PolkadotJS ALICE address differs

Question

When I try to derive the Alice account with PolkadotJS I somehow end up with a different address than in the docs.

Here is the code:

const keyring = new (require('@polkadot/keyring').Keyring)();

let pair = keyring.createFromUri('//Alice');
console.log(`${pair.address}`);
// prints 5FA9nQDVg267DEd8m1ZypXLBnvN7SFxYwV7ndqSYGiN9TTpu

Prefixing the it with the dev menmonic bottom drive obey lake curtain smoke basket hold race lonely fit walk does not make a difference.

The unofficial python bindings from polkascan and subkey both yield the correct address:

from substrateinterface import Keypair

keypair = Keypair.create_from_uri('//Alice')
print(keypair.ss58_address)
# prints 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY

Subkey:

docker run -it --rm --pull=always docker.io/parity/subkey:latest inspect "//Alice" | grep "SS58 Address"
# prints 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY

Am I somehow using it wrong or why is PolkadotJS printing 5FA9nQDVg267DEd8m1ZypXLBnvN7SFxYwV7ndqSYGiN9TTpu?

Answer 1

Make sure you specify your keyring to use sr25519 versus ed25519 which I believe is default:

// Create a keyring instance
const keyring = new Keyring({ type: 'sr25519' });

See this complete example:

// Import the API, Keyring and some utility functions
const { ApiPromise } = require('@polkadot/api');
const { Keyring } = require('@polkadot/keyring');

async function main () {
  // Instantiate the API
  const api = await ApiPromise.create();

  // Constuct the keyring after the API (crypto has an async init)
  const keyring = new Keyring({ type: 'sr25519' });

  // Add Alice to our keyring with a hard-deived path (empty phrase, so uses dev)
  const alice = keyring.addFromUri('//Alice');

  console.log(`${alice.address}`);
  // prints 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY

}

main().catch(console.error).finally(() => process.exit());