hardhat.config.js

/**
 * @type import('hardhat/config').HardhatUserConfig
 */

require("dotenv").config();
require("@nomiclabs/hardhat-ethers");
require("@nomiclabs/hardhat-etherscan");

const { INFURA_API_KEY, PRIVATE_KEY, ETHERSCAN_API_KEY } = process.env;

module.exports = {
  solidity: {
    version: "0.8.4",
    settings: {
      optimizer: {
        enabled: true,
      },
    },
  },
  defaultNetwork: "mainnet",
  networks: {
    hardhat: {},
    localhost: {
      url: "http://127.0.0.1:8545",
    },
    mainnet: {
      url: `https://mainnet.infura.io/v3/${INFURA_API_KEY}`,
      chainId: 1,  // optional variable
      gasPrice: 2000000000,  // optional variable
      accounts: [`0x${PRIVATE_KEY}`],
    },
    goerli: {
      url: `https://goerli.infura.io/v3/${INFURA_API_KEY}`,
      chainId: 5,
      gasPrice: 20000000000,
      accounts: [`0x${PRIVATE_KEY}`],
    },
    mainnet_bsc: {
      url: "https://bsc-dataseed.binance.org",
      chainId: 56,
      gasPrice: 20000000000,
      accounts: [`0x${PRIVATE_KEY}`],
    },
    testnet_bsc: {
      url: "https://data-seed-prebsc-1-s1.binance.org:8545",
      chainId: 97,
      gasPrice: 20000000000,
      accounts: [`0x${PRIVATE_KEY}`],
    },
    mainnet_polygon: {
      url: "https://matic-mainnet.chainstacklabs.com",
      chainId: 137,
      gasPrice: 2000000000,
      accounts: [`0x${PRIVATE_KEY}`],
    },
    testnet_polygon: {
      url: "https://matic-mumbai.chainstacklabs.com",
      chainId: 80001,
      gasPrice: 2000000000,
      accounts: [`0x${PRIVATE_KEY}`],
    },
  },
  etherscan: {
    apiKey: ETHERSCAN_API_KEY,
  },
};