Swap Features

The Aave Labs interface integrates multiple features integrating token swaps detailed below.

Swap Tokens

The Swap Tokens feature enables users to swap between tokens using ParaSwap or CoW Swapas the swap provider, depending on network availability. Tokens traded using CoW Swap will incur a fee depending on token pair. A discounted fee of 15bps is applied to swaps between correlated assets (e.g. ETH/wstETH), for all other swaps a fee of 25bps is applied — the list of correlated assets is reviewed and updated periodically:

• Stablecoin asset group: USDC, USDT, DAI, GHO, EURC, USDbC, USDe, USDS, sUSDe, RLUSD, PYUSD, LUSD, sDAI, crvUSD, USD₮0, USDC.e, EURe, xDAI, wxDAI

• ETH correlated asset group: weETH, ETH, WETH, wstETH, cbETH, ezETH, wrsETH, osETH, rETH, ETHx

• BTC correlated asset group: cbBTC, WBTC, LBTC, tBTC, eBTC

Swap Adapter Contracts

The swap adapter contracts integrate Aave's Flash Loans and the ParaSwap DEX aggregator to facilitate advanced actions such as repaying borrow positions using collateral, swapping collateral assets, swapping borrow positions, and withdrawing and swapping assets. They allow users to perform complex operations in a single transaction, leveraging the liquidity of the Aave protocol and the atomic swapping capabilities of decentralized exchanges.

The table below outlines swap feature availability across V3 markets on the Aave Labs interface:

Market	Token Swap	Repay With Collateral	Collateral Swap	Debt Swap	Withdraw & Swap
Ethereum Core
Ethereum Prime
Ethereum EtherFi
Arbitrum
Avalanche
Base
BNB
Optimism
Polygon
Gnosis
Metis
Scroll
ZKsync
Sonic
Celo
Soneium

Repay With Collateral

The ParaSwapRepayAdapter contract enables users to repay their borrow positions on Aave using their supplied collateral directly, without the need to unwind their positions or provide additional liquidity. It leverages Aave's Flash Loans and the ParaSwap DEX aggregator to swap the user's collateral for the borrowed asset and repay the borrow position in a single atomic transaction.

By using this adapter, users can efficiently manage their positions and reduce their borrow positions using their existing collateral, saving on transaction costs and avoiding manual steps.

The source code is available on GitHub.

Reference Integration: useCollateralRepaySwap.tsx

Write Methods

executeOperation

function executeOperation(    address asset,    uint256 amount,    uint256 premium,    address initiator,    bytes calldata params) external override nonReentrant returns (bool)

Uses the received funds from the flash loan to repay a borrow position on the protocol on behalf of the user. Then, pulls the collateral from the user and swaps it to the debt asset to repay the flash loan.

The user should give this contract allowance to pull the aTokens in order to withdraw the underlying asset, swap it, and repay the flash loan.

Supports only one asset on the flash loan.

The params parameter should be the ABI-encoded values of the following:

• IERC20Detailed debtAsset — The address of the borrow position asset

• uint256 debtRepayAmount — The amount of the borrow position to be repaid

• uint256 buyAllBalanceOffset — Offset in the ParaSwap calldata if swapping all balance

• uint256 rateMode — The rate mode of the borrow position to be repaid

• bytes paraswapData — Data for the ParaSwap Adapter

• PermitSignature permitSignature — Struct containing the permit signature, set to zeroes if not used

Input Parameters:

Name	Type	Description
asset	address	The address of the flash-borrowed asset
amount	uint256	The amount of the flash-borrowed asset
premium	uint256	The fee of the flash-borrowed asset
initiator	address	The address of the flash loan initiator
params	bytes	The byte-encoded parameters passed when initiating the flash loan

Return Values:

Type	Description
bool	True if the execution of the operation succeeds, false otherwise

swapAndRepay

function swapAndRepay(    IERC20Detailed collateralAsset,    IERC20Detailed debtAsset,    uint256 collateralAmount,    uint256 debtRepayAmount,    uint256 debtRateMode,    uint256 buyAllBalanceOffset,    bytes calldata paraswapData,    PermitSignature calldata permitSignature) external nonReentrant

Swaps the user's collateral for the debt asset and then repays the borrow position on the protocol on behalf of the user without using flash loans. This method can be used when the temporary transfer of the collateral asset to this contract does not affect the user's position.

The user should give this contract allowance to pull the aTokens in order to withdraw the underlying asset.

Input Parameters:

Name	Type	Description
collateralAsset	IERC20Detailed	The address of the collateral asset to be swapped
debtAsset	IERC20Detailed	The address of the debt asset
collateralAmount	uint256	The maximum amount of the collateral to be swapped
debtRepayAmount	uint256	The amount of the borrow position to be repaid, or maximum amount when repaying all
debtRateMode	uint256	The rate mode of the borrow position to be repaid
buyAllBalanceOffset	uint256	Offset in the ParaSwap calldata if swapping all balance, otherwise 0
paraswapData	bytes	Data for the ParaSwap Adapter
permitSignature	PermitSignature	Struct containing the permit signature, set to zeroes if not used

PermitSignature Struct

struct PermitSignature {    uint256 deadline;    uint8 v;    bytes32 r;    bytes32 s;}

Members:

Name	Type	Description
deadline	uint256	The deadline timestamp for the permit signature
v	uint8	The V parameter of the ECDSA signature
r	bytes32	The R parameter of the ECDSA signature
s	bytes32	The S parameter of the ECDSA signature

---

Collateral Swap

The ParaSwapLiquiditySwapAdapter contract allows users to swap their supplied collateral from one asset to another in a single transaction using Aave's Flash Loans and the ParaSwap DEX aggregator.

This adapter enables users to rebalance their collateral positions without needing to withdraw and re-supply assets manually. By leveraging flash loans, the user can swap their existing collateral to a new asset and supply it back into the Aave protocol in a single transaction.

The source code is available on GitHub.

Reference Integration: useCollateralSwap.tsx

Write Methods

executeOperation

function executeOperation(    address asset,    uint256 amount,    uint256 premium,    address initiator,    bytes calldata params) external override nonReentrant returns (bool)

Swaps the received amount from the flash loan into the specified asset. The received funds from the swap are then supplied into the protocol on behalf of the user.

The user should give this contract allowance to pull the aTokens in order to withdraw the underlying asset and repay the flash loan.

The params parameter should be the ABI-encoded values of the following:

• IERC20Detailed assetToSwapTo — The address of the underlying asset to be swapped to and supplied

• uint256 minAmountToReceive — The minimum amount to be received from the swap

• uint256 swapAllBalanceOffset — Offset in the Augustus calldata if swapping all balance, otherwise 0

• bytes swapCalldata — Calldata for ParaSwap's Augustus Swapper contract

• IParaSwapAugustus augustus — Address of ParaSwap's Augustus Swapper contract

• PermitSignature permitParams — Struct containing the permit signature, set to zeroes if not used

Input Parameters:

Name	Type	Description
asset	address	The address of the flash-borrowed asset
amount	uint256	The amount of the flash-borrowed asset
premium	uint256	The fee of the flash-borrowed asset
initiator	address	The address of the flash loan initiator
params	bytes	The byte-encoded parameters passed when initiating the flash loan

Return Values:

Type	Description
bool	True if the execution of the operation succeeds, false otherwise

swapAndDeposit

function swapAndDeposit(    IERC20Detailed assetToSwapFrom,    IERC20Detailed assetToSwapTo,    uint256 amountToSwap,    uint256 minAmountToReceive,    uint256 swapAllBalanceOffset,    bytes calldata swapCalldata,    IParaSwapAugustus augustus,    PermitSignature calldata permitParams) external nonReentrant

Swaps an amount of an asset to another and supplies the new asset amount on behalf of the user without using a flash loan. This method can be used when the temporary transfer of the collateral asset to this contract does not affect the user's position.

The user should give this contract allowance to pull the aTokens in order to withdraw the underlying asset and perform the swap.

Input Parameters:

Name	Type	Description
assetToSwapFrom	IERC20Detailed	The address of the underlying asset to be swapped from
assetToSwapTo	IERC20Detailed	The address of the underlying asset to be swapped to and supplied
amountToSwap	uint256	Amount to be swapped, or maximum amount when swapping all balance
minAmountToReceive	uint256	Minimum amount to be received from the swap
swapAllBalanceOffset	uint256	Offset in Augustus calldata if swapping all balance, otherwise 0
swapCalldata	bytes	Calldata for ParaSwap's Augustus Swapper contract
augustus	IParaSwapAugustus	Address of ParaSwap's Augustus Swapper contract
permitParams	PermitSignature	Struct containing the permit signature, set to zeroes if not used

---

Borrow Position Swap

The ParaSwapDebtSwapAdapter contracts allow users to swap their borrow positions from one asset to another. They leverage Aave's Flash Loans and the ParaSwap DEX aggregator to perform the swap in a single atomic transaction.

There are two versions of the adapter:

• ParaSwapDebtSwapAdapterV3: The standard version that supports swapping any borrow position asset.

  • Source Code: GitHub

  • Reference Integration: useDebtSwitch.tsx

• ParaSwapDebtSwapAdapterV3GHO: A specialized version that supports GHO, where GHO can be flash minted via the ERC-3156 interface.

  • Source Code: GitHub

  • Reference Integration: useDebtSwitch.tsx

ParaSwapDebtSwapAdapterV3

The ParaSwapDebtSwapAdapterV3 contract allows users to swap their borrow positions from one asset to another, enabling borrow position refinancing on the Aave protocol.

This adapter leverages Aave's Flash Loans and the ParaSwap DEX aggregator to perform the borrow position swap in a single transaction.

Write Methods

executeOperation

function executeOperation(    address[] calldata assets,    uint256[] calldata amounts,    uint256[] calldata,    address initiator,    bytes calldata params) external returns (bool)

Performs the borrow position swap operation using the received funds from the flash loan.

Performs the swap and repay operation using the borrowed funds from the flash loan, and then re-borrows the new borrow position asset to maintain the overall borrow position.

The params parameter should be the ABI-encoded values required for the operation, such as:

• The addresses of the borrow position assets involved

• The rate modes of the borrow positions

• ParaSwap swap data

• Any necessary permit signatures

Input Parameters:

Name	Type	Description
assets	address[]	The addresses of the assets being borrowed in the flash loan
amounts	uint256[]	The amounts of the assets being borrowed
premiums	uint256[]	The fees for the flash loans
initiator	address	The address of the flash loan initiator
params	bytes	Arbitrary data containing the parameters needed for the operation

Return Values:

Type	Description
bool	True if the execution of the operation succeeds, false otherwise

ParaSwapDebtSwapAdapterV3GHO

The ParaSwapDebtSwapAdapterV3GHO contract is a specialized version of the borrow position swap adapter that supports GHO, allowing users to swap their borrow positions involving GHO. It utilizes the ERC-3156 flash mint interface for GHO.

Performs the swap and repay operation using the borrowed funds from the flash loan, and then re-borrows the borrow position asset to maintain the overall borrow position.

Write Methods

onFlashLoan

function onFlashLoan(    address initiator,    address token,    uint256 amount,    uint256 fee,    bytes calldata data) external override returns (bytes32)

This is the ERC-3156 Flash Loan callback function that gets called when the contract receives a flash loan (in this case, flash mint) from the GHO Flash Minter.

Input Parameters:

Name	Type	Description
initiator	address	The initiator of the flash loan
token	address	The address of the token being borrowed
amount	uint256	The amount of tokens being borrowed
fee	uint256	The fee for the flash loan
data	bytes	Arbitrary data containing the parameters needed for the operation

Return Values:

Type	Description
bytes32	The keccak256 hash of the string 'ERC3156FlashBorrower.onFlashLoan'

---

Withdraw & Swap

The ParaSwapWithdrawSwapAdapter contract allows users to withdraw their supplied assets from Aave and swap them to another asset in a single transaction using the ParaSwap DEX aggregator.

This adapter enables users to efficiently exit positions and swap their assets without having to perform multiple transactions, reducing gas costs and simplifying the user experience.

The source code is available on GitHub.

Reference Integration: WithdrawAndSwitchActions.tsx

Write Methods

withdrawAndSwap

function withdrawAndSwap(    IERC20Detailed assetToSwapFrom,    IERC20Detailed assetToSwapTo,    uint256 amountToSwap,    uint256 minAmountToReceive,    uint256 swapAllBalanceOffset,    bytes calldata swapCalldata,    IParaSwapAugustus augustus,    PermitSignature calldata permitParams) external nonReentrant

Swaps an amount of an asset to another after a withdrawal and transfers the new asset to the user. The user should give this contract allowance to pull the aTokens in order to withdraw the underlying asset and perform the swap.

Input Parameters:

Name	Type	Description
assetToSwapFrom	IERC20Detailed	The address of the underlying asset to be swapped from
assetToSwapTo	IERC20Detailed	The address of the underlying asset to be swapped to
amountToSwap	uint256	Amount to be swapped, or maximum amount when swapping all balance
minAmountToReceive	uint256	Minimum amount to be received from the swap
swapAllBalanceOffset	uint256	Offset in Augustus calldata if swapping all balance, otherwise 0
swapCalldata	bytes	Calldata for ParaSwap's Augustus Swapper contract
augustus	IParaSwapAugustus	Address of ParaSwap's Augustus Swapper contract
permitParams	PermitSignature	Struct containing the permit signature, set to zeroes if not used

executeOperation

Note that in this contract, the executeOperation method is overridden but simply reverts with NOT_SUPPORTED, so it's not intended to be used.