ethers.js - How to derive child addresses + private keys from HD private key

Question

I have a HD private key which I have derived from my mnemonic using the ethers library. I would now like to derive child addresses and corresponding private keys from it.

Does anybody know how I can do this?

This is how I have obtained the HD private key:

const xKey = ethers.Wallet.fromMnemonic(...)

Thanks in advance!

Answer 1

ethers.Wallet.fromMnemonic is used to create the master private key out of they mnemonic, but for creating new pairs of public and private keys I think you should use this method with different passphrase for each pair:

const HDNode  = await ethers.utils.HDNode.fromMnemonic(YOUR_MNEMONIC, null, YOUR_PASSPHRASE);

When you check the new generated HDNode inside of it you can see it contains the same mnenomic you used for the master private key.

Answer 2

const derived = xKey.derivePath("m/44'/60'/0'/0/0");

You should use the derivePath function of the master key, specifying the path of the derived keys.

See more bip-32 and hdnode.