Create an ERC20 token

In this tutorial you'll build and deploy an ERC20 token to ZKsync Sepolia Testnet

This tutorial shows you how to deploy and interact with an ERC20 token on ZKsync Sepolia Testnet.

This is what you're going to do:

Build an ERC20 token smart contract with additional custom logic

Deploy the smart contract to the ZKsync Sepolia Testnet using Remix or Atlas.

Prerequisites

  1. Before you start, make sure that you’ve configured the ZKsync Sepolia Testnet in your wallet.
  2. Have at least 0.5 ZKsync Sepolia Testnet ETH. If you need more, use one of the faucets.

To complete this tutorial you'll use either Atlas or Remix. Select your preferred tool:

Custom ERC20 token code

ERC20 tokens are a standard for fungible tokens, which can be traded and represent a fixed value. You’ve used ERC20 tokens if you’ve transacted with USDC, DAI, USDT, LINK or UNI.

The ERC20 token we’re going to deploy will allow users to mint and burn tokens. The entire smart contract code is as follows:

// SPDX-License-Identifier: Unlicensed
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";

contract TestToken is ERC20, Ownable, ERC20Burnable {
    constructor(string memory name, string memory symbol) ERC20(name, symbol) {
        _mint(msg.sender, 100 * 10 ** decimals());
    }

    function mint(address to, uint256 amount) public onlyOwner {
        _mint(to, amount);
    }
}
ZKsync Era is EVM compatible, so you can use existing popular libraries like OpenZeppelin.

The most important features are:

  • Ownable : this extension sets the deployer account as owner of the smart contract. It also introduces the onlyOwner modifier that restricts the execution of certain functions to the owner of the contract.
  • ERC20Burnable: this extension adds the burn and burnFrom functions to the smart contract. These functions destroy tokens from a given account.
  • constructor: called on deployment, the constructor will assign the given name and symbol to the token and mint 100 units of it to the account that deployed the contract.
  • mint : this function creates new token units to a given account. It uses the onlyOwner modifier so it can only be called from the owner account.

Deploy the smart contract

Atlas is a browser-based IDE with an integrated AI assistant that allows you to write, test and deploy smart contracts directly from your browser. Click the button below to open the project in Atlas.

Open smart contract in Atlas

You can see the contract in the Atlas code editor. In the right sidebar, make sure the selected network is “ZKsync Sepolia Testnet“ and click on "Deploy" to trigger the smart contract compilation and deployment.

Behind the scenes, Atlas is using the ZKsync Era custom solidity compiler (named zksolc ) to generate ZKEVM compatible bytecode. Learn more about ZKsync custom compilers.

ERC20 interact script in Atlas

Once compiled sign the transaction with your wallet and wait until its processed. You’ll see the contract in the “Deployed contracts” section.

Interact with the ERC20 contract

In the scripts folder you can find the mint-token.ts script containing the following code:

import { AtlasEnvironment } from "atlas-ide";
import TokenArtifact from "../artifacts/TestToken";
import * as ethers from "ethers";

// Address of the ERC20 token contract
const TOKEN_CONTRACT_ADDRESS = ""
// Wallet that will receive tokens
const RECEIVER_WALLET    = "";
// Amount of tokens to mint in ETH format, e.g. 1.23
const TOKEN_AMOUNT    = "";

export async function main (atlas: AtlasEnvironment) {
  const provider = new ethers.providers.Web3Provider(atlas.provider);
  const wallet = provider.getSigner();

  // initialise token contract with address, abi and signer
  const tokenContract= new ethers.Contract(
    TOKEN_CONTRACT_ADDRESS,
    TokenArtifact.TestToken.abi,
    wallet
  );

  console.log("Minting tokens...");
  const tx = await tokenContract.mint(
    RECEIVER_WALLET,
    ethers.utils.parseEther(TOKEN_AMOUNT)
  );
  await tx.wait();


  console.log("Success!");
  console.log(`
    The account ${RECEIVER_WALLET} now has
    ${await tokenContract.balanceOf(RECEIVER_WALLET)} tokens`
  );

}

This scripts uses ethers to interact with the contract we’ve just deployed.

Existing libraries like ethers , viem and web3.js can be used to interact with smart contracts deployed on ZKsync.

Fill the following variables:

  • TOKEN_CONTRACT_ADDRESS: the contract address of the ERC20 token we just deployed.
  • RECEIVER_WALLET: address of a different account that will receive new tokens.
  • TOKEN_AMOUNT: the amount of tokens we’ll send to the account.

With the mint-token.ts file open in the Atlas editor, click on the “Deploy” button to run the script and see the output in the terminal.

ERC20 interact script in Atlas

To confirm the account has received the tokens, visit the ZKsync Sepolia Testnet explorer and search the receiver wallet address. You’ll see the new token balance in the assets table:

ERC20 tokens in account balance

Custom ERC20 token code

ERC20 tokens are a standard for fungible tokens, which can be traded and represent a fixed value. You’ve used ERC20 tokens if you’ve transacted with USDC, DAI, USDT, LINK or UNI.

The ERC20 token we’re going to deploy will allow users to mint and burn tokens. The entire smart contract code is as follows:

// SPDX-License-Identifier: Unlicensed
pragma solidity ^0.8.19;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";

contract TestToken is ERC20, Ownable, ERC20Burnable {
    constructor(string memory name, string memory symbol)
      ERC20(name, symbol) Ownable(msg.sender) {
        _mint(msg.sender, 100 * 10 ** decimals());
    }

    function mint(address to, uint256 amount) public onlyOwner {
        _mint(to, amount);
    }
}
ZKsync Era is EVM compatible, so you can use existing popular libraries like OpenZeppelin.

The most important features are:

  • Ownable : this extension sets the deployer account as owner of the smart contract. It also introduces the onlyOwner modifier that restricts the execution of certain functions to the owner of the contract.
  • ERC20Burnable: this extension adds the burn and burnFrom functions to the smart contract. These functions destroy tokens from a given account.
  • constructor: called on deployment, the constructor will assign the given name and symbol to the token and mint 100 units of it to the account that deployed the contract.
  • mint : this function creates new token units to a given account. It uses the onlyOwner modifier so it can only be called from the owner account.

Deploy the smart contract

The Remix IDE is an open-source web and desktop application that supports Ethereum smart contract development and deployment, offering tools for writing, testing, debugging, and deploying smart contracts written in Solidity to EVM compatible protocols.

Enable the Remix ZKsync plugin

To deploy smart contracts to ZKsync via Remix you need to enable the ZKsync plugin.

  1. Visit the Remix website
  2. Click on the “🔌 Plugin Manager” button in the bottom-left corner
  3. Search “zksync” and click on the "Activate" button.

Enable ZKsync plugin in Remix

Once activated, you’ll see a new menu item with the ZKsync logo. Click on it to see the different options to compile, deploy, and interact with smart contracts on ZKsync.

To open this project in Remix, use the “Clone” option from the file explorer to import it from the following GitHub repository:https://github.com/ZKsync-Community-Hub/zksync-quickstart-remix

Clone repo in Remix

Once the project is imported, open the contracts/TestToken.sol file. To compile the contract, click on the ZKsync plugin on the left menu and then "Compile TestToken.sol". If you get a popup message requesting permissions to access ACCESS TO "WRITEFILE" OF "FILE MANAGER", click on Accept.

Behind the scenes, Remix is using the ZKsync Era custom Solidity compiler (named zksolc ) to generate ZKEVM compatible bytecode. Learn more about ZKsync custom compilers.

We will use our wallet’s configured network to connect and deploy our smart contract so make sure your wallet is currently connected to the ZKsync Sepolia Testnet. In Remix, under the Environment Section, select “Wallet” and click on “Connect Wallet”.

To deploy the contract, click on “Deploy” and sign the transaction on your wallet. Congratulations, your ERC20 token contract is now deployed on ZKsync Sepolia Testnet!

Interact with the ERC20 contract

In the scripts folder you can find the mint-token.ts script containing the following code:

import {ethers} from "ethers";

// Address of the ERC20 token contract
const TOKEN_CONTRACT_ADDRESS = ""
// Wallet that will receive tokens
const RECEIVER_WALLET    = "";
// Amount of tokens to mint in ETH format, e.g. 1.23
const TOKEN_AMOUNT    = "123.55";

(async () => {
  try {

  // Note that the script needs the ABI which is generated from the compilation artifact.
  // Make sure contract is compiled for ZKsync and artifacts are generated
  const artifactsPath = `browser/contracts/artifacts/TestToken.json` // Change this for different path

  const metadata = JSON.parse(await remix.call('fileManager', 'getFile', artifactsPath))

  // 'web3Provider' is a remix global variable object
  const signer = (new ethers.providers.Web3Provider(web3Provider)).getSigner(0)

  // initialise token contract with address, abi and signer
  const tokenContract= new ethers.Contract(TOKEN_CONTRACT_ADDRESS, metadata.abi, signer);

  console.log("Minting tokens...");
  const tx = await tokenContract.mint(
    RECEIVER_WALLET,
    ethers.utils.parseEther(TOKEN_AMOUNT)
  );
  console.log(`Mint transaction is ${tx.hash}`)
  await tx.wait();
  console.log("Success!");

  const balance = await tokenContract.balanceOf(RECEIVER_WALLET)

  console.log(`The account ${RECEIVER_WALLET} now has ${balance} tokens`)

  } catch (e) {
    console.log(e.message)
  }
})()

This scripts uses ethers to interact with the contract we’ve just deployed.

Existing libraries like ethers , viem and web3.js can be used to interact with smart contracts deployed on ZKsync.

Fill the following variables:

  • TOKEN_CONTRACT_ADDRESS: the contract address of the ERC20 token we just deployed.
  • RECEIVER_WALLET: address of a different account that will receive new tokens.
  • TOKEN_AMOUNT: the amount of tokens we’ll send to the account.

With the mint-token.ts file open in the editor, click on the “▶️” button to run the script and see the output in the terminal.

ERC20 interact script in Remix

To confirm the account has received the tokens, visit the ZKsync Sepolia Testnet explorer and search the receiver wallet address. You’ll see the new token balance in the assets table:

ERC20 tokens in account balance

Takeaways

  • ZKsync Era is EVM compatible and supports existing smart contract libraries like OpenZeppelin
  • Use popular libraries like ethers , viem, or web3.js to interact with smart contracts deployed on ZKsync Era.
The ERC20 token code is provided “as is” without any express or implied warranties.
  • The regulatory regime governing digital assets is still developing and is unclear in many jurisdictions.
  • ERC20 tokens may possess unique legal, tax, and market risks, so it is up to you to determine which, if any, laws apply to your deployment of ERC20 tokens.
  • The developers and publishers of this software disclaim any liability for any legal issues that may arise from its use.

Next steps


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