How to get private key from hardhat ethers signer?

Question

In hardhat I'd like to get the privateKey from a signer, the privateKeys are initialised in the hardhat.config networks.network.accounts.

import { ethers } from "hardhat";
import { Signer } from "ethers";

const accounts = await ethers.getSigners();
const account0: Signer = accounts[0];

I don't see any attribute/method on the Signer instance to get the privateKey.

Answer 1

You can get the private keys from the network config (localhost, mainnet, etc):

import { config } from "hardhat";

console.log('Accounts from config:', config.networks.mainnet.accounts);

In case you want to get the private keys for hardhat accounts:

const accounts = config.networks.hardhat.accounts;
const index = 0; // first wallet, increment for next wallets
const wallet1 = ethers.Wallet.fromMnemonic(accounts.mnemonic, accounts.path + `/${index}`);

const privateKey1 = wallet1.privateKey
...

Here is an example, how I use this:

https://github.com/0xweb-org/dequanto/blob/8bab2114875b055f5f6ea361951d0d7083f3259c/src/hardhat/HardhatProvider.ts#L41

Answer 2

Well, think on connecting ether.js with some wallet. The private key wouldn’t be passed to the library because than it could be stolen. The library issues a request to the wallet to sign the transaction.

So the private key isn’t stored inside Signer.