owner. {% hint style="info" %} The caller must send in principal + interest. The loan must be in an active state. {% endhint %} #### Call Params | Name | Type | Description | | ------------ | ------- | ---------------------------------------------- | | initiator | address | The address of the user initiating the auction | | loanId | uint256 | The loan getting burned | | uNftAddress | address | The address of uNFT | | borrowAmount | uint256 | The borrow amount | | borrowIndex | uint256 | The index to get the scaled loan amount | ### buyoutLoan `function buyoutLoan(address initiator, uint256 loanId, address uNftAddress, uint256 borrowAmount, uint256 borrowIndex, uint256 buyoutAmount) external override onlyLendPool` Will clear the borrower's debt, pay the protocol and send the NFT to the new owner. #### Call Params | Name | Type | Description | | ------------ | ------- | ----------------------------------------- | | initiator | adress | The buyers address | | loanId | uint256 | the Id that will be bought | | uNftAddress | address | the address of the uNFT (the NFT reserve) | | borrowAmount | uint256 | the debt amount | | borrowIndex | uint256 | the borrow index | | buyoutAmount | uint256 | the amount to buy the NFT | ### liquidateLoanMarket `function liquidateLoanMarket(uint256 loanId, address uNftAddress, uint256 borrowAmount, uint256 borrowIndex) external override onlyMarketAdapter` It will liquidate the NFTs in case of no bids or not enough amount in bids (compared to the markets using the reservoir adapter) when an auction is created. #### Call Params | Name | Type | Description | | ------------ | ------- | ------------------------------------------------- | | loanId | uint256 | the id of the loan | | uNftAddress | address | the uNFT address, the address for the NFT reserve | | borrowAmount | uint256 | the amount borrowed by the user | | borrowIndex | uint256 | the borrow index |