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Hardhat: Deploying a Smart Contract

Hardhat is a versatile development environment specifically created for building smart contracts on the Ethereum network. It offers flexibility, allowing developers to easily integrate and extend its functionalities.

Install Dependencies​

info

Before proceeding, you need to install Node.js (we'll use v16.x) and the npm package manager.

Create Hardhat Project​

To create a new project, navigate to your project directory and run:

$ npx hardhat

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888    888     "88b 888P"  d88" 888 888 "88b     "88b 888
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888    888 "Y888888 888     "Y88888 888  888 "Y888888  "Y888

👷 Welcome to Hardhat v2.9.3 👷‍

? What do you want to do? …
  Create a basic sample project
❯ Create an advanced sample project
  Create an advanced sample project that uses TypeScript
  Create an empty hardhat.config.js
  Quit

By following the prompts, you will be able to create a new project structure in your chosen directory. To configure your Hardhat project, you can refer to the Hardhat config page, which provides a list of configuration options that can be specified in the hardhat.config.js file. One crucial configuration is setting the defaultNetwork entry to point to your desired JSON-RPC network.

module.exports = {
  defaultNetwork: "testnet",
  networks: {
    hardhat: {
    },
    testnet: {
      url: "https://node1.testnet.treasurenet.io:8545",
      accounts: [privateKey1, privateKey2, ...]
    }
  }
}

To ensure you are targeting the correct network, you can query for a list of accounts available to you from your default network provider:

$ npx hardhat accounts
0xf39Fd6e51aad88F6F4ce6aB88273c5d6ba293358

Deploying a Smart Contract​

A default smart contract, written in Solidity, has already been provided under contracts/Greeter.sol:

pragma solidity ^0.8.0;

import "hardhat/console.sol";

contract Greeter {
    string private greeting;

    constructor(string memory _greeting) {
        console.log("Deploying a Greeter with greeting:", _greeting);
        greeting = _greeting;
    }

    function greet() public view returns (string memory) {
        return greeting;
    }

    function setGreeting(string memory _greeting) public {
        console.log("Changing greeting from '%s' to '%s'", greeting, _greeting);
        greeting = _greeting;
    }
}

This contract allows you to set and query a string greeting.

Hardhat also provides a script to deploy smart contracts to a target network; this can be invoked via the following command, targeting your default network:

npx hardhat run scripts/deploy.js

Hardhat also lets you manually specify a target network via the --network your-network flag:

npx hardhat run --network {{ $themeConfig.project.rpc_url_testnet }} scripts/deploy.js

Finally, try running a Hardhat test:

$ npx hardhat test
Compiling 1 file with 0.8.4
Compilation finished successfully


  Greeter
Deploying a Greeter with greeting: Hello, world!
Changing greeting from 'Hello, world!' to 'Hola, mundo!'
    ✓ Should return the new greeting once it's changed (803ms)


  1 passing (805ms)