# ETH Faucet Contract

By [Moei](https://paragraph.com/@0xmoei-2) · 2023-04-14

---

    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    
    contract FaucetBy0xMoei {
        address payable public admin;
        uint256 public maxWithdrawalPerDay = 0.3 ether;
        uint256 public withdrawalFee = 0.001 ether;
        uint256 public lastWithdrawalBlock;
        mapping(address => uint256) public lastWithdrawalTimestamps;
        mapping(address => bool) public whitelist;
        
        event Withdrawal(address indexed user, uint256 amount, uint256 timestamp);
        event Deposit(address indexed user, uint256 amount, uint256 timestamp);
        event MaxWithdrawalPerDayChanged(uint256 newMaxWithdrawalPerDay, uint256 timestamp);
        event WithdrawalFeeChanged(uint256 newWithdrawalFee, uint256 timestamp);
        event WhitelistAdded(address indexed user, uint256 timestamp);
        event WhitelistRemoved(address indexed user, uint256 timestamp);
        
        constructor() {
            admin = payable(msg.sender);
            lastWithdrawalBlock = block.number;
        }
        
        modifier onlyAdmin() {
            require(msg.sender == admin, "Only admin can perform this action");
            _;
        }
        
        function withdraw() external {
            require(lastWithdrawalTimestamps[msg.sender] + 1 days <= block.timestamp, "You can only withdraw once per day");
            require(address(this).balance >= maxWithdrawalPerDay, "Insufficient balance");
            require(block.number > lastWithdrawalBlock, "Can only withdraw once per block");
            require(msg.sender != admin, "Admin cannot withdraw");
            require(!whitelist[msg.sender], "Address is whitelisted for higher withdrawal limit");
            
            lastWithdrawalTimestamps[msg.sender] = block.timestamp;
            lastWithdrawalBlock = block.number;
            uint256 withdrawalAmount = maxWithdrawalPerDay - withdrawalFee;
            payable(msg.sender).transfer(withdrawalAmount);
            payable(admin).transfer(withdrawalFee);
            emit Withdrawal(msg.sender, withdrawalAmount, block.timestamp);
        }
        
        function setMaxWithdrawalPerDay(uint256 newMaxWithdrawalPerDay) external onlyAdmin {
            require(newMaxWithdrawalPerDay > 0, "Max withdrawal per day must be greater than zero");
            maxWithdrawalPerDay = newMaxWithdrawalPerDay;
            emit MaxWithdrawalPerDayChanged(newMaxWithdrawalPerDay, block.timestamp);
        }
        
        function setWithdrawalFee(uint256 newWithdrawalFee) external onlyAdmin {
            withdrawalFee = newWithdrawalFee;
            emit WithdrawalFeeChanged(newWithdrawalFee, block.timestamp);
        }
        
        function addToWhitelist(address user) external onlyAdmin {
            whitelist[user] = true;
            emit WhitelistAdded(user, block.timestamp);
        }
        
        function removeFromWhitelist(address user) external onlyAdmin {
            whitelist[user] = false;
            emit WhitelistRemoved(user, block.timestamp);
        }
        
        function withdrawBalance() external onlyAdmin {
            admin.transfer(address(this).balance);
        }
        
        receive() external payable {
            emit Deposit(msg.sender, msg.value, block.timestamp);
        }
        
        function deposit() external payable {
            emit Deposit(msg.sender, msg.value, block.timestamp);
        }
    }

---

*Originally published on [Moei](https://paragraph.com/@0xmoei-2/eth-faucet-contract)*