Verify with Hardhat

Make sure you've updated to @nomicfoundation/hardhat-verify@^2.0.14, see migrating notes if you have an existing project

Hardhat is a smart contracts development tool, perfect if you're familiar with Javascript/Typescript.

If you've yet to setup Hardhat, here's the official guide, the following steps are to setup the verification plugin.

Install

Via npm

npm i @nomicfoundation/hardhat-verify                               

Config

In hardhat.config.ts, import the plugin

import "@nomicfoundation/hardhat-verify";

Add your Etherscan key

config: HardhatUserConfig = {
  solidity: "0.8.28",
  networks: {
    sepolia: {
      url: `https://1rpc.io/sepolia`,
      accounts: [SEPOLIA_PRIVATE_KEY],
    },
  },
   etherscan: {
    apiKey: "YourEtherscanApiKey"
  }
};

Deploy and Verify

npx hardhat ignition deploy ./ignition/modules/Lock.ts --network sepolia --verify

Verify an Existing Contract

npx hardhat verify --network sepolia 0xdCBdBAA8404554502B433106e62728B659aCfE3b

Custom Chains

For super new Etherscan based explorers that are not supported by Hardhat yet, you can add them as a customChain in hardhat.config.ts ✨

etherscan: {
    apiKey: "YourEtherscanApiKey",
    customChains: [
    {
      network: "sonic",
      chainId: 146,
      urls: {
        apiURL: "https://api.etherscan.io/v2/api",
        browserURL: "https://sonicscan.org"
      }
    },
    {
      network: "katana",
      chainId: 146,
      urls: {
        apiURL: "https://api.etherscan.io/v2/api",
        browserURL: "https://sonicscan.org"
      }
    }
  ]
}

Migrating from V1

API keys from any other explorer (such as BscScan/Basescan/Arbiscan) have been deprecated ⚠️

This change largely affects the hardhat.config.ts file — good riddance to the long customChains entries for each explorer.

Update your config to a single Etherscan apiKey entry as per above.

This open source integration was shipped by @antico5 and the Hardhat team 🙌