# PeripheryPayments [Git Source](https://github.com/yearn/Yearn-ERC4626-Router/blob/68165774ec8858b43db24620756402def14b7ec1/src/external/PeripheryPayments.sol) Immutable state used by periphery contracts Largely Forked from https://github.com/Uniswap/v3-periphery/blob/main/contracts/base/PeripheryPayments.sol Changes: no interface no inheritdoc add immutable WETH9 in constructor instead of PeripheryImmutableState receive from any address Solmate interfaces and transfer lib casting add approve, wrapWETH9 and pullToken ## State Variables ### WETH9 ```solidity IWETH9 public immutable WETH9; ``` ## Functions ### constructor ```solidity constructor(IWETH9 _WETH9); ``` ### receive ```solidity receive() external payable; ``` ### approve ```solidity function approve(ERC20 token, address to, uint256 amount) public payable; ``` ### unwrapWETH9 ```solidity function unwrapWETH9(uint256 amountMinimum, address recipient) public payable; ``` ### wrapWETH9 ```solidity function wrapWETH9() public payable; ``` ### pullToken ```solidity function pullToken(ERC20 token, uint256 amount, address recipient) public payable; ``` ### sweepToken ```solidity function sweepToken(ERC20 token, uint256 amountMinimum, address recipient) public payable; ``` ### refundETH ```solidity function refundETH() external payable; ```