How do I connect to a wallet by mnemonic via JavaScript? (to get account balance, for instance)

Question

I've successfully created all the account "bits" from mnemonic (generated here for tests):

const monerojs = require("monero-javascript");

const mnemonic = ...
const moneroNetwork = monerojs.MoneroNetworkType.TESTNET;
// in async func
    const wallet = await monerojs.createWalletKeys({
        networkType: moneroNetwork,
        mnemonic
    });
    const keys = {
        privateSpend: await wallet.getPrivateSpendKey(),
        privateView: await wallet.getPrivateViewKey(),
        publicSpend: await wallet.getPublicSpendKey(),
        publicView: await wallet.getPublicViewKey(),
    }
    const address = await wallet.getPrimaryAddress();

and send some funds to the address via the faucet.

Now I'm trying to connect to the test account via a public node (one from here, should be ok for testing) and I'm stuck. To give a more complete idea, I'm trying to get the balance of the account for which I have creds.

monero-javascript looks like a right tool for that, but I don't get it: here are my attempts based on the docs:

// attempt 1, RPC wallet
const nodeUrl = ... // taken from https://monero.fail for quick dev, worked for getBlockCount RPC (see https://monero.stackexchange.com/a/13549/14510)
const walletRpc = await monerojs.connectToWalletRpc(nodeUrl);
await walletRpc.createWallet({ // *
    // networkType: moneroNetwork,
    mnemonic,
});
// failes with Method not found (at line *) despite it's almost literally an example from docs

// attempt 2, adapted from the other example
const walletFull = await monerojs.createWalletFull({
    networkType: moneroNetwork,
    mnemonic,
    // server: connection
    serverUri: nodeUrl
})
// call fails with "The URL must be of scheme file"

// attempt 3, based on https://github.com/monero-ecosystem/monero-javascript/blob/master/docs/developer_guide/connection_manager.md
const connectionManager = new monerojs.MoneroConnectionManager();
const connection = new monerojs.MoneroRpcConnection(nodeUrl);
connectionManager.setConnection(connection);
await connectionManager.checkConnection();
console.log("Connection manager is connected: " + connectionManager.isConnected());
console.log("Connection is online: " + connectionManager.getConnection().isOnline());
console.log("Connection is authenticated: " + connectionManager.getConnection().isAuthenticated());
/* logs 
Connection manager is connected: true
Connection is online: true
Connection is authenticated: true
   but.. now what? How to get things from wallet?

   I've also tried to create wallet like above after established connection and tried

       const transfers = await wallet.getTransfers();

   but it fails with "Not supported" (like when without connection)
*/

Another libs also don't seem to make an attempt to cover this case in their docs, for instance monero-nodejs starts with create_wallet (generates mnemonic) and doesn't provide examples about "recovering" wallet from mnemonic.

Does anyone know how to connect to a wallet by a given mnemonic? Or at least how to get an account balance by mnemonic?

(deterministic style is implied, private view key is supposed to be derived from private spend key)

Answer 1

Does anyone know how to connect to a wallet by a given mnemonic? Or at least how to get an account balance by mnemonic?

Your mnemonic words are for restoring a wallet. Not for interacting (such as querying balance) with your wallet.

const nodeUrl = ... // taken from https://monero.fail for quick dev, worked for getBlockCount RPC (see https://monero.stackexchange.com/a/13549/14510)
const walletRpc = await monerojs.connectToWalletRpc(nodeUrl);

connectToWalletRpc(...) connects to an instance of monero-wallet-rpc, not an instance of monerod. Public nodes (as listed on https://monero.fail) are instances of monerod, not wallets.