hardhat.config.js

require('@nomiclabs/hardhat-waffle');
require('@nomiclabs/hardhat-ethers');
require('hardhat-gas-reporter');
require("@nomiclabs/hardhat-etherscan");
require('dotenv').config();

const settings = {
  optimizer: {
    enabled: true,
    runs: 200,
  },
};

function mnemonic() {
  return [process.env.PRIVATE_KEY, process.env.PRIVATE_KEY1, process.env.PRIVATE_KEY2];
}

/**
 * @type import('hardhat/config').HardhatUserConfig
 */
module.exports = {
  solidity: {
    compilers: [
      { version: '0.8.8',  settings },
      { version: '0.7.6',  settings },
      { version: '0.6.11', settings },
      { version: '0.5.16', settings },
      { version: '0.8.20', settings },
    ],
  },
  etherscan: {
    apiKey: {
      optimisticEthereum: 'xxx'
    },
  },
  networks: {
    localhost: {
      url: 'http://localhost:8545',
      //gasPrice: 125000000000,  // you can adjust gasPrice locally to see how much it will cost on production
      /*
        notice no mnemonic here? it will just use account 0 of the hardhat node to deploy
        (you can put in a mnemonic here to set the deployer locally)
      */
    },
    rinkeby: {
      url: 'https://rinkeby.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
      accounts: mnemonic(),
    },
    kovan: {
      url: 'https://kovan.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
      accounts: mnemonic(),
    },
    mainnet: {
      url: 'https://mainnet.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
      accounts: mnemonic(),
    },
    ropsten: {
      url: 'https://ropsten.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
      accounts: mnemonic(),
    },
    matic: {
      url: 'https://polygon-mainnet.infura.io/v3/' + process.env.INFURA_ID,
      accounts: mnemonic()
    },
    optim: {
      url: "https://optimism-mainnet.infura.io/v3/" + process.env.INFURA_ID,
      accounts: mnemonic()
    },
  },
  gasReporter: {
    currency: 'USD',
    coinmarketcap: process.env.COINMARKETCAP,
    gasPrice: 200,
  },
  mocha: {
    timeout: 20000
  },
};