erc20-patterns

ERC-20 Implementation & Integration Patterns

Standard Interface (EIP-20)

interface IERC20 {
    function totalSupply() external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    function transfer(address to, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address from, address to, uint256 amount) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

OpenZeppelin Base Token

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {ERC20Permit} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Permit.sol";
import {ERC20Burnable} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
import {ERC20Pausable} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Pausable.sol";
import {ERC20Capped} from "@openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";

contract MyToken is ERC20, ERC20Permit, ERC20Burnable, ERC20Pausable, ERC20Capped, Ownable {
    constructor(
        string memory name_,
        string memory symbol_,
        uint256 cap_
    ) ERC20(name_, symbol_) ERC20Permit(name_) ERC20Capped(cap_) Ownable(msg.sender) {
        _mint(msg.sender, cap_ / 10); // 10% initial supply
    }

    function mint(address to, uint256 amount) external onlyOwner {
        _mint(to, amount);
    }

    function pause() external onlyOwner { _pause(); }
    function unpause() external onlyOwner { _unpause(); }

    // Required overrides for multiple inheritance
    function _update(address from, address to, uint256 value)
        internal
        override(ERC20, ERC20Pausable, ERC20Capped)
    {
        super._update(from, to, value);
    }
}