Aave V3 L2 Pool Contract

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 and setUserEMode, work the same as on other networks. See Pool.

Encoded arguments use the 16-bit asset id (the reserve index in getReservesList()) instead of the 160-bit asset address.

The source code is available on GitHub.

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

Methods

supply

Solidity

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.

Build the input with encodeSupplyParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the supply function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time
144-159	`uint16`	referralCode	Used for 3rd party integrations

supplyWithPermit

Solidity

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.

Build the input with encodeSupplyWithPermitParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the supply function packed in one bytes32. See the `args` bit layout below
r	`bytes32`	The R parameter of EIP-712 permit signature
s	`bytes32`	The S parameter of EIP-712 permit signature

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time
144-159	`uint16`	referralCode	Used for 3rd party integrations
160-191	`uint32`	shortenedDeadline	Shortened deadline from the original `uint256`
192-199	`uint8`	permitV	The V parameter of EIP-712 permit signature

withdraw

Solidity

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.

Build the input with encodeWithdrawParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the withdraw function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
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 Values:

Name	Type	Description
amount	`uint256`	The 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

Solidity

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, and msg.sender incurs the debt.

Build the input with encodeBorrowParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the borrow function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time
144-151	`uint8`	shortenedInterestRateMode	Must be 2 (variable)
152-167	`uint16`	referralCode	Used for 3rd party integrations

repay

Solidity

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.

Build the input with encodeRepayParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the repay function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time, if `type(uint128).max` the value will be expanded to `type(uint256).max`
144-151	`uint8`	shortenedInterestRateMode	Must be 2 (variable)

Return Values:

Type	Description
`uint256`	The final amount repaid

repayWithPermit

Solidity

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.

Build the input with encodeRepayWithPermitParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the repayWithPermit function packed in one bytes32. See the `args` bit layout below
r	`bytes32`	The R parameter of EIP-712 permit signature
s	`bytes32`	The S parameter of EIP-712 permit signature

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time, if `type(uint128).max` the value will be expanded to `type(uint256).max`
144-151	`uint8`	shortenedInterestRateMode	Must be 2 (variable)
152-183	`uint32`	shortenedDeadline	Shortened deadline from original `uint256`
184-191	`uint8`	permitV	The V parameter of EIP-712 permit signature

Return Values:

Type	Description
`uint256`	The final amount repaid

repayWithATokens

Solidity

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.

Build the input with encodeRepayWithATokensParams() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the repayWithATokens function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16-143	`uint128`	shortenedAmount	Cast to 256 bits at decode time, if `type(uint128).max` the value will be expanded to `type(uint256).max`
144-151	`uint8`	shortenedInterestRateMode	Must be 2 (variable)

Return Values:

Type	Description
`uint256`	The final amount repaid

setUserUseReserveAsCollateral

Solidity

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.

Build the input with encodeSetUserUseReserveAsCollateral() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args	`bytes32`	Arguments for the setUserUseReserveAsCollateral function packed in one bytes32. See the `args` bit layout below

The args bit layout:

Bits	Type	Field	Description
0-15	`uint16`	assetId	The index of the asset in the reservesList
16	`bool`	useAsCollateral	1 to enable the reserve as collateral, 0 to disable it

liquidationCall

Solidity

function liquidationCall(bytes32 args1, bytes32 args2) external override

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

Build the input with encodeLiquidationCall() in the L2Encoder helper contract.

Input Parameters:

Name	Type	Description
args1	`bytes32`	Part of the arguments for the liquidationCall function packed in one bytes32. See the `args1` bit layout below
args2	`bytes32`	Part of the arguments for the liquidationCall function packed in one bytes32. See the `args2` bit layout below

The args1 bit layout:

Bits	Type	Field	Description
0-15	`uint16`	collateralAssetId	The index of the collateral asset in the reservesList
16-31	`uint16`	debtAssetId	The index of the debt asset in the reservesList
32-191	`address`	user	The address of the user being liquidated

The args2 bit layout:

Bits	Type	Field	Description
0-127	`uint128`	shortenedDebtToCover	Cast to 256 bits at decode time , if `type(uint128).max` the value will be expanded to `type(uint256).max`
128	`bool`	receiveAToken	1 to receive aTokens, 0 to receive the underlying asset