Cronos Hardhat Contract Verification plugin

Hardhat plugin for integration with Cronoscan and Cronos Testnet Explorer's contract verification service.

This plugin needs to be used in conjunction with the hardhat-verify plugin.

Features

Verify the source code for your Solidity contracts on Cronoscan and Cronos Testnet Explorer.

Installation

1. Install the package

# Install hardhat-etherscan plugin
npm install --save-dev @nomicfoundation/hardhat-verify

# Install hardhat-cronoscan plugin
npm install --save-dev @cronos-labs/hardhat-cronoscan

2. Import the plugins

In your hardhat.config.ts, import the two plugins:

...
import "@nomiclabs/hardhat";
import "@nomicfoundation/hardhat-verify";
import "@cronos-labs/hardhat-cronoscan";
...

3. Define your API key

In your project's hardhat.config.ts, append to your existing configurations:

const config: HardhatUserConfig = {
  etherscan: {
    apiKey: {
      cronos: "{YOUR_CRONOSCAN_API_KEY}",
    },
  },
};

Replace {YOUR_CRONOSCAN_API_KEY} with your Cronoscan API key. You can generate your API key by creating an Cronoscan account and generate it here.

Cronos Testnet Explorer does not require any API key.

Tasks

This plugin add the Cronos network to the verify task provided by hardhat-verify. With this plugin the verify task is able to verify Cronos contracts through Cronoscan and Cronos Testnet Explorer's service.

Usage

In your existing hardhat project, run the following commands

Mainnet

npx hardhat verify --network cronos DEPLOYED_CONTRACT_ADDRESS "Constructor argument 1"

Testnet

npx hardhat verify --network cronosTestnet DEPLOYED_CONTRACT_ADDRESS "Constructor argument 1"

For more advance usage, please refer to hardhat-verify's documentation.

Required plugins

• hardhat-verift

Configuration

This plugin extends the HardhatUserConfig's EtherscanConfig object with the Cronoscan configurations.

You should define your own Cronoscan API key. Cronos Testnet Explorer does not require any API key. However, hardhat-verify pluging still require you provide a dummy API key for it.

This is an example of how to set it. Replace {YOUR_CRONOSCAN_API_KEY} with your Cronoscan API key:

const config: HardhatUserConfig = {
  etherscan: {
    apiKey: {
      cronos: "{YOUR_CRONOSCAN_API_KEY}",
    },
    customChains: [
      // You can keep other Etherscan custom chains configurations as long as 
      // they do not overwrite the "cronos" network and "cronosTestnet" network
      {
        network: "MyEVMChain"
        ...
      }
    }]
  },
};

export default config;

Using Hardhat without this Plugin

This plugin appends etherscan configurations for Cronoscan (Cronos Mainnet) and Cronos Testnet Explorer for you. If you do not want to use this plugin, here is a simple hardhat.config.ts that can provide the same functionalities.

...
import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-verify";
...

const config: HardhatUserConfig = {
  ...
  networks: {
    cronos: {
      chainId: 25,
      url: "https://evm.cronos.org",
      accounts: ["{YOUR_DEPLOYER_PRIVATE_KEY}"]
    }
    cronosTestnet: {
      chainId: 338,
      url: "https://evm-t3.cronos.org",
      accounts: ["{YOUR_DEPLOYER_PRIVATE_KEY}"]
    }
  },
  etherscan: {
    apiKey: {
      cronos: "{YOUR_CRONOSCAN_API_KEY}",
      // No API key is required for Cronos Testnet Explorer but hardhat-verify requires an API key
      // must be present so a dummy string is provided
      cronosTestnet: "no-api-key-required",
    },
    customNetworks: [
      // You can keep other Etherscan custom chains configurations as long as 
      // they do not overwrite the "cronos" and "cronosTestnet" network
      {
        network: "cronos",
        chainId: 25,
        urls: {
          apiURL: "https://api.cronoscan.com/api",
          browserURL: "https://cronoscan.com/",
        },
      },
      {
        network: "cronosTestnet",
        chainId: 338,
        urls: {
          apiURL: "https://cronos.org/explorer/testnet3/api",
          browserURL: "https://cronos.org/explorer/testnet3/",
        },
      }
  }
};

export default config;

License

This project is licensed under Apache 2.0.