truffle-plugin-verify

This truffle plugin allows you to automatically verify your smart contracts' source code on Etherscan, straight from the Truffle CLI.

I wrote a tutorial on my website that goes through the entire process of installing and using this plugin: Automatically verify Truffle smart contracts on Etherscan.

Installation

1. Install the plugin with npm

   npm install truffle-plugin-verify
2. Add the plugin to your truffle.js or truffle-config.js file

   module.exports = {
     /* ... rest of truffle-config */
   
     plugins: [
       'truffle-plugin-verify'
     ]
   }
3. Generate an API Key on your Etherscan account (see the Etherscan website)
4. Add your Etherscan API key to your truffle config (make sure to use something like dotenv so you don't commit the api key)

   module.exports = {
     /* ... rest of truffle-config */
   
     api_keys: {
       etherscan: 'MY_API_KEY'
     }
   }

Usage

Before running verification, make sure that you have actually deployed your contracts to a public network with Truffle. After deployment, run the following command with one or more contracts that you wish to verify:

truffle run verify SomeContractName AnotherContractName --network networkName [--debug]

The network parameter should correspond to a network defined in the Truffle config file, with the correct network id set. The Ethereum mainnet and all main public testnets are supported.

For example, if we defined rinkeby as network in Truffle, and we wish to verify the SimpleStorage contract:

truffle run verify SimpleStorage --network rinkeby

This can take some time, and will eventually either return Pass - Verified or Fail - Unable to verify for each contract. Since the information we get from the Etherscan API is quite limited, it is currently impossible to retrieve any more information on verification failure. There should be no reason though why the verification should fail if the usage is followed correctly.

If you do receive a Fail - Unable to verify and you are sure that you followed the instructions correctly, please open an issue and I will look into it. Optionally, a --debug flag can also be passed into the CLI to output additional debug messages. It is helpful if you run this once before opening an issue and providing the output in your bug report.

Address override (Optional)

You can optionally provide an explicit address of the contract(s) that you wish to verify. This may be useful when you have deployed multiple instances of the same contract. The address is appended with @<address> as follows:

truffle run verify SimpleStorage@0x61C9157A9EfCaf6022243fA65Ef4666ECc9FD3D7 --network rinkeby

Adding Preamble (Optional)

You can optionally provide a preamble to the beginning of your verified source code. This may be useful for adding authorship information, links to source code, copyright information, or versioning information.

To do so, add the following to your truffle.js or truffle-config.js file

module.exports = {
  /* ... rest of truffle-config */

  verify: {
    preamble: "Author: John Citizen.\nVersion: 1.0.1"
  }
}

Debugging

You can pass an optional --debug flag into the plugin to display debug messages during the verification process. This is generally not necessary, but can be used to provide additional information when the plugin appears to malfunction.

truffle run verify SimpleStorage --network rinkeby

Notes

This plugin gets compiler optimisation settings from the truffle config file, so make sure that your truffle config settings are the same as they were when your contracts were compiled.

This plugin has a naming conflict with the truffle-security plugin, so when using both truffle-security and truffle-plugin-verify in the same project, truffle run etherscan can be used instead of truffle run verify for truffle-plugin-verify.

Donations

If you've used this plugin and found it helpful in your workflow, please consider sending some Ξ or tokens to 0xe126b3E5d052f1F575828f61fEBA4f4f2603652a.