View Contracts

The Nexus Protocol has several view contracts to assist with querying on chain data.

UiPoolDataProvider

Contract that returns an array of all reserve or user data for a particular market (for example, liquidity, token addresses, rate strategy), used by the Nexus Interface to display Markets and Dashboard data.

The Utilities SDK includes an interface to make calls to this contract, and functions to format the response for frontend use-cases.

The source code is available on GitHub.

View Methods

getReservesList

function getReservesList(IPoolAddressesProvider provider) public view override returns (address[] memory)

Returns the list of initialised reserves in the Pool associated with the given provider.

Input Parameters:

Name	Type	Description
provider	IPoolAddressesProvider	The given provider for the associated pool

Return Values:

Type	Description
address[]	The list of initialised reserves in the Pool

getReservesData

function getReservesData(IPoolAddressesProvider provider) public view override returns (AggregatedReserveData[] memory, BaseCurrencyInfo memory)

Returns BaseCurrencyInfo of the Pool and AggregatedReserveData[] for all the initialised reserves in the Pool associated with the given provider.

Input Parameters:

Name	Type	Description
provider	IPoolAddressesProvider	The given provider for the associated pool

Return Values:

Type	Description
BaseCurrencyInfo	The base currency information
AggregatedReserveData[]	The aggregated reserve data

The BaseCurrencyInfo struct is composed of the following fields:

marketReferenceCurrencyUnit	uint256	Reference aka base currency of the Nexus market
marketReferenceCurrencyPriceInUsd	int256	Price of reference aka base currency in USD
networkBaseTokenPriceInUsd	int256	Price of native token of the network/chain in USD
networkBaseTokenPriceDecimals	uint8	Decimals of native token of the network/chain

The AggregatedReserveData struct is composed of the following fields:

Name	Type	Description
underlyingAsset	address	The address of the underlying asset of the reserve
name	string	The name of the underlying reserve asset
symbol	string	The symbol of the underlying reserve asset
decimals	uint256	The number of decimals of the reserve
baseLTVasCollateral	uint256	The ltv of the reserve
reserveLiquidationThreshold	uint256	The liquidation threshold of the reserve
reserveLiquidationBonus	uint256	The liquidation bonus of the resurve
reserveFactor	uint256	The reserve factor of the reserve
usageAsCollateralEnabled	bool	true if the asset is enabled to be used as collateral, false otherwise
borrowingEnabled	bool	true if borrowing is enabled, false otherwise
isActive	bool	true if reserve is active, false otherwise
isFrozen	bool	true if reserve is frozen, false otherwise
BASE DATA
liquidityIndex	uint128	The liquidity index of the reserve
variableBorrowIndex	uint128	The variable borrow index of the reserve
liquidityRate	uint128	The liquidity rate of the reserve
variableBorrowRate	uint128	The variable borrow rate of the reserve
lastUpdateTimestamp	uint40	The timestamp of the last update of the reserve
zTokenAddress	address	The ZToken address of the reserve
variableDebtTokenAddress	address	The VariableDebtToken address of the reserve
interestRateStrategyAddress	address	The address of the Interest Rate strategy
availableLiquidity	uint256	The liquidity available
totalScaledVariableDebt	uint256	The total scaled variable debt
priceInMarketReferenceCurrency	uint256	Price of reference aka base currency of Nexus market
priceOracle	address	The address of the price oracle used by the associated market
variableRateSlope1	uint256	The variable rate slope
variableRateSlope2	uint256	The variable rate slope
baseVariableBorrowRate	uint256	The base variable borrow rate, expressed in ray
optimalUsageRatio	uint256	The optimal usage ratio

getUserReservesData

function getUserReservesData(IPoolAddressesProvider provider, address user) external view override returns (UserReserveData[] memory, uint8)

Returns UserReserveData[] for all user reserves in the Pool associated with the given provider.

Input Parameters:

Name	Type	Description
provider	IPoolAddressesProvider	The given provider for the associated pool
user	address	The address of the user

UserReserveData

Type	Description
UserReserveData[]	The user reserve data

The UserReserveData struct is composed of the following fields:

Name	Type	Description
underlyingAsset	address	The address of the underlying asset supplied/borrowed
scaledZTokenBalance	uint256	The scaled balance of the zToken. scaledBalance = balance/liquidityIndex
usageAsCollateralEnabledOnUser	bool	true if the supplied asset is enabled to be used as collateral, false otherwise
scaledVariableDebt	uint256	The scaled balance of borrow position: (current balance = scaled balance * liquidity index)

WalletBalanceProvider

Fetches tokens balances for all underlying tokens of Nexus reserves for one user address.

This contract is not used within the Nexus Protocol. It is an accessory contract used to reduce the number of calls towards the blockchain from the Nexus backend.

For getting ETH (native chain token) balance use MOCK_ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE.

The source code is available on GitHub.

View Methods

balanceOf

function balanceOf(address user, address token) public view returns (uint256)

Checks the token balance of a wallet in a token contract. Returns the balance of the token for user (ETH included with MOCK_ETH_ADDRESS).

Input Parameters:

Name	Type	Description
user	address	The address of the user
token	address	The address of the token

Return Values:

Type	Description
uint256	The balance of the token for user. Returns 0 for a non-contract address

batchBalanceOf

function batchBalanceOf(address[] calldata users, address[] calldata tokens) external view returns (uint256[] memory)

Returns balances for a list of users and tokens (ETH included with MOCK_ETH_ADDRESS).

Input Parameters:

Name	Type	Description
users	address[]	The list of users
tokens	address[]	The list of tokens

Return Values:

Type	Description
uint256[]	A list of balances for each user

getUserWalletBalances

function getUserWalletBalances(address provider, address user) external view returns (address[] memory, uint256[] memory)

Provides balances of user wallet for all reserves available on the pool.

Input Parameters:

Name	Type	Description
provider	address	The address of the provider
user	address	The address of the user

Return Values:

address[]	A list of user wallets
uint256[]	A list of balances for each user

NexusProtocolDataProvider

The NexusProtocolDataProvider is a peripheral contract to collect and pre-process information from the Pool. This contract contains methods for querying token addresses, reserve parameters, and user account information. The methods of the PoolDataProvider are more granular than the UiPoolDataProvider, which queries data for reserve tokens or user balances simultaneously.

The source code is available on GitHub.

View Methods

getAllReservesTokens

function getAllReservesTokens() external view returns (TokenData[] memory)

Returns a list of the existing reserves in the pool, pairs include the symbol and tokenAddress. Handles ETH in a different way since they do not have standard symbol functions.

Return Values:

Type	Description
TokenData[]	The list of reserves, pairs of symbols and addresses

The TokenData struct is composed of the following fields:

Name	Type	Description
symbol	string	The symbol of the underlying reserve asset
tokenAddress	address	The address of the underlying reserve asset

getAllZTokens

function getAllZTokens() external view returns (TokenData[] memory)

Returns a list of the existing ZTokens in the pool, pairs include the symbol and tokenAddress.

Return Values:

Type	Description
TokenData[]	The list of ZTokens, pairs of symbols and addresses

The TokenData struct is composed of the following fields:

Name	Type	Description
symbol	string	The symbol of zToken of the reserve
tokenAddress	address	The address of zToken of the reserve

getReserveConfigurationData

function getReserveConfigurationData(address asset) external view returns (    uint256 decimals,    uint256 ltv,    uint256 liquidationThreshold,    uint256 liquidationBonus,    uint256 reserveFactor,    bool usageAsCollateralEnabled,    bool borrowingEnabled,    bool stableBorrowRateEnabled,    bool isActive,    bool isFrozen)

Returns the configuration data of the reserve as described below. Does not return borrow and supply caps, nor pause flag for compatibility.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Name	Type	Description
decimals	uint256	The number of decimals of the reserve
ltv	uint256	The ltv of the reserve
liquidationThreshold	uint256	The liquidation threshold of the reserve
liquidationBonus	uint256	The liquidation bonus of the reserve
reserveFactor	uint256	The reserve factor of the reserve
usageAsCollateralEnabled	bool	true if the usage as collateral is enabled, false otherwise
borrowingEnabled	bool	true if borrowing is enabled, false otherwise
stableBorrowRateEnabled	bool	Always false (deprecated)
isActive	bool	true if reserve is active, false otherwise
isFrozen	bool	true if reserve is frozen, false otherwise

getPaused

function getPaused(address asset) external view returns (bool isPaused)

Returns true if the pool isPaused.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Name	Type	Description
isPaused	bool	true if the pool is paused, false otherwise

getLiquidationProtocolFee

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

Returns the protocol fee on the liquidation bonus.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Type	Description
uint256	The protocol fee on liquidation

getReserveData

function getReserveData(address asset) external view override returns (    uint256 unbacked,    uint256 accruedToTreasuryScaled,    uint256 totalZToken,    uint256 totalStableDebt,    uint256 totalVariableDebt,    uint256 liquidityRate,    uint256 variableBorrowRate,    uint256 stableBorrowRate,    uint256 averageStableBorrowRate,    uint256 liquidityIndex,    uint256 variableBorrowIndex,    uint40 lastUpdateTimestamp)

Returns the reserve data.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Name	Type	Description
unbacked	uint256	The amount of unbacked zTokens of the reserve
accruedToTreasuryScaled	uint256	The scaled amount of tokens accrued to treasury that is to be minted
totalZToken	uint256	The total supply of the zToken
totalStableDebt	uint256	The total stable debt of the reserve (deprecated)
totalVariableDebt	uint256	The total variable debt of the reserve
liquidityRate	uint256	The liquidity rate of the reserve
variableBorrowRate	uint256	The variable borrow rate of the reserve
stableBorrowRate	uint256	The stable borrow rate of the reserve (deprecated)
averageStableBorrowRate	uint256	The average stable borrow rate of the reserve (deprecated)
liquidityIndex	uint256	The liquidity index of the reserve
variableBorrowIndex	uint256	The variable borrow index of the reserve
lastUpdateTimestamp	uint40	The timestamp of the last update of the reserve

getZTokenTotalSupply

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

Returns the total supply of zTokens for a given asset.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Type	Description
uint256	The total supply of the zToken

getTotalDebt

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

Returns the total debt for a given asset.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Type	Description
uint256	The total borrows for an asset

getUserReserveData

function getUserReserveData(address asset, address user) external view returns (    uint256 currentZTokenBalance,    uint256 currentStableDebt,    uint256 currentVariableDebt,    uint256 principalStableDebt,    uint256 scaledVariableDebt,    uint256 stableBorrowRate,    uint256 liquidityRate,    uint40 stableRateLastUpdated,    bool usageAsCollateralEnabled)

Returns the following user reserve data.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve
user	address	The address of the user

Return Values:

Name	Type	Description
currentZTokenBalance	uint256	The current ZToken balance of the user
currentStableDebt	uint256	The current stable debt of the user (deprecated)
currentVariableDebt	uint256	The current variable debt of the user
principalStableDebt	uint256	The principal stable debt of the user (deprecated)
scaledVariableDebt	uint256	The scaled variable debt of the user
stableBorrowRate	uint256	The stable borrow rate of the user (deprecated)
liquidityRate	uint256	The liquidity rate of the reserve
stableRateLastUpdated	uint40	The timestamp of the last update of the user stable rate (deprecated)
usageAsCollateralEnabled	bool	true if the user is using the asset as collateral, else false

getReserveTokensAddresses

function getReserveTokensAddresses(address asset) external view override returns (    address zTokenAddress,    address stableDebtTokenAddress,    address variableDebtTokenAddress)

Returns the addresses of the ZToken, stableDebtToken and variableDebtToken of the reserve.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Name	Type	Description
zTokenAddress	address	The ZToken address of the reserve
stableDebtTokenAddress	address	The StableDebtToken address of the reserve (deprecated)
variableDebtTokenAddress	address	The VariableDebtToken address of the reserve

getInterestRateStrategyAddress

function getInterestRateStrategyAddress(address asset) external view override returns (address irStrategyAddress)

Returns the address of the Interest Rate strategy.

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Name	Type	Description
irStrategyAddress	address	The address of the Interest Rate strategy

getReserveDeficit

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

Input Parameters:

Name	Type	Description
asset	address	The address of the underlying asset of the reserve

Return Values:

Type	Description
uint256	Current reserve deficit from undercollateralized borrow positions

Pure Methods

getDebtCeilingDecimals

function getDebtCeilingDecimals() external pure override returns (uint256)

Returns the debt ceiling decimals.

Return Values:

Type	Description
uint256	The debt ceiling decimals

LiquidationDataProvider

This contract is a utility for fetching and pre-processing liquidation-related parameters for a given user. It aggregates data from the underlying Pool and Price Oracle to determine a user’s position, collateral, borrow details, and liquidation limits according to the protocol parameters.

The source code is available on GitHub.

View Methods

getUserPositionFullInfo

getUserPositionFullInfo(address user) public view override returns (UserPositionFullInfo memory)

Returns aggregated position information for a user including total collateral, total debt, available borrows, current liquidation threshold, loan-to-value (LTV), and health factor. All values are denominated in the base currency.

Input Parameters:

Name	Type	Description
user	address	The address of the user whose position is queried

Return Values:

Name	Type	Description
UserPositionFullInfo	struct	The aggregated position information of the user

The UserPositionFullInfo struct is composed of the following fields:

Name	Type	Description
totalCollateralInBaseCurrency	uint256	Total collateral in base currency
totalDebtInBaseCurrency	uint256	Total debt in base currency
availableBorrowsInBaseCurrency	uint256	Available borrows in base currency
currentLiquidationThreshold	uint256	Current liquidation threshold
ltv	uint256	Loan-to-value ratio
healthFactor	uint256	Health factor of the user’s position

getCollateralFullInfo

getCollateralFullInfo(address user, address collateralAsset) external view override returns (CollateralFullInfo memory)

Returns detailed information regarding a user’s collateral for a given asset. The returned struct includes the asset’s unit (based on decimals), its current price (via the Price Oracle), the associated zToken address, the raw collateral balance, and its equivalent value in the base currency.

Input Parameters:

Name	Type	Description
user	address	The address of the user
collateralAsset	address	The address of the collateral asset to fetch information for

Return Values:

CollateralFullInfo	struct	Detailed collateral information for the specified asset

The CollateralFullInfo struct is composed of the following fields:

Name	Type	Description
assetUnit	uint256	The unit value of the asset (10^decimals)
price	uint256	Current price of the asset from the Price Oracle
zToken	address	Address of the zToken associated with the asset
collateralBalance	uint256	The raw collateral balance of the user
collateralBalanceInBaseCurrency	uint256	Collateral balance denominated in the base currency

getDebtFullInfo

getDebtFullInfo(address user, address debtAsset) external view override returns (DebtFullInfo memory)

Returns detailed information regarding a user’s debt for a given asset. The returned struct includes the asset’s unit, current price, the associated variable debt token address, the debt balance, and its equivalent value in the base currency.

Input Parameters:

Name	Type	Description
user	address	The address of the user
debtAsset	address	The address of the debt asset to fetch information for

Return Values:

Name	Type	Description
DebtFullInfo	struct	Detailed debt information for the specified asset

The DebtFullInfo struct is composed of the following fields:

assetUnit	uint256	The unit value of the asset (10^decimals)
price	uint256	Current price of the asset from the Price Oracle
variableDebtToken	address	Address of the variable debt token associated with the asset
debtBalance	uint256	The raw debt balance of the user
debtBalanceInBaseCurrency	uint256	Debt balance denominated in the base currency

getLiquidationInfo (without custom debt amount)

getLiquidationInfo(address user, address collateralAsset, address debtAsset) public view override returns (LiquidationInfo memory)

A convenience function that returns liquidation parameters for a user using the maximum possible debt liquidation amount. Internally, it calls the overloaded version with debtLiquidationAmount set to the maximum (type(uint256).max).

Input Parameters:

Name	Type	Description
user	address	The address of the user
collateralAsset	address	The address of the collateral asset
debtAsset	address	The address of the debt asset

Return Values:

Name	Type	Description
LiquidationInfo	struct	Detailed liquidation information for the specified user and assets

The LiquidationInfo struct is composed of the following fields:

Name	Type	Description
userInfo	struct	Aggregated position details of the user (UserPositionFullInfo above)
collateralInfo	struct	Detailed collateral information (CollateralFullInfo above)
debtInfo	struct	Detailed debt information (DebtFullInfo above)
maxCollateralToLiquidate	uint256	Maximum collateral that can be liquidated
maxDebtToLiquidate	uint256	Maximum debt that can be liquidated
liquidationProtocolFee	uint256	Protocol fee applied on the liquidation bonus
amountToPassToLiquidationCall	uint256	Adjusted debt amount for the liquidation call

getLiquidationInfo (with custom debt liquidation amount)

getLiquidationInfo(address user, address collateralAsset, address debtAsset, uint256 debtLiquidationAmount) public view override returns (LiquidationInfo memory)

Returns comprehensive liquidation parameters for a user given a specific collateral asset and debt asset, considering a custom maximum debt liquidation amount. The function aggregates the user’s position, collateral and debt details, checks if liquidation conditions are met, and computes the optimal amounts for liquidation—including any applicable protocol fees.

Input Parameters:

Name	Type	Description
user	address	The address of the user
collateralAsset	address	The address of the collateral asset to be liquidated
debtAsset	address	The address of the debt asset to be repaid
debtLiquidationAmount	uint256	The maximum debt amount that can be liquidated (if lower than the user’s debt balance)

Return Values:

Name	Type	Description
LiquidationInfo	struct	Detailed liquidation information for the specified user and assets

The LiquidationInfo struct is composed of the following fields:

Name	Type	Description
userInfo	struct	Aggregated position details of the user (UserPositionFullInfo above)
collateralInfo	struct	Detailed collateral information (CollateralFullInfo above)
debtInfo	struct	Detailed debt information (DebtFullInfo above)
maxCollateralToLiquidate	uint256	Maximum collateral that can be liquidated
maxDebtToLiquidate	uint256	Maximum debt that can be liquidated
liquidationProtocolFee	uint256	Protocol fee applied on the liquidation bonus
amountToPassToLiquidationCall	uint256	Adjusted debt amount for the liquidation call