L2Pool

The main transaction cost on L2 comes from calldata. To minimize this cost, Aave V3 uses a different contract on L2 networks that allows calldata of Pool methods to be compressed.

L2Pool is the contract for the L2 optimized user facing methods of the protocol that takes byte encoded input arguments. It exposes the liquidity management methods that can be invoked using either Solidity or Web3 libraries. The L2Pool contract is a calldata optimized extension of the Pool contract allowing users to pass compact calldata representation to reduce transaction costs on L2 rollups.

Pool methods not exposed in L2Pool.sol (such as flashLoan, setUserEMode etc.) are the same on L2 as on other versions of protocol. Refer to Pool docs for the rest of the methods.

Since there are a limited set of supported assets that are already given an individual id, we use the 16 bit asset id in the encoded arguments instead of 160 bit asset address.

The source code is available on GitHub.

Threre is an additional L2Encoder helper contract with view methods to encode transaction params for compressed methods.

Methods

supply

function supply(bytes32 args) external override

Calldata efficient wrapper of the supply function on behalf of the caller. Supplies asset into the protocol, minting the same amount of corresponding aTokens, and transferring them to msg.sender.

You can use data returned from encodeSupplyParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the supply function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144-159: uint16 referralCode - used for 3rd party integrations

supplyWithPermit

function supplyWithPermit(bytes32 args, bytes32 r, bytes32 s) external override

Calldata efficient wrapper of the supplyWithPermit function on behalf of the caller. Supply with transfer approval of supplied asset via permit function. This method removes the need for separate approval transaction before supplying asset to the pool.

You can use data returned from encodeSupplyWithPermitParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the supply function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144-159: uint16 referralCode - used for 3rd party integrations
bit 160-191: uint32 shortenedDeadline - shortened deadline from the original uint256
bit 192-199: uint8 permitV - the V parameter of ERC712 permit signature

rbytes32The R parameter of ERC712 permit signature
sbytes32The S parameter of ERC712 permit signature

withdraw

function withdraw(bytes32 args) external override returns (uint256)

Calldata efficient wrapper of the withdraw function, withdrawing to the caller. Withdraws amount of the underlying asset, i.e. redeems the underlying token and burns the aTokens.

If the user has any existing debt backed by the underlying token, the maximum amount available to withdraw is the amount that will not leave the user with a health factor < 1 after the withdrawal.

You can use data returned from encodeWithdrawParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the withdraw function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max

Return Value:

NameTypeDescription
amountuint256The final amount of the underlying asset withdrawn, denominated in the base unit of the asset (e.g., wei for ETH, smallest unit for ERC-20 tokens). This is the amount actually transferred to the caller, accounting for constraints like liquidity and health factor.

borrow

function borrow(bytes32 args) external override

Calldata efficient wrapper of the borrow function, borrowing on behalf of the caller. Borrows amount of asset with interestRateMode, sending the amount to msg.sender, with the debt being incurred by onBehalfOf.

You can use data returned from encodeBorrowParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the borrow function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144 - 151: uint8 shortenedInterestRateMode
bit 152 - 167: uint16 referralCode - used for 3rd party integrations

repay

function repay(bytes32 args) external override returns (uint256)

Calldata efficient wrapper of the repay function, repaying on behalf of the caller. Repays debt of an asset for the given interestRateMode.

You can use data returned from encodeRepayParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the repay function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144 - 151: uint8 shortenedInterestRateMode

Return Values:

TypeDescription
uint256The final amount repaid

repayWithPermit

function repayWithPermit(bytes32 args, bytes32 r, bytes32 s) external override returns (uint256)

Calldata efficient wrapper of the repayWithPermit function, repaying on behalf of the caller. Repay with transfer approval of borrowed asset via permit function. This method removes the need for separate approval transaction before repaying asset to the pool.

You can use data returned from encodeRepayWithPermitParams() method in L2Encoder helper contract to pass to this method.​

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the repayWithPermit function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144 - 151: uint8 shortenedInterestRateMode
bit 152-183: uint32 shortenedDeadline - shortened deadline from original uint256
bit 184-191: uint8 permitV - the V parameter of ERC712 permit signature

rbytes32The R parameter of ERC712 permit signature
sbytes32The S parameter of ERC712 permit signature

Return Values:

TypeDescription
uint256The final amount repaid

repayWithATokens

function repayWithATokens(bytes32 args) external override returns (uint256)

Calldata efficient wrapper of the repayWithATokens function. Allows user to repay with aTokens of the underlying debt asset without any approvals, for example, Pay DAI debt using aDAI tokens.

You can use data data returned from encodeRepayWithATokensParams() method in L2Encoder helper contract to pass to this method.

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the repayWithATokens function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16-143: uint128 shortenedAmount - cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 144 - 151: uint8 shortenedInterestRateMode

Return Values:

TypeDescription
uint256The final amount repaid

setUserUseReserveAsCollateral

function setUserUseReserveAsCollateral(bytes32 args) external override

Calldata efficient wrapper of the setUserUseReserveAsCollateral function. Sets the asset of msg.sender to be used as collateral or not.

You can use data returned from encodeSetUserUseReserveAsCollateral() method in L2Encoder helper contract to pass to this method.​

Input Parameters:

NameTypeDescription
argsbytes32

Arguments for the setUserUseReserveAsCollateral function packed in one bytes32
bit 0-15: uint16 assetId - the index of the asset in the reservesList
bit 16: 0 => enable useAsCollateral, 1 => disable useAsCollateral

liquidationCall

function liquidationCall(bytes32 args1, bytes32 args2) external override

Calldata efficient wrapper of the liquidationCall function. Liquidate positions with a health factor below 1.

You can use data returned from encodeLiquidationCall() method in L2Encoder helper contract to pass to this method.​

Input Parameters:

NameTypeDescription
args1bytes32

Part of the arguments for the liquidationCall function packed in one bytes32
bit 0-15: uint16 collateralAssetId - the index of the collateral asset in the reservesList
bit 16-31: uint16 debtAssetId - the index of the debt asset in the reservesList
bit 32-191: address of the user being liquidated

args2bytes32

Part of the arguments for the liquidationCall function packed in one bytes32
bit 0-127: uint128 shortenedDebtToCover is cast to 256 bits at decode time, if type(uint128).max the value will be expanded to type(uint256).max
bit 128: receiveAToken - 0 => receive aToken, 1 => receive underlying asset

Aave.com provides information and resources about the fundamentals of the decentralised non-custodial liquidity protocol called the Aave Protocol, comprised of open-source self-executing smart contracts that are deployed on various permissionless public blockchains, such as Ethereum (the "Aave Protocol" or the "Protocol"). Aave Labs does not control or operate any version of the Aave Protocol on any blockchain network.