Support other explorer to verify smart contract with verify plugin

[huihzhao]

I am from opbnbscan explorer team and I`m doing the compatibility testing for our explorer API of hardhat. but seems the verify plugin only works with etherscan and blockscout. Just wondering how to support other explorers like ours.

[schaable]

Hi @huihzhao! It depends on your explorer API. If it has the same interface than the Etherscan API, you can add it as a custom chain like this:

// hardhat.config.ts

const config: HardhatUserConfig = {
  etherscan: {
    apiKey: {
      <explorer-name>: "<explorer-api-key>"
    },
    customChains: [
      {
        network: <explorer-name>,
        chainId: <explorer-chain-id>,
        urls: {
          apiURL: <explorer-api-url>,
          browserURL: <explorer-browser-url>
        }
      }
    ]
  }
}

However, if the interface is different, you would need to extend the plugin with your own subtasks. You can package it in your own plugin, for example hardhat-verify-bnb. Let me know if you want to go that route and we can discuss the details.

[huihzhao]

Thanks for the clarification, it seems our API is not fully compatible with the ethscan ones. That is to say we may want to add the subtask. May I know how to?

[huihzhao]

It is better that you can have a doc for this. I believe more chains will have similar requirements. 😄

[schaable]

To add a new verification provider, you would need to override the verify:get-verification-subtasks subtask and add your subtask to the pipeline. You can find the definition here. Please note that there's an open PR that may change the code structure slightly, although it should not affect this process.

For example:

subtask("verify:get-verification-subtasks", async (taskArgs, hre, runSuper) => {
  const verificationSubtasks = await runSuper(taskArgs);

  verificationSubtasks.push("verify:opbnbscan");

  return verificationSubtasks;
});

Then, you would need to add the verify:opbnbscan subtask with your custom validation logic.

[schaable]

It is better that you can have a doc for this. I believe more chains will have similar requirements. 😄

I don't think it's necessary, considering there's already a document explaining how to override tasks. I agree that there should be a code example there, and I will work on adding it. If we encounter similar questions in the future, we can consider providing a tailored explanation.