How to get implementation address after deployProxy()? (@open-zepplin/hardhat-upgrades)

Question

I'm deploying my token using the proxy pattern via hardhat-upgrades.

const TokenFactory = await ethers.getContractFactory('MyToken');
const token = await upgrades.deployProxy(TokenFactory);

const result = await token.deployed();

Next I want to verify the contract on etherscan using hardhat-etherscan

await run('verify:verify', {
   address: token.address,
   constructorArguments: []
});

The problem is token.address points to the proxy. From what I understand the proxy doesnt need to be verified, but rather the implementation does.

But I can't seem to find a way to get the implementation address.

Where is this elusive address and how can I access it programmatically after deploying the proxy?

Answer 1

Try the below,

import { getImplementationAddress } from '@openzeppelin/upgrades-core';
    
const currentImplAddress = await getImplementationAddress(provider, proxyAddress);

Answer 2

You can also use the hardhat upgrades plugin for the same effect as the accepted answer:

import { ethers, upgrades } from "hardhat";

const currentImplAddress = await upgrades.erc1967.getImplementationAddress(proxyAddress);