Aptos

Load it

import { useBlockchain, blockchains } from "@agntn/keys";

const aptosChain = useBlockchain(await blockchains.aptos()());

The address

Public key, then one scheme byte 0x00 for a single ed25519 signer, then SHA3-256. The 32 byte digest with 0x in front is the address.

const publicKey = aptosChain.getKeyPublic(privateKey);
aptosChain.getAddress(publicKey); // 0x7e08ac7940568c91564ddc6f5f3bf91b15a9334194ab7855daeac51c5cc74936

The scheme byte is the part people forget when they reimplement this by hand. Hash the bare key and you get a valid looking address that belongs to nobody.

Validation

aptosChain.validateAddress("0x7e08ac7940568c91564ddc6f5f3bf91b15a9334194ab7855daeac51c5cc74936"); // true
aptosChain.validateAddress("0x1"); // true, special address
aptosChain.validateAddress("7e08ac7940568c91564ddc6f5f3bf91b15a9334194ab7855daeac51c5cc74936"); // false, no 0x

0x plus 64 hex characters, case doesn't matter. The single digit forms like 0x1 are the framework addresses and validate as well. There's no checksum, so a wrong character produces a different valid address instead of an error. Copy carefully.

Mnemonics

SLIP-10, hardened segments only:

aptosChain.deriveHDWallet(mnemonic, "m/44'/637'/0'/0'/0'").address;

That is the path Petra uses for the first account.

Signing

Plain ed25519 over the message bytes, hex out. verifyMessage checks it against the public key.