How to send a short message / memo to a specific address

Question

Hello Solana lovers / buidlers,

I would love to send short message to Solana users to their address. For example by sending a transaction on the block chain. Is there a simple way to do this ?

I found a message application using jabber from bonfida, but it's way too expensive and complicated for what I want to do. I found a memo program but there are no simple example of how to use it in JavaScript and / or React

Thanks a lot in advance for your help 😊

Answer 1

You can add messages to transactions using the memo program.

Here's an example of sending "Data to send in transaction" in Javascript:

import {
  Connection,
  Keypair,
  SystemProgram,
  LAMPORTS_PER_SOL,
  PublicKey,
  Transaction,
  TransactionInstruction,
  sendAndConfirmTransaction,
} from "@solana/web3.js";

(async () => {
  const fromKeypair = Keypair.generate();
  const toKeypair = Keypair.generate();

  const connection = new Connection(
    "https://api.devnet.solana.com",
    "confirmed"
  );

  const airdropSignature = await connection.requestAirdrop(
    fromKeypair.publicKey,
    LAMPORTS_PER_SOL
  );

  await connection.confirmTransaction(airdropSignature);

  const lamportsToSend = 10;

  const transferTransaction = new Transaction().add(
    SystemProgram.transfer({
      fromPubkey: fromKeypair.publicKey,
      toPubkey: toKeypair.publicKey,
      lamports: lamportsToSend,
    })
  );

  await transferTransaction.add(
    new TransactionInstruction({
      keys: [
        { pubkey: fromKeypair.publicKey, isSigner: true, isWritable: true },
      ],
      data: Buffer.from("Data to send in transaction", "utf-8"),
      programId: new PublicKey("MemoSq4gqABAXKb96qnH8TysNcWxMyWCqXgDLGmfcHr"),
    })
  );

  await sendAndConfirmTransaction(connection, transferTransaction, [
    fromKeypair,
  ]);
})();