Comptroller

Comptroller

The Comptroller is designed to provide checks for all minting, redeeming, transferring, borrowing, lending, repaying, liquidating, and seizing done by the vToken contract. Each pool has one Comptroller checking these interactions across markets. When a user interacts with a given market by one of these main actions, a call is made to a corresponding hook in the associated Comptroller, which either allows or reverts the transaction. These hooks also update supply and borrow rewards as they are called. The comptroller holds the logic for assessing liquidity snapshots of an account via the collateral factor and liquidation threshold. This check determines the collateral needed for a borrow, as well as how much of a borrow may be liquidated. A user may borrow a portion of their collateral with the maximum amount determined by the markets collateral factor. However, if their borrowed amount exceeds an amount calculated using the market’s corresponding liquidation threshold, the borrow is eligible for liquidation.

The Comptroller also includes two functions liquidateAccount() and healAccount(), which are meant to handle accounts that do not exceed the minLiquidatableCollateral for the Comptroller:

  • healAccount(): This function is called to seize all of a given user’s collateral, requiring the msg.sender repay a certain percentage of the debt calculated by collateral/(borrows*liquidationIncentive). The function can only be called if the calculated percentage does not exceed 100%, because otherwise no badDebt would be created and liquidateAccount() should be used instead. The difference in the actual amount of debt and debt paid off is recorded as badDebt for each market, which can then be auctioned off for the risk reserves of the associated pool.

  • liquidateAccount(): This function can only be called if the collateral seized will cover all borrows of an account, as well as the liquidation incentive. Otherwise, the pool will incur bad debt, in which case the function healAccount() should be used instead. This function skips the logic verifying that the repay amount does not exceed the close factor.

Solidity API

enterMarkets

Add assets to be included in account liquidity calculation; enabling them to be used as collateral

function enterMarkets(address[] vTokens) external returns (uint256[])

Parameters

NameTypeDescription

vTokens

address[]

The list of addresses of the vToken markets to be enabled

Return Values

NameTypeDescription

[0]

uint256[]

errors An array of NO_ERROR for compatibility with Venus core tooling

πŸ“… Events

  • MarketEntered is emitted for each market on success

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if entering any of the markets is paused

  • MarketNotListed error is thrown if any of the markets is not listed


updateDelegate

Grants or revokes the borrowing delegate rights to / from an account If allowed, the delegate will be able to borrow funds on behalf of the sender Upon a delegated borrow, the delegate will receive the funds, and the borrower will see the debt on their account

function updateDelegate(address delegate, bool allowBorrows) external

Parameters

NameTypeDescription

delegate

address

The address to update the rights for

allowBorrows

bool

Whether to grant (true) or revoke (false) the rights

πŸ“… Events

  • DelegateUpdated emits on success

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ZeroAddressNotAllowed is thrown when delegate address is zero


exitMarket

Removes asset from sender's account liquidity calculation; disabling them as collateral

function exitMarket(address vTokenAddress) external returns (uint256)

Parameters

NameTypeDescription

vTokenAddress

address

The address of the asset to be removed

Return Values

NameTypeDescription

[0]

uint256

error Always NO_ERROR for compatibility with Venus core tooling

πŸ“… Events

  • MarketExited is emitted on success

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if exiting the market is paused

  • NonzeroBorrowBalance error is thrown if the user has an outstanding borrow in this market

  • MarketNotListed error is thrown when the market is not listed

  • InsufficientLiquidity error is thrown if exiting the market would lead to user's insolvency

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


preMintHook

Checks if the account should be allowed to mint tokens in the given market

function preMintHook(address vToken, address minter, uint256 mintAmount) external

Parameters

NameTypeDescription

vToken

address

The market to verify the mint against

minter

address

The account which would get the minted tokens

mintAmount

uint256

The amount of underlying being supplied to the market in exchange for tokens

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if supplying to this market is paused

  • MarketNotListed error is thrown when the market is not listed

  • SupplyCapExceeded error is thrown if the total supply exceeds the cap after minting


mintVerify

Validates mint, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function mintVerify(address vToken, address minter, uint256 actualMintAmount, uint256 mintTokens) external

Parameters

NameTypeDescription

vToken

address

Asset being minted

minter

address

The address minting the tokens

actualMintAmount

uint256

The amount of the underlying asset being minted

mintTokens

uint256

The number of tokens being minted


preRedeemHook

Checks if the account should be allowed to redeem tokens in the given market

function preRedeemHook(address vToken, address redeemer, uint256 redeemTokens) external

Parameters

NameTypeDescription

vToken

address

The market to verify the redeem against

redeemer

address

The account which would redeem the tokens

redeemTokens

uint256

The number of vTokens to exchange for the underlying asset in the market

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if withdrawals are paused in this market

  • MarketNotListed error is thrown when the market is not listed

  • InsufficientLiquidity error is thrown if the withdrawal would lead to user's insolvency

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


redeemVerify

Validates redeem, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function redeemVerify(address vToken, address redeemer, uint256 redeemAmount, uint256 redeemTokens) external

Parameters

NameTypeDescription

vToken

address

Asset being redeemed

redeemer

address

The address redeeming the tokens

redeemAmount

uint256

The amount of the underlying asset being redeemed

redeemTokens

uint256

The number of tokens being redeemed


repayBorrowVerify

Validates repayBorrow, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function repayBorrowVerify(address vToken, address payer, address borrower, uint256 actualRepayAmount, uint256 borrowerIndex) external

Parameters

NameTypeDescription

vToken

address

Asset being repaid

payer

address

The address repaying the borrow

borrower

address

The address of the borrower

actualRepayAmount

uint256

The amount of underlying being repaid

borrowerIndex

uint256


liquidateBorrowVerify

Validates liquidateBorrow, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function liquidateBorrowVerify(address vTokenBorrowed, address vTokenCollateral, address liquidator, address borrower, uint256 actualRepayAmount, uint256 seizeTokens) external

Parameters

NameTypeDescription

vTokenBorrowed

address

Asset which was borrowed by the borrower

vTokenCollateral

address

Asset which was used as collateral and will be seized

liquidator

address

The address repaying the borrow and seizing the collateral

borrower

address

The address of the borrower

actualRepayAmount

uint256

The amount of underlying being repaid

seizeTokens

uint256

The amount of collateral token that will be seized


seizeVerify

Validates seize, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function seizeVerify(address vTokenCollateral, address vTokenBorrowed, address liquidator, address borrower, uint256 seizeTokens) external

Parameters

NameTypeDescription

vTokenCollateral

address

Asset which was used as collateral and will be seized

vTokenBorrowed

address

Asset which was borrowed by the borrower

liquidator

address

The address repaying the borrow and seizing the collateral

borrower

address

The address of the borrower

seizeTokens

uint256

The number of collateral tokens to seize


transferVerify

Validates transfer, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function transferVerify(address vToken, address src, address dst, uint256 transferTokens) external

Parameters

NameTypeDescription

vToken

address

Asset being transferred

src

address

The account which sources the tokens

dst

address

The account which receives the tokens

transferTokens

uint256

The number of vTokens to transfer


preBorrowHook

disable-eslint

function preBorrowHook(address vToken, address borrower, uint256 borrowAmount) external

borrowVerify

Validates borrow, accrues interest and updates score in prime. Reverts on rejection. May emit logs.

function borrowVerify(address vToken, address borrower, uint256 borrowAmount) external

Parameters

NameTypeDescription

vToken

address

Asset whose underlying is being borrowed

borrower

address

The address borrowing the underlying

borrowAmount

uint256

The amount of the underlying asset requested to borrow


preRepayHook

Checks if the account should be allowed to repay a borrow in the given market

function preRepayHook(address vToken, address borrower) external

Parameters

NameTypeDescription

vToken

address

The market to verify the repay against

borrower

address

The account which would borrowed the asset

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if repayments are paused in this market

  • MarketNotListed error is thrown when the market is not listed


preLiquidateHook

Checks if the liquidation should be allowed to occur

function preLiquidateHook(address vTokenBorrowed, address vTokenCollateral, address borrower, uint256 repayAmount, bool skipLiquidityCheck) external

Parameters

NameTypeDescription

vTokenBorrowed

address

Asset which was borrowed by the borrower

vTokenCollateral

address

Asset which was used as collateral and will be seized

borrower

address

The address of the borrower

repayAmount

uint256

The amount of underlying being repaid

skipLiquidityCheck

bool

Allows the borrow to be liquidated regardless of the account liquidity

❌ Errors

  • ActionPaused error is thrown if liquidations are paused in this market

  • MarketNotListed error is thrown if either collateral or borrowed token is not listed

  • TooMuchRepay error is thrown if the liquidator is trying to repay more than allowed by close factor

  • MinimalCollateralViolated is thrown if the users' total collateral is lower than the threshold for non-batch liquidations

  • InsufficientShortfall is thrown when trying to liquidate a healthy account

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


preSeizeHook

Checks if the seizing of assets should be allowed to occur

function preSeizeHook(address vTokenCollateral, address seizerContract, address liquidator, address borrower) external

Parameters

NameTypeDescription

vTokenCollateral

address

Asset which was used as collateral and will be seized

seizerContract

address

Contract that tries to seize the asset (either borrowed vToken or Comptroller)

liquidator

address

The address repaying the borrow and seizing the collateral

borrower

address

The address of the borrower

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if seizing this type of collateral is paused

  • MarketNotListed error is thrown if either collateral or borrowed token is not listed

  • ComptrollerMismatch error is when seizer contract or seized asset belong to different pools


preTransferHook

Checks if the account should be allowed to transfer tokens in the given market

function preTransferHook(address vToken, address src, address dst, uint256 transferTokens) external

Parameters

NameTypeDescription

vToken

address

The market to verify the transfer against

src

address

The account which sources the tokens

dst

address

The account which receives the tokens

transferTokens

uint256

The number of vTokens to transfer

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • ActionPaused error is thrown if withdrawals are paused in this market

  • MarketNotListed error is thrown when the market is not listed

  • InsufficientLiquidity error is thrown if the withdrawal would lead to user's insolvency

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


healAccount

Seizes all the remaining collateral, makes msg.sender repay the existing borrows, and treats the rest of the debt as bad debt (for each market). The sender has to repay a certain percentage of the debt, computed as collateral / (borrows * liquidationIncentive).

function healAccount(address user) external

Parameters

NameTypeDescription

user

address

account to heal

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • CollateralExceedsThreshold error is thrown when the collateral is too big for healing

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


liquidateAccount

Liquidates all borrows of the borrower. Callable only if the collateral is less than a predefined threshold, and the account collateral can be seized to cover all borrows. If the collateral is higher than the threshold, use regular liquidations. If the collateral is below the threshold, and the account is insolvent, use healAccount.

function liquidateAccount(address borrower, struct ComptrollerStorage.LiquidationOrder[] orders) external

Parameters

NameTypeDescription

borrower

address

the borrower address

orders

struct ComptrollerStorage.LiquidationOrder[]

an array of liquidation orders

⛔️ Access Requirements

  • Not restricted

❌ Errors

  • CollateralExceedsThreshold error is thrown when the collateral is too big for a batch liquidation

  • InsufficientCollateral error is thrown when there is not enough collateral to cover the debt

  • SnapshotError is thrown if some vToken fails to return the account's supply and borrows

  • PriceError is thrown if the oracle returns an incorrect price for some asset


setCloseFactor

Sets the closeFactor to use when liquidating borrows

function setCloseFactor(uint256 newCloseFactorMantissa) external

Parameters

NameTypeDescription

newCloseFactorMantissa

uint256

New close factor, scaled by 1e18

πŸ“… Events

  • Emits NewCloseFactor on success

⛔️ Access Requirements

  • Controlled by AccessControlManager


setCollateralFactor

Sets the collateralFactor for a market

function setCollateralFactor(contract VToken vToken, uint256 newCollateralFactorMantissa, uint256 newLiquidationThresholdMantissa) external

Parameters

NameTypeDescription

vToken

contract VToken

The market to set the factor on

newCollateralFactorMantissa

uint256

The new collateral factor, scaled by 1e18

newLiquidationThresholdMantissa

uint256

The new liquidation threshold, scaled by 1e18

πŸ“… Events

  • Emits NewCollateralFactor when collateral factor is updated

  • and NewLiquidationThreshold when liquidation threshold is updated

⛔️ Access Requirements

  • Controlled by AccessControlManager

❌ Errors

  • MarketNotListed error is thrown when the market is not listed

  • InvalidCollateralFactor error is thrown when collateral factor is too high

  • InvalidLiquidationThreshold error is thrown when liquidation threshold is lower than collateral factor

  • PriceError is thrown when the oracle returns an invalid price for the asset


setLiquidationIncentive

Sets liquidationIncentive

function setLiquidationIncentive(uint256 newLiquidationIncentiveMantissa) external

Parameters

NameTypeDescription

newLiquidationIncentiveMantissa

uint256

New liquidationIncentive scaled by 1e18

πŸ“… Events

  • Emits NewLiquidationIncentive on success

⛔️ Access Requirements

  • Controlled by AccessControlManager


supportMarket

Add the market to the markets mapping and set it as listed

function supportMarket(contract VToken vToken) external

Parameters

NameTypeDescription

vToken

contract VToken

The address of the market (token) to list

⛔️ Access Requirements

  • Only PoolRegistry

❌ Errors

  • MarketAlreadyListed is thrown if the market is already listed in this pool


setMarketBorrowCaps

Set the given borrow caps for the given vToken markets. Borrowing that brings total borrows to or above borrow cap will revert.

function setMarketBorrowCaps(contract VToken[] vTokens, uint256[] newBorrowCaps) external

Parameters

NameTypeDescription

vTokens

contract VToken[]

The addresses of the markets (tokens) to change the borrow caps for

newBorrowCaps

uint256[]

The new borrow cap values in underlying to be set. A value of type(uint256).max corresponds to unlimited borrowing.

⛔️ Access Requirements

  • Controlled by AccessControlManager


setMarketSupplyCaps

Set the given supply caps for the given vToken markets. Supply that brings total Supply to or above supply cap will revert.

function setMarketSupplyCaps(contract VToken[] vTokens, uint256[] newSupplyCaps) external

Parameters

NameTypeDescription

vTokens

contract VToken[]

The addresses of the markets (tokens) to change the supply caps for

newSupplyCaps

uint256[]

The new supply cap values in underlying to be set. A value of type(uint256).max corresponds to unlimited supply.

⛔️ Access Requirements

  • Controlled by AccessControlManager


setActionsPaused

Pause/unpause specified actions

function setActionsPaused(contract VToken[] marketsList, enum ComptrollerStorage.Action[] actionsList, bool paused) external

Parameters

NameTypeDescription

marketsList

contract VToken[]

Markets to pause/unpause the actions on

actionsList

enum ComptrollerStorage.Action[]

List of action ids to pause/unpause

paused

bool

The new paused state (true=paused, false=unpaused)

⛔️ Access Requirements

  • Controlled by AccessControlManager


setMinLiquidatableCollateral

Set the given collateral threshold for non-batch liquidations. Regular liquidations will fail if the collateral amount is less than this threshold. Liquidators should use batch operations like liquidateAccount or healAccount.

function setMinLiquidatableCollateral(uint256 newMinLiquidatableCollateral) external

Parameters

NameTypeDescription

newMinLiquidatableCollateral

uint256

The new min liquidatable collateral (in USD).

⛔️ Access Requirements

  • Controlled by AccessControlManager


addRewardsDistributor

Add a new RewardsDistributor and initialize it with all markets. We can add several RewardsDistributor contracts with the same rewardToken, and there could be overlaping among them considering the last reward block

function addRewardsDistributor(contract RewardsDistributor _rewardsDistributor) external

Parameters

NameTypeDescription

_rewardsDistributor

contract RewardsDistributor

Address of the RewardDistributor contract to add

πŸ“… Events

  • Emits NewRewardsDistributor with distributor address

⛔️ Access Requirements

  • Only Governance


setPriceOracle

Sets a new price oracle for the Comptroller

function setPriceOracle(contract ResilientOracleInterface newOracle) external

Parameters

NameTypeDescription

newOracle

contract ResilientOracleInterface

Address of the new price oracle to set

πŸ“… Events

  • Emits NewPriceOracle on success

❌ Errors

  • ZeroAddressNotAllowed is thrown when the new oracle address is zero


setMaxLoopsLimit

Set the for loop iteration limit to avoid DOS

function setMaxLoopsLimit(uint256 limit) external

Parameters

NameTypeDescription

limit

uint256

Limit for the max loops can execute at a time


setPrimeToken

Sets the prime token contract for the comptroller

function setPrimeToken(contract IPrime _prime) external

Parameters

NameTypeDescription

_prime

contract IPrime

Address of the Prime contract


setForcedLiquidation

Enables forced liquidations for a market. If forced liquidation is enabled, borrows in the market may be liquidated regardless of the account liquidity

function setForcedLiquidation(address vTokenBorrowed, bool enable) external

Parameters

NameTypeDescription

vTokenBorrowed

address

Borrowed vToken

enable

bool

Whether to enable forced liquidations


getAccountLiquidity

Determine the current account liquidity with respect to liquidation threshold requirements

function getAccountLiquidity(address account) external view returns (uint256 error, uint256 liquidity, uint256 shortfall)

Parameters

NameTypeDescription

account

address

The account get liquidity for

Return Values

NameTypeDescription

error

uint256

Always NO_ERROR for compatibility with Venus core tooling

liquidity

uint256

Account liquidity in excess of liquidation threshold requirements,

shortfall

uint256

Account shortfall below liquidation threshold requirements


getBorrowingPower

Determine the current account liquidity with respect to collateral requirements

function getBorrowingPower(address account) external view returns (uint256 error, uint256 liquidity, uint256 shortfall)

Parameters

NameTypeDescription

account

address

The account get liquidity for

Return Values

NameTypeDescription

error

uint256

Always NO_ERROR for compatibility with Venus core tooling

liquidity

uint256

Account liquidity in excess of collateral requirements,

shortfall

uint256

Account shortfall below collateral requirements


getHypotheticalAccountLiquidity

Determine what the account liquidity would be if the given amounts were redeemed/borrowed

function getHypotheticalAccountLiquidity(address account, address vTokenModify, uint256 redeemTokens, uint256 borrowAmount) external view returns (uint256 error, uint256 liquidity, uint256 shortfall)

Parameters

NameTypeDescription

account

address

The account to determine liquidity for

vTokenModify

address

The market to hypothetically redeem/borrow in

redeemTokens

uint256

The number of tokens to hypothetically redeem

borrowAmount

uint256

The amount of underlying to hypothetically borrow

Return Values

NameTypeDescription

error

uint256

Always NO_ERROR for compatibility with Venus core tooling

liquidity

uint256

Hypothetical account liquidity in excess of collateral requirements,

shortfall

uint256

Hypothetical account shortfall below collateral requirements


getAllMarkets

Return all of the markets

function getAllMarkets() external view returns (contract VToken[])

Return Values

NameTypeDescription

[0]

contract VToken[]

markets The list of market addresses


isMarketListed

Check if a market is marked as listed (active)

function isMarketListed(contract VToken vToken) external view returns (bool)

Parameters

NameTypeDescription

vToken

contract VToken

vToken Address for the market to check

Return Values

NameTypeDescription

[0]

bool

listed True if listed otherwise false


getAssetsIn

Returns the assets an account has entered

function getAssetsIn(address account) external view returns (contract VToken[])

Parameters

NameTypeDescription

account

address

The address of the account to pull assets for

Return Values

NameTypeDescription

[0]

contract VToken[]

A list with the assets the account has entered


checkMembership

Returns whether the given account is entered in a given market

function checkMembership(address account, contract VToken vToken) external view returns (bool)

Parameters

NameTypeDescription

account

address

The address of the account to check

vToken

contract VToken

The vToken to check

Return Values

NameTypeDescription

[0]

bool

True if the account is in the market specified, otherwise false.


liquidateCalculateSeizeTokens

Calculate number of tokens of collateral asset to seize given an underlying amount

function liquidateCalculateSeizeTokens(address vTokenBorrowed, address vTokenCollateral, uint256 actualRepayAmount) external view returns (uint256 error, uint256 tokensToSeize)

Parameters

NameTypeDescription

vTokenBorrowed

address

The address of the borrowed vToken

vTokenCollateral

address

The address of the collateral vToken

actualRepayAmount

uint256

The amount of vTokenBorrowed underlying to convert into vTokenCollateral tokens

Return Values

NameTypeDescription

error

uint256

Always NO_ERROR for compatibility with Venus core tooling

tokensToSeize

uint256

Number of vTokenCollateral tokens to be seized in a liquidation

❌ Errors

  • PriceError if the oracle returns an invalid price


getRewardsByMarket

Returns reward speed given a vToken

function getRewardsByMarket(address vToken) external view returns (struct ComptrollerStorage.RewardSpeeds[] rewardSpeeds)

Parameters

NameTypeDescription

vToken

address

The vToken to get the reward speeds for

Return Values

NameTypeDescription

rewardSpeeds

struct ComptrollerStorage.RewardSpeeds[]

Array of total supply and borrow speeds and reward token for all reward distributors


getRewardDistributors

Return all reward distributors for this pool

function getRewardDistributors() external view returns (contract RewardsDistributor[])

Return Values

NameTypeDescription

[0]

contract RewardsDistributor[]

Array of RewardDistributor addresses


isComptroller

A marker method that returns true for a valid Comptroller contract

function isComptroller() external pure returns (bool)

Return Values

NameTypeDescription

[0]

bool

Always true


updatePrices

Update the prices of all the tokens associated with the provided account

function updatePrices(address account) public

Parameters

NameTypeDescription

account

address

Address of the account to get associated tokens with


actionPaused

Checks if a certain action is paused on a market

function actionPaused(address market, enum ComptrollerStorage.Action action) public view returns (bool)

Parameters

NameTypeDescription

market

address

vToken address

action

enum ComptrollerStorage.Action

Action to check

Return Values

NameTypeDescription

[0]

bool

paused True if the action is paused otherwise false


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