Creating Your Own Currency on Ethereum: A Step-by-Step Guide

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Introduction to Token Creation on Ethereum

One of Ethereum's most popular features is the ability to create custom tokens. All tokens issued on Ethereum follow the ERC-20 standard, the same standard used by Ether itself. This compatibility ensures your tokens will work seamlessly with any wallet or exchange that supports Ethereum.

Developing an ERC-20 Smart Contract

Setting Up the Development Environment

We'll use Remix IDE (http://remix.ethereum.org/) for our development environment. Start by creating a new file named jasonToken.sol (you can choose any name).

The ERC-20 Interface Contract

pragma solidity ^0.5.0;

contract ERC20Interface {
    function totalSupply() public view returns (uint);
    function balanceOf(address tokenOwner) public view returns (uint balance);
    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);
    
    event Transfer(address indexed from, address indexed to, uint tokens);
    event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}

This interface defines the mandatory functions for any ERC-20 token:

Implementing SafeMath for Secure Calculations

Add the SafeMath contract below the ERC20 Interface code:

contract SafeMath {
    function safeAdd(uint a, uint b) public pure returns (uint c) {
        c = a + b;
        require(c >= a);
    }
    
    function safeSub(uint a, uint b) public pure returns (uint c) {
        require(b <= a);
        c = a - b;
    }
    
    function safeMul(uint a, uint b) public pure returns (uint c) {
        c = a * b;
        require(a == 0 || c / a == b);
    }
    
    function safeDiv(uint a, uint b) public pure returns (uint c) {
        require(b > 0);
        c = a / b;
    }
}

SafeMath prevents overflow errors by reverting transactions when arithmetic operations exceed safe limits.

Creating the Token Contract

Now we'll implement our JasonToken contract, which will mint 50 million tokens:

contract JasonToken is ERC20Interface, SafeMath {
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public _totalSupply;
    
    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;
    
    constructor() public {
        name = "JasonToken";
        symbol = "Jas";
        decimals = 1;
        _totalSupply = 50000000;
        balances[msg.sender] = _totalSupply;
        emit Transfer(address(0), msg.sender, _totalSupply);
    }
    
    function totalSupply() public view returns (uint) {
        return _totalSupply - balances[address(0)];
    }
    
    function balanceOf(address tokenOwner) public view returns (uint balance) {
        return balances[tokenOwner];
    }
    
    function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
        return allowed[tokenOwner][spender];
    }
    
    function approve(address spender, uint tokens) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        emit Approval(msg.sender, spender, tokens);
        return true;
    }
    
    function transfer(address to, uint tokens) public returns (bool success) {
        balances[msg.sender] = safeSub(balances[msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        emit Transfer(msg.sender, to, tokens);
        return true;
    }
    
    function transferFrom(address from, address to, uint tokens) public returns (bool success) {
        balances[from] = safeSub(balances[from], tokens);
        allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        emit Transfer(from, to, tokens);
        return true;
    }
}

Compiling and Deploying the Contract

Deployment Configuration

Set Remix to use "Injected Provider - MetaMask" and ensure you're connected to the Goerli test network. Verify you have sufficient ETH for deployment.

Deployment Process

  1. Select the correct contract (JasonToken) before deploying
  2. Monitor deployment status via MetaMask Activity
  3. View detailed information on Etherscan

👉 Learn more about smart contract deployment best practices

Verifying Contract Deployment

Once deployed:

  1. Confirm the contract appears in your wallet
  2. Check transaction details on Etherscan
  3. Verify the token balance in your connected wallet

Adding Your Token to MetaMask

To make your token visible in MetaMask:

  1. Click "Add Token"
  2. Enter your contract address
  3. Confirm token details

👉 Discover advanced Ethereum wallet management techniques

Token Distribution

Now you're ready to:

FAQ Section

What is the ERC-20 standard?

ERC-20 is a technical standard for creating fungible tokens on Ethereum, ensuring compatibility across wallets and exchanges.

Why use SafeMath?

SafeMath prevents arithmetic overflow/underflow vulnerabilities that could lead to token loss or creation.

How much does it cost to deploy a token?

Deployment costs vary based on network congestion, but typically range from $50-$200 in gas fees.

Can I change token parameters after deployment?

No, token name, symbol, and total supply are immutable once deployed.

How do I get test ETH for deployment?

Use Goerli faucets to obtain free test ETH for development purposes.

What's the difference between decimals and total supply?

Decimals determine divisibility (e.g., 18 decimals = 1 token = 10^18 smallest units), while total supply is the whole number of tokens created.