EzeniIa

ERC-20 Token Guide

Learn to create fungible tokens on Ethereum using Solidity and modern development tools.

ERC-20 Guide Outline

1. Introduction
2. Environment Setup
3. Writing the Token
4. Security
5. Deployment

1. What Are ERC-20 Tokens?

ERC-20 is a standard interface for fungible tokens on Ethereum, defining functions and events for token operations like transfers and approvals.

"ERC-20 provides a uniform way to interface with Ethereum tokens."

Why Learn ERC-20?

Build custom token economies
Create staking rewards programs
Develop token-gated services

Development Setup

Install Ethereum tooling:

npx hardhat
npm install @openzeppelin/contracts

✅

OpenZeppelin SDK

Use npm install @openzeppelin/contracts to leverage existing ERC-20 implementations
Local Network

Test with npx hardhat node before deploying on mainnet

ERC-20 Implementation

{`pragma solidity ^0.8.0; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; contract MyToken is ERC20 { constructor() ERC20("MyToken", "MTK") { _mint(msg.sender, 1000000 * 10**decimals()); } } `}

🔧

This creates a basic ERC-20 token with name 'MyToken' and symbol 'MTK', minting 1 million tokens.

Key Functions

transfer(): Move tokens between addresses
approve(): Allow spending from another account
totalSupply(): Get total tokens in circulation
balanceOf(): Check address balance

Security Best Practices

Deploy Token

Deployment Script

Create scripts/deploy.js:

async function main() {
  const [deployer] = await ethers.getSigners();
  console.log("Deploying from:", deployer.address);

  const Token = await ethers.getContractFactory("MyToken");
  const token = await Token.deploy();
  await token.deployed();

  console.log("Token deployed to:", token.address);
}

main()
  .then(() => process.exit(0))
  .catch(error => {
    console.error(error);
    process.exit(1);
  });

Gas Optimization

Use npx hardhat deploy with the --network flag:

hardhat deploy --network localhost scripts/deploy.js

Next Step: Token Integration

Use your token address in DApps or connect to MetaMask for user access.