Transactions and Instructions

explain transactions and instructions

Transactions

message/signature
atomic transaction execution, size limit

Instructions

explain components of instruction
programid, accounts, instruction data

How to Transfer SOL

simple SOL transfer
final code

https://beta.solpg.io/656a0ea7fb53fa325bfd0c3e

Solana Playground

open solana playground
starter code

client.ts

import {
  LAMPORTS_PER_SOL,
  SystemProgram,
  Transaction,
  sendAndConfirmTransaction,
  Keypair,
} from "@solana/web3.js";
 
const connection = pg.connection;
 
const sender = pg.wallet.keypair;
const receiver = new Keypair();

Build Transfer Instruction

client.ts

const transferAmount = 0.01;
 
const transferInstruction = SystemProgram.transfer({
  fromPubkey: sender.publicKey,
  toPubkey: receiver.publicKey,
  lamports: transferAmount * LAMPORTS_PER_SOL,
});

Add Instruction to Transaction

client.ts

const transaction = new Transaction().add(transferInstruction);

Send Transaction

client.ts

const transactionSignature = await sendAndConfirmTransaction(
  connection,
  transaction,
  [sender],
);

Run script

Terminal

run

Source Code - Transfer Instruction

How to Create an Account

Source Code - Create Account Instruction

Minimum Rent

example transfer below minimum rent, tx fails

client.ts

const transferInstruction = SystemProgram.transfer({
  fromPubkey: sender.publicKey,
  toPubkey: receiver.publicKey,
  lamports: 1, // 1 lamport
});

Output

Running client...
  client.ts:
    Uncaught error: failed to send transaction: Transaction simulation failed: Transaction results in an account (1) with insufficient funds for rent

minimum lamports for accountinfo, where data field stores 0 bytes of extra data

client.ts

// Minimum balance for rent exemption for new account
const minumumLamports = await connection.getMinimumBalanceForRentExemption(0);
 
const transferInstruction = SystemProgram.transfer({
  fromPubkey: sender.publicKey,
  toPubkey: receiver.publicKey,
  lamports: minumumLamports,
});

Notes

explain wallet is just system account
transfer sol, both using helper and manually built instruction

Solana Account Model Tokens