Auditor

The Auditor is the risk management layer of the protocol; it determines how much collateral a user is required to maintain, and whether (and by how much) a user can be liquidated. Each time a user borrows from a Market, the Auditor validates his account’s liquidity to determine his health factor.

Public State Variables

ASSETS_THRESHOLD

function ASSETS_THRESHOLD() external view returns (uint256)

Maximum value the liquidator can send and still have granular control of max assets. Above this threshold, they should send type(uint256).max.

BASE_FEED

function BASE_FEED() external view returns (address)

Address that a market should have as price feed to consider as base price and avoid external price call.

TARGET_HEALTH

function TARGET_HEALTH() external view returns (uint256)

Target health factor that the account should have after it's liquidated to prevent cascade liquidations.

accountMarkets

function accountMarkets(address) external view returns (uint256)

Tracks the markets' indexes that an account has entered as collateral.

liquidationIncentive

function liquidationIncentive() external view returns (uint128 liquidator, uint128 lenders)

Liquidation incentive factors for the liquidator and the lenders of the market where the debt is repaid.

marketList

function marketList(uint256) external view returns (contract Market)

Array of all enabled markets.

markets

function markets(contract Market) external view returns (uint128 adjustFactor, uint8 decimals, uint8 index, bool isListed, contract IPriceFeed priceFeed)

Stores market parameters per each enabled market.

priceDecimals

function priceDecimals() external view returns (uint256)

Decimals that the answer of all price feeds should have.

View Methods

accountLiquidity

function accountLiquidity(address account, contract Market marketToSimulate, uint256 withdrawAmount) external view returns (uint256 sumCollateral, uint256 sumDebtPlusEffects)

Returns account's liquidity calculation.

Parameters

Name	Type	Description
account	address	account in which the liquidity will be calculated.
marketToSimulate	contract Market	market in which to simulate withdraw operation.
withdrawAmount	uint256	amount to simulate as withdraw.

Returns

Name	Type	Description
sumCollateral	uint256	sum of all collateral, already multiplied by each adjust factor (denominated in base).
sumDebtPlusEffects	uint256	sum of all debt divided by adjust factor considering withdrawal (denominated in base).

allMarkets

function allMarkets() external view returns (contract Market[])

Retrieves all markets.

Returns

Type	Description
contract Market[]	List of enabled markets.

assetPrice

function assetPrice(contract IPriceFeed priceFeed) external view returns (uint256)

Gets the asset price of a price feed.

If Chainlink's asset price is <= 0 the call is reverted.

Parameters

Name	Type	Description
priceFeed	contract IPriceFeed	address of Chainlink's Price Feed aggregator used to query the asset price.

Returns

Type	Description
uint256	The price of the asset scaled to 18-digit decimals.

calculateSeize

function calculateSeize(contract Market repayMarket, contract Market seizeMarket, address borrower, uint256 actualRepayAssets) external view returns (uint256 lendersAssets, uint256 seizeAssets)

Calculates the amount of collateral to be seized when a position is undercollateralized.

Parameters

Name	Type	Description
repayMarket	contract Market	market from where the debt will be repaid.
seizeMarket	contract Market	market from where the assets will be seized by the liquidator.
borrower	address	account in which assets are being seized.
actualRepayAssets	uint256	amount being repaid.

Returns

Name	Type	Description
lendersAssets	uint256	amount to be added for other lenders as a compensation of bad debt clearing.
seizeAssets	uint256	amount that can be seized by the liquidator.

checkLiquidation

function checkLiquidation(contract Market repayMarket, contract Market seizeMarket, address borrower, uint256 maxLiquidatorAssets) external view returns (uint256 maxRepayAssets)

Allows/rejects liquidation of assets.

This function can be called externally, but only will have effect when called from a market.

Parameters

Name	Type	Description
repayMarket	contract Market	market from where the debt is being repaid.
seizeMarket	contract Market	market from where the liquidator will seize assets.
borrower	address	address in which the assets are being liquidated.
maxLiquidatorAssets	uint256	maximum amount of debt the liquidator is willing to accept.

Returns

Name	Type	Description
maxRepayAssets	uint256	capped amount of debt the liquidator is allowed to repay.

checkSeize

function checkSeize(contract Market repayMarket, contract Market seizeMarket) external view

Allow/rejects seizing of assets.

This function can be called externally, but only will have effect when called from a market.

Parameters

Name	Type	Description
repayMarket	contract Market	market from where the debt will be repaid.
seizeMarket	contract Market	market where the assets will be seized.

checkShortfall

function checkShortfall(contract Market market, address account, uint256 amount) external view

Checks if the account has liquidity shortfall.

Parameters

Name	Type	Description
market	contract Market	address of the market where the operation will happen.
account	address	address of the account to check for possible shortfall.
amount	uint256	amount that the account wants to withdraw or transfer.

Write Methods

checkBorrow

function checkBorrow(contract Market market, address borrower) external nonpayable

Validates that the current state of the position and system are valid.

To be called after adding the borrowed debt to the account position.

Parameters

Name	Type	Description
market	contract Market	address of the market where the borrow is made.
borrower	address	address of the account that will repay the debt.

enableMarket

function enableMarket(contract Market market, contract IPriceFeed priceFeed, uint128 adjustFactor, uint8 decimals) external nonpayable

Enables a certain market.

Enabling more than 256 markets will cause an overflow when casting market index to uint8.

Parameters

Name	Type	Description
market	contract Market	market to add to the protocol.
priceFeed	contract IPriceFeed	address of Chainlink's Price Feed aggregator used to query the asset price in base.
adjustFactor	uint128	market's adjust factor for the underlying asset.
decimals	uint8	decimals of the market's underlying asset.

enterMarket

function enterMarket(contract Market market) external nonpayable

Allows assets of a certain market to be used as collateral for borrowing other assets.

Parameters

Name	Type	Description
market	contract Market	market to enabled as collateral.

exitMarket

function exitMarket(contract Market market) external nonpayable

Removes market from sender's account liquidity calculation.

Sender must not have an outstanding borrow balance in the asset, or be providing necessary collateral for an outstanding borrow.

Parameters

Name	Type	Description
market	contract Market	market to be disabled as collateral.

handleBadDebt

function handleBadDebt(address account) external nonpayable

Checks if account has debt with no collateral, if so then call clearBadDebt from each market.

Collateral is multiplied by price and adjust factor to be accurately evaluated as positive collateral asset.

Parameters

Name	Type	Description
account	address	account in which debt is being checked.