How do I send transactions with new web3.js?

Question

I've been trying to create & send transactions like this, but I'm getting SolanaError: JSON-RPC error: Invalid method parameter(s) (invalid base58 encoding: InvalidCharacter { character: '+', index: 12 })

  const transactionMessage = pipe(
    createTransactionMessage({ version: 0 }),
    (tx) => setTransactionMessageFeePayerSigner(kp, tx),
    (tx) =>
      setTransactionMessageLifetimeUsingBlockhash(
        { blockhash, lastValidBlockHeight },
        tx
      ),
    (tx) => appendTransactionMessageInstructions(instructions, tx),
    (m) => addSignersToTransactionMessage([kp, newAccountKp], m)
  );

  const tx = await pipe(compileTransaction(transactionMessage), (tx) =>
    signTransaction([kp.keyPair, newAccountKp.keyPair], tx)
  );

  const sig = rpc
    .sendTransaction(getBase64EncodedWireTransaction(tx), {
      skipPreflight: true,
    })
    .send();

Answer 1

The sendTransaction JSON-RPC method defaults to a base58 encoding: https://solana.com/docs/rpc/http/sendtransaction#parameters

You need to pass base64 encoding to override that:

  const sig = rpc
    .sendTransaction(getBase64EncodedWireTransaction(tx), {
      encoding: 'base64',
      skipPreflight: true,
    })
    .send();

Note that there is a simpler API that takes care of this for you: sendTransactionWithoutConfirmingFactory

const sendTransaction = sendTransactionWithoutConfirmingFactory({ rpc });
await sendTransaction(tx, { skipPreflight: true })

There is also sendAndConfirmTransactionFactory if you'd like to also use subscriptions to confirm the transaction has landed before continuing.

Answer 2

Found a solution. Turns out I needed to create sendAndConfirm via sendAndConfirmTransactionFactory.

const rpc = createSolanaRpc('http://127.0.0.1:8899');
const rpcSubscriptions = createSolanaRpcSubscriptions('ws://127.0.0.1:8900');
const sendAndConfirm = sendAndConfirmTransactionFactory({ rpc, rpcSubscriptions });

const { value: latestBlockhash } = await rpc.getLatestBlockhash().send();
const message = pipe(
  createTransactionMessage({ version: 0 }),
  (m) => setTransactionMessageFeePayerSigner(feePayer, m),
  (m) => setTransactionMessageLifetimeUsingBlockhash(latestBlockhash, m),
  (m) => appendTransactionMessageInstructions(instructions, m),
);

const signedTransaction = await signTransactionMessageWithSigners(message);

// Optional, to look up tx on explorers
const signature = getSignatureFromTransaction(signedTransaction);

await sendAndConfirm(signedTransaction, { commitment });