↪ pool

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Pool

This contract serves as the primary interface for users. Most interactions with the Hyperlend Protocol occur via the Pool contract.

Users can:

• Supply assets

• Withdraw assets

• Borrow funds

• Repay loans

• Enable or disable supplied assets as collateral

• Liquidate positions

• Execute flash loans

The source code is available on GitHub.

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Write Methods

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supply

function supply(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode
) public virtual override

Deposits a specified amount of an asset into the protocol, minting equivalent hTokens and transferring them to the onBehalfOf address.

Before supplying, the Pool contract must have the necessary allowance to spend funds on behalf of msg.sender for at least the specified amount of the asset.

The referral program is currently inactive; you can pass 0 as referralCode. This feature may be activated in the future.

Parameters:

Name	Type	Description
asset	address	The address of the underlying asset being supplied to the pool
amount	uint256	The amount of the asset to supply
onBehalfOf	address	The address that will receive the corresponding hTokens. This is the only address that can withdraw the asset from the pool.
referralCode	uint16	The referral program is currently inactive; you can pass 0.

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supplyWithPermit

function supplyWithPermit(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode,
    uint256 deadline,
    uint8 permitV,
    bytes32 permitR,
    bytes32 permitS
) public virtual override

Allows supplying an asset using a permit signature for transfer approval, eliminating the need for a separate approval transaction before supplying the asset to the pool. See: EIP-2612.

The permit signature must be signed by msg.sender with the spender set to the Pool address.

The referral program is currently inactive; you can pass 0 as referralCode. This feature may be activated in the future through a Hyperlend governance proposal.

Parameters:

Name	Type	Description
asset	address	The address of the underlying asset being supplied. The same asset used in the permit signature (v, r, s)
amount	uint256	The amount of the asset to supply and approve via permit. The same amount used in the permit signature (v, r, s)
onBehalfOf	address	The address that will receive the hTokens.
referralCode	uint16	The referral program is currently inactive; you can pass 0.
deadline	uint256	The UNIX timestamp until which the permit signature is valid
permitV	uint8	The v parameter of the ERC712 permit signature
permitR	bytes32	The r parameter of the ERC712 permit signature
permitS	bytes32	The s parameter of the ERC712 permit signature

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withdraw

function withdraw(address asset, uint256 amount, address to) public virtual override returns (uint256)

Withdraws a specified amount of the underlying asset from the reserve, burning the equivalent hTokens owned. For example, if a user has 100 hUSDC and calls withdraw(), they will receive 100 USDC, and the 100 hUSDC will be burned.

If the user has any existing debt backed by the underlying token, the maximum amount available to withdraw is limited to ensure the user's health factor remains above 1 after the withdrawal.

When withdrawing to another address, msg.sender must possess the hTokens that will be burned by the Pool.

Parameters:

Name	Type	Description
asset	address	The address of the underlying asset to withdraw, not the hToken
amount	uint256	The amount of the underlying asset to withdraw, expressed in wei units. Use type(uint256).max to withdraw the entire hToken balance
to	address	The address that will receive the underlying asset. This will be the same as msg.sender if the user wants to receive the tokens themselves, or another address if the beneficiary is different

Returns:

Type	Description
uint256	The final amount withdrawn

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borrow

function borrow(
    address asset,
    uint256 amount,
    uint256 interestRateMode,
    uint16 referralCode,
    address onBehalfOf
) public virtual override

Allows users to borrow a specific amount of the reserve's underlying asset, provided the borrower has supplied enough collateral or has been granted sufficient allowance by a credit delegator on the corresponding debt token (VariableDebtToken). For example, if a user borrows 100 USDC and passes their own address as onBehalfOf, they will receive 100 USDC and 100 variable debt tokens.

Note: If onBehalfOf is not the same as msg.sender, then onBehalfOf must have supplied enough collateral via supply() and have delegated credit to msg.sender via approveDelegation() on the VariableDebtToken contract.

The referral program is currently inactive; you can pass 0 as referralCode.

Parameters:

Name	Type	Description
asset	address	The address of the underlying asset to borrow
amount	uint256	The amount to borrow, expressed in wei units
interestRateMode	uint256	Should always be passed a value of 2 (variable rate mode)
referralCode	uint16	The referral program is currently inactive; you can pass 0.
onBehalfOf	address	The address of the borrower. If they want to borrow against their own collateral, this should be their own address, or the address of the credit delegator if the caller has been granted credit delegation allowance

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repay

function repay(
    address asset,
    uint256 amount,
    uint256 interestRateMode,
    address onBehalfOf
) public virtual override returns (uint256)

Repays a borrowed amount on a specific reserve, burning the equivalent debt tokens owned. For example, if a user repays 100 USDC, the 100 variable debt tokens owned by the onBehalfOf address will be burned.

When repaying, the Pool contract must have allowance to spend funds on behalf of msg.sender for at least the amount for the asset being repaid. This can be done via the standard ERC20 approve() method on the underlying token contract.

You cannot call repay() multiple times in the same block.

Parameters:

Name	Type	Description
asset	address	The address of the borrowed underlying asset
amount	uint256	The amount to repay, expressed in wei units. Use type(uint256).max to repay the whole debt, only when the repayment is not executed on behalf of a third party. When repaying on behalf of another user, it's recommended to send an amount slightly higher than the current borrowed amount
interestRateMode	uint256	Only available option is 2 (variable rate mode)
onBehalfOf	address	The address of the user whose debt will be reduced or removed. This should be the address of the user calling the function if they want to reduce or remove their own debt, or the address of another borrower whose debt should be removed

Returns:

Type	Description
uint256	The final amount repaid

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repayWithPermit

function repayWithPermit(
    address asset,
    uint256 amount,
    uint256 interestRateMode,
    address onBehalfOf,
    uint256 deadline,
    uint8 permitV,
    bytes32 permitR,
    bytes32 permitS
) public virtual override returns (uint256)

Allows repaying a borrowed amount using a permit signature for transfer approval, removing the need for a separate approval transaction before repaying the asset to the pool. See: EIP-2612.

The permit signature must be signed by msg.sender with the spender set to the Pool address.

Parameters:

Name	Type	Description
asset	address	The address of the borrowed underlying asset. The same asset used in the permit signature (v, r, s)
amount	uint256	The amount to repay, expressed in wei units. Use type(uint256).max to repay the whole debt without leaving hToken dust. The same amount used in the permit signature (v, r, s)
interestRateMode	uint256	Only available option is 2 (variable rate mode)
onBehalfOf	address	The address of the user whose debt will be reduced or removed. This should be the address of the user calling the function if they want to reduce or remove their own debt, or the address of another borrower whose debt should be removed
deadline	uint256	The UNIX timestamp until which the permit signature is valid
permitV	uint8	The v parameter of the ERC712 permit signature
permitR	bytes32	The r parameter of the ERC712 permit signature
permitS	bytes32	The s parameter of the ERC712 permit signature

Returns:

Type	Description
uint256	The final amount repaid

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repayWithATokens

function repayWithATokens(
    address asset,
    uint256 amount,
    uint256 interestRateMode
) public virtual override returns (uint256)

Allows a user to repay a borrowed amount on a specific reserve using the reserve's hTokens, burning the equivalent debt tokens. For example, a user repays 100 USDC using 100 hUSDC, burning 100 variable debt tokens. Passing type(uint256).max as the amount will clean up any residual hToken dust balance if the user's hToken balance is insufficient to cover the whole debt.

Parameters:

Name	Type	Description
asset	address	The address of the borrowed underlying asset
amount	uint256	The amount to repay. Use type(uint256).max to repay the whole debt for asset without leaving aToken dust
interestRateMode	uint256	Only available option is 2 (variable rate mode)

Returns:

Type	Description
uint256	The final amount repaid

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setUserUseReserveAsCollateral

function setUserUseReserveAsCollateral(address asset, bool useAsCollateral) public virtual override

Allows suppliers to enable or disable a specific supplied asset as collateral. Sets the asset of msg.sender to be used as collateral or not.

An asset in Isolation Mode can be enabled as collateral only if no other asset is already enabled as collateral.

The user cannot disable an asset as collateral if they have an outstanding debt position that would cause their health factor to drop below 1 upon disabling the given asset as collateral.

Parameters:

Name	Type	Description
asset	address	The address of the underlying asset supplied
useAsCollateral	bool	true if the user wants to use the supply as collateral, false otherwise

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liquidationCall

function liquidationCall(
    address collateralAsset,
    address debtAsset,
    address user,
    uint256 debtToCover,
    bool receiveAToken
) public virtual override

Allows liquidators to liquidate a non-healthy position (with a health factor below 1).

When a user's health factor is below 1, the liquidator repays the debtToCover amount of the user's debt. This amount is a portion or the entirety of the outstanding borrowed amount on behalf of the borrower. The liquidator then receives a proportional amount of the collateralAsset (discounted collateral) plus a liquidation bonus to compensate for market risk.

Liquidators can choose to receive an equivalent amount of collateral hTokens instead of the underlying asset. When the liquidation is successfully completed, the health factor of the position increases, bringing it above 1.

Liquidators can only close a certain portion of the collateral defined by the close factor. Currently, the close factor is 0.5, meaning liquidators can only liquidate up to 50% of the amount pending to be repaid in a position. The liquidation discount applies to this amount.

In most cases, profitable liquidators will choose to liquidate as much as allowed (50% of the user's position).

The debtToCover parameter can be set to type(uint256).max, and the protocol will proceed with the maximum liquidation allowed by the close factor.

To check a user's health factor, use getUserAccountData().

Liquidators must approve() the Pool contract to use debtToCover of the underlying ERC20 asset used for the liquidation.

Parameters:

Name	Type	Description
collateralAsset	address	The address of the underlying asset used as collateral, to receive as a result of the liquidation
debtAsset	address	The address of the underlying borrowed asset to be repaid during the liquidation
user	address	The address of the borrower being liquidated
debtToCover	uint256	The debt amount of the borrowed asset that the liquidator will repay
receiveAToken	bool	true if the liquidator wants to receive the aTokens equivalent of the purchased collateral, false to receive the underlying collateral asset directly

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flashLoan

function flashLoan(
    address receiverAddress,
    address[] calldata assets,
    uint256[] calldata amounts,
    uint256[] calldata interestRateModes,
    address onBehalfOf,
    bytes calldata params,
    uint16 referralCode
) public virtual override

Allows users to access the pool's liquidity for a given list of assets within a single transaction, as long as the amount borrowed plus a fee is returned. The receiver must approve the Pool contract for at least the amount borrowed plus the fee; otherwise, the transaction will revert.

The flash loan fee is waived for approved FLASH_BORROWER.

There are security considerations for developers of flash loan receiver contracts that must be taken into account. For further details, visit the Flash Loan Developers Guide.

The referral program is currently inactive; you can pass 0 as referralCode. This feature may be activated in the future through a Hyperlend governance proposal.

Parameters:

Name	Type	Description
receiverAddress	address	The address of the contract receiving the flash-borrowed funds, implementing the IFlashLoanReceiver interface
assets	address[]	The addresses of the assets being flash-borrowed
amounts	uint256[]	The amounts of the assets being flash-borrowed. This array must contain the same number of entries as assets
interestRateModes	uint256[]	The types of the debt position to open if the flash loan is not returned: 0 -> Don't open any debt; the amount plus fee must be paid in this case, or the transaction will revert if the funds can't be transferred from the receiver. 2 -> Open a variable rate borrow position for the value of the amount flash-borrowed to the onBehalfOf address
onBehalfOf	address	The address that will receive the debt if the associated interestRateModes is 1 or 2. onBehalfOf must already have approved sufficient borrow allowance of the associated asset to msg.sender
params	bytes	Variadic packed parameters to pass to the receiver as extra information
referralCode	uint16	The referral program is currently inactive; you can pass 0. This code is used to register the integrator initiating the operation for potential rewards. Use 0 if executed directly by the user without intermediaries

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