WETHNativeConverter

Author: See https://github.com/agglayer/vault-bridge

State Variables

_WETH_NATIVE_CONVERTER_STORAGE

The storage slot at which WETHNativeConverter storage starts, following the EIP-7201 standard.

Calculated as keccak256(abi.encode(uint256(keccak256("agglayer.vault-bridge.WETHNativeConverter.storage")) - 1)) & ~bytes32(uint256(0xff)).

bytes32 private constant _WETH_NATIVE_CONVERTER_STORAGE =
    hex"f9565ea242552c2a1a216404344b0c8f6a3093382a21dd5bd6f5dc2ff1934d00";

Functions

onlyIfGasTokenIsEth

modifier onlyIfGasTokenIsEth();

constructor

constructor();

initialize

function initialize(
    address owner_,
    address customToken_,
    address underlyingToken_,
    address lxlyBridge_,
    uint32 layerXNetworkId_,
    uint256 nonMigratableBackingPercentage_,
    address migrationManager_,
    uint256 nonMigratableGasBackingPercentage_
) external initializer;

nonMigratableGasBackingPercentage

function nonMigratableGasBackingPercentage() public view returns (uint256);

_getWETHNativeConverterStorage

function _getWETHNativeConverterStorage() private pure returns (WETHNativeConverterStorage storage $);

migratableGasBacking

function migratableGasBacking() public view returns (uint256);

migrateGasBackingToLayerX

It is known that this can lead to WETH not being able to perform withdrawals, because of a lack of gas backing.

However, this is acceptable, because WETH is a vault backed token so its backing should actually be staked.

Users can still bridge WETH back to Layer X to receive wETH or ETH.

This special function allows the NativeConverter owner to migrate the gas backing of the WETH Custom Token

It simply takes the amount of gas token from the WETH contract

and performs the migration using a special CrossNetworkInstruction called _1_WRAP_GAS_TOKEN_AND_COMPLETE_MIGRATION

It instructs vbETH on Layer X to first wrap the gas token and then deposit it to complete the migration.

function migrateGasBackingToLayerX(uint256 amount)
    external
    whenNotPaused
    onlyIfGasTokenIsEth
    onlyRole(MIGRATOR_ROLE)
    nonReentrant;

receive

receive() external payable whenNotPaused onlyIfGasTokenIsEth;

setNonMigratableGasBackingPercentage

function setNonMigratableGasBackingPercentage(uint256 nonMigratableGasBackingPercentage_)
    external
    onlyRole(DEFAULT_ADMIN_ROLE)
    nonReentrant;

Events

NonMigratableGasBackingPercentageSet

event NonMigratableGasBackingPercentageSet(uint256 nonMigratableGasBackingPercentage_);

Errors

FunctionNotSupportedOnThisNetwork

error FunctionNotSupportedOnThisNetwork();

InvalidNonMigratableGasBackingPercentage

error InvalidNonMigratableGasBackingPercentage();

Structs

WETHNativeConverterStorage

Storage of WETHNativeConverter contract.

It's implemented on a custom ERC-7201 namespace to reduce the risk of storage collisions when using with upgradeable contracts.

Note: storage-location: erc7201:agglayer.vault-bridge.WETHNativeConverter.storage

struct WETHNativeConverterStorage {
    WETH _weth;
    bool _gasTokenIsEth;
    uint256 nonMigratableGasBackingPercentage;
}

Technical Reference