Deploying your own ERC-20 token

Compiling and deploying an ERC-20 contract on Sepolia testnet using Hardhat in this assignment.

Setting up the ERC-20 Project

Follow the instructions here to get an API key for Sepolia (not Goerli).
Take note of the following:
- npx commands are always run in the project root directory. Don't run them inside subdirectories.
- Never upload your .env files to Github. It has your private key and Alchemy API key. These can be misused.
Create a new directory and enter it.
```
mkdir my-token
cd my-token
```
Initialize a new Node.js project.
```
npm init -y
```
The directory should contain a single file called package.json.
Install Hardhat by running the following command in the my-token directory.
```
npm install --save-dev hardhat
```
The package.json file will now have a hardhat section under devDependencies.
Create a Hardhat project by running the following command.
```
npx hardhat
```
Select Create a JavaScript project and choose Y for installing @nomicfoundation/hardhat-toolbox.

The directory will have a file called hardhat.config.js with the following contents.
```
require("@nomicfoundation/hardhat-toolbox");

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
solidity: "0.8.24",
};
```
Create a file called .env in the project directory with the following contents.
```
API_URL = "https://eth-sepolia.g.alchemy.com/v2/your-api-key"
PRIVATE_KEY = "your-metamask-private-key"
```
Follow these instructions to export your private key from Metamask. The API_URL needs to be copied from your Alchemy account.

NOTE: If you are going to push the project code to a public Github/Gitlab repository, remember to add the .env file to your .gitignore.

Update the hardhat.config.js file to have the following content.

require("@nomicfoundation/hardhat-toolbox");
require('dotenv').config();

const { API_URL, PRIVATE_KEY } = process.env;

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
    solidity: "0.8.24",
    defaultNetwork: "sepolia",
    networks: {
        hardhat: {},
        sepolia: {
            url: API_URL,
            accounts: [`0x${PRIVATE_KEY}`]
        }
    },
};

Your ERC-20 token will be based on the implementation by OpenZeppelin. Install the Node.js package containing OpenZeppelin's contracts by running the following command in the project directory.
```
npm install @openzeppelin/contracts
```
The installed contracts can be found in the node_modules directory in your project directory. The path will be node_modules/@openzeppelin/contracts/. We will be inheriting the ERC-20 implementation at node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol.

Deploying the ERC-20 Contract

The project directory contains a contracts directory with a Lock.sol file. Delete it.
Create a new file in the contracts directory called MyToken.sol.

Copy and paste the following code into MyToken.sol after replacing XYZ with your initials. For example, my initials would be KSA.

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract XYZToken is ERC20 {
    uint constant _initial_supply = 100 * (10**18);

    /* ERC 20 constructor takes in two strings:
     1. The name of your token name
     2. A symbol for your token
    */
    constructor() ERC20("XYZ Token", "XYZT") {
        _mint(msg.sender, _initial_supply);
    }
}

Compile the contract by running the following command.
```
npx hardhat compile
```
You should see a message saying Compiled 1 Solidity file successfully.
Create a directory called scripts
```
mkdir scripts
```

Create a file called deploy.js in the scripts directory with the following content. Note: Change "XYZToken" to the name of your contract.

async function main() {
    const MyToken = await ethers.getContractFactory("XYZToken");

    const my_token_promise = await MyToken.deploy();
    const my_token = await my_token_promise.waitForDeployment();
    const my_token_address = await my_token.getAddress();
    console.log("ERC-20 contract deployed to address:", my_token_address);
}

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

Deploy the contract by running the following command.
```
npx hardhat run scripts/deploy.js --network sepolia
```
You should see a message of the following form. The address will be different in your case.
```
ERC-20 contract deployed to address: 0xbb8Ab9564596Ccbfe0C6eD49D7FdB056eE741CE5
```
Go to https://sepolia.etherscan.io/token/[Your Token Address] to see the token details. Notice that you have to enter the address of the newly created token in the URL.
Follow the instructions in sections 4.1, and 4.2 here to deploy an ERC-20 token contract.
Follow the instructions in section 4.3 here to transfer some your tokens to a different addresss.
My Sepolia ERC-20 contract: HERE
Sepolia Transaction transferring my token: HERE

ksahilan/ERC-20-Token

Deploying your own ERC-20 token

Setting up the ERC-20 Project

Deploying the ERC-20 Contract