AToken Contract Interface

aTokens are tokens minted and burnt upon supply and withdraw of assets to Bend, which denote the amount of crypto assets supplied and the yield earned on those assets. aTokens’ value is pegged to the value of the corresponding supplied asset at a 1:1 ratio and can be safely stored, transferred or traded. All yield collected by the aTokens' reserves are distributed to aToken holders directly by continuously increasing their wallet balance (i.e. rebasing).

All standard EIP20 methods are implemented for aTokens, such as balanceOf, transfer, transferFrom, approve, totalSupply etc.

mint

function mint(address caller, address onBehalfOf, uint256 amount, uint256 index) external virtual returns (bool)

Mints amount aTokens to user

Parameters

Name	Type	Description
caller	address	The address performing the mint
onBehalfOf	address	The address of the user that will receive the minted aTokens
amount	uint256	The amount of tokens getting minted
index	uint256	The next liquidity index of the reserve

Return Values

Name	Type	Description
[0]	bool	true if the previous balance of the user was 0

burn

function burn(address from, address receiverOfUnderlying, uint256 amount, uint256 index) external virtual

Burns aTokens from user and sends the equivalent amount of underlying to receiverOfUnderlying

In some instances, the mint event could be emitted from a burn transaction if the amount to burn is less than the interest that the user accrued

Parameters

Name	Type	Description
from	address	The address from which the aTokens will be burned
receiverOfUnderlying	address	The address that will receive the underlying
amount	uint256	The amount being burned
index	uint256	The next liquidity index of the reserve

mintToPOLFeeCollector

function mintToPOLFeeCollector(uint256 amount, uint256 index) external virtual

Mints aTokens to the reserve POL fee collector

Parameters

Name	Type	Description
amount	uint256	The amount of tokens getting minted
index	uint256	The next liquidity index of the reserve

transferOnLiquidation

function transferOnLiquidation(address from, address to, uint256 value) external virtual

Transfers aTokens in the event of a borrow being liquidated, in case the liquidators reclaims the aToken

Parameters

Name	Type	Description
from	address	The address getting liquidated, current owner of the aTokens
to	address	The recipient
value	uint256	The amount of tokens getting transferred

balanceOf

function balanceOf(address user) public view virtual returns (uint256)

Returns the amount of tokens owned by account.

totalSupply

function totalSupply() public view virtual returns (uint256)

Returns the amount of tokens in existence.

RESERVE_POL_FEE_COLLECTOR

function RESERVE_POL_FEE_COLLECTOR() external view returns (address)

Returns the address of the POL fee collector, receiving the fees on this aToken.

The Fee is used to distribute among the BGT delegator.

Return Values

Name	Type	Description
[0]	address	Address of the Berachain fee collector contract.

UNDERLYING_ASSET_ADDRESS

function UNDERLYING_ASSET_ADDRESS() external view returns (address)

Returns the address of the underlying asset of this aToken (E.g. WETH for aWETH)

Return Values

Name	Type	Description
[0]	address	The address of the underlying asset

transferUnderlyingTo

function transferUnderlyingTo(address target, uint256 amount) external virtual

Transfers the underlying asset to target.

Used by the Pool to transfer assets in borrow(), withdraw() and flashLoan()

Parameters

Name	Type	Description
target	address	The recipient of the underlying
amount	uint256	The amount getting transferred

handleRepayment

function handleRepayment(address user, address onBehalfOf, uint256 amount) external virtual

Handles the underlying received by the aToken after the transfer has been completed.

The default implementation is empty as with standard ERC20 tokens, nothing needs to be done after the transfer is concluded. However in the future there may be aTokens that allow for example to stake the underlying to receive LM rewards. In that case, handleRepayment() would perform the staking of the underlying asset.

Parameters

Name	Type	Description
user	address	The user executing the repayment
onBehalfOf	address	The address of the user who will get his debt reduced/removed
amount	uint256	The amount getting repaid

permit

function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external

Allow passing a signed message to approve spending

_implements the permit function as for https://github.com/ethereum/EIPs/blob/8a34d644aacf0f9f8f00815307fd7dd5da07655f/EIPS/eip-2612.md_

Parameters

Name	Type	Description
owner	address	The owner of the funds
spender	address	The spender
value	uint256	The amount
deadline	uint256	The deadline timestamp, type(uint256).max for max deadline
v	uint8	Signature param
r	bytes32	Signature param
s	bytes32	Signature param

_transfer

function _transfer(address from, address to, uint256 amount, bool validate) internal virtual

Transfers the aTokens between two users. Validates the transfer (ie checks for valid HF after the transfer) if required

Parameters

Name	Type	Description
from	address	The source address
to	address	The destination address
amount	uint256	The amount getting transferred
validate	bool	True if the transfer needs to be validated, false otherwise

_transfer

function _transfer(address from, address to, uint128 amount) internal virtual

Overrides the parent _transfer to force validated transfer() and transferFrom()

Parameters

Name	Type	Description
from	address	The source address
to	address	The destination address
amount	uint128	The amount getting transferred

DOMAIN_SEPARATOR

function DOMAIN_SEPARATOR() public view returns (bytes32)

Overrides the base function to fully implement IAToken see EIP712Base.DOMAIN_SEPARATOR() for more detailed documentation

nonces

function nonces(address owner) public view returns (uint256)

Overrides the base function to fully implement IAToken see EIP712Base.nonces() for more detailed documentation

_EIP712BaseId

function _EIP712BaseId() internal view returns (string)

Returns the user readable name of signing domain (e.g. token name)

Return Values

Name	Type	Description
[0]	string	The name of the signing domain

rescueTokens

function rescueTokens(address token, address to, uint256 amount) external

Rescue and transfer tokens locked in this contract

Parameters

Name	Type	Description
token	address	The address of the token
to	address	The address of the recipient
amount	uint256	The amount of token to transfer

scaledBalanceOf

function scaledBalanceOf(address user) external view returns (uint256)

Returns the scaled balance of the user.

The scaled balance is the sum of all the updated stored balance divided by the reserve's liquidity index at the moment of the update

Parameters

Name	Type	Description
user	address	The user whose balance is calculated

Return Values

Name	Type	Description
[0]	uint256	The scaled balance of the user

getScaledUserBalanceAndSupply

function getScaledUserBalanceAndSupply(address user) external view returns (uint256, uint256)

Returns the scaled balance of the user and the scaled total supply.

Parameters

Name	Type	Description
user	address	The address of the user

Return Values

Name	Type	Description
[0]	uint256	The scaled balance of the user
[1]	uint256	The scaled total supply

scaledTotalSupply

function scaledTotalSupply() public view virtual returns (uint256)

Returns the scaled total supply of the scaled balance token. Represents sum(debt/index)

Return Values

Name	Type	Description
[0]	uint256	The scaled total supply

getPreviousIndex

function getPreviousIndex(address user) external view virtual returns (uint256)

Returns last index interest was accrued to the user's balance

Parameters

Name	Type	Description
user	address	The address of the user

Return Values

Name	Type	Description
[0]	uint256	The last index interest was accrued to the user's balance, expressed in ray