Solana: MEV protection with Jito

import {
  Connection,
  Keypair,
  PublicKey,
  SystemProgram,
  TransactionMessage,
  VersionedTransaction,
  TransactionInstruction,
  LAMPORTS_PER_SOL,
} from "@solana/web3.js";
import bs58 from "bs58";
import "dotenv/config";

// Use your Chainstack endpoint for reads
const connection = new Connection(process.env.SOLANA_RPC!);
const payer = Keypair.fromSecretKey(bs58.decode(process.env.PRIVATE_KEY!));

// Jito block engine for sends
const JITO_ENDPOINT =
  "https://mainnet.block-engine.jito.wtf/api/v1/transactions";

// Any valid pubkey starting with "jitodontfront". Does not need to exist on-chain.
const DONT_FRONT = new PublicKey(
  "jitodontfront111111111111111111111111111111"
);

// Jito tip accounts — pick one at random to reduce contention
const TIP_ACCOUNTS = [
  "96gYZGLnJYVFmbjzopPSU6QiEV5fGqZNyN9nmNhvrZU5",
  "HFqU5x63VTqvQss8hp11i4wVV8bD44PvwucfZ2bU7gRe",
  "Cw8CFyM9FkoMi7K7Crf6HNQqf4uEMzpKw6QNghXLvLkY",
  "ADaUMid9yfUytqMBgopwjb2DTLSokTSzL1zt6iGPaS49",
  "DfXygSm4jCyNCybVYYK6DwvWqjKee8pbDmJGcLWNDXjh",
  "ADuUkR4vqLUMWXxW9gh6D6L8pMSawimctcNZ5pGwDcEt",
  "DttWaMuVvTiduZRnguLF7jNxTgiMBZ1hyAumKUiL2KRL",
  "3AVi9Tg9Uo68tJfuvoKvqKNWKkC5wPdSSdeBnizKZ6jT",
];

function addDontFront(instruction: TransactionInstruction): TransactionInstruction {
  return new TransactionInstruction({
    ...instruction,
    keys: [
      ...instruction.keys,
      { pubkey: DONT_FRONT, isSigner: false, isWritable: false },
    ],
  });
}

function randomTipAccount(): PublicKey {
  const idx = Math.floor(Math.random() * TIP_ACCOUNTS.length);
  return new PublicKey(TIP_ACCOUNTS[idx]);
}

async function sendWithMEVProtection() {
  const latestBlockhash = await connection.getLatestBlockhash();

  // Your actual instruction — add dontfront to it
  const transferIx = addDontFront(
    SystemProgram.transfer({
      fromPubkey: payer.publicKey,
      toPubkey: payer.publicKey,
      lamports: 0.001 * LAMPORTS_PER_SOL,
    })
  );

  // Jito tip — minimum 1000 lamports
  const tipIx = SystemProgram.transfer({
    fromPubkey: payer.publicKey,
    toPubkey: randomTipAccount(),
    lamports: 1000,
  });

  const message = new TransactionMessage({
    payerKey: payer.publicKey,
    recentBlockhash: latestBlockhash.blockhash,
    instructions: [transferIx, tipIx],
  }).compileToV0Message();

  const transaction = new VersionedTransaction(message);
  transaction.sign([payer]);

  // Send through Jito block engine, NOT standard RPC
  const serialized = Buffer.from(transaction.serialize()).toString("base64");
  const response = await fetch(JITO_ENDPOINT, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      jsonrpc: "2.0",
      id: 1,
      method: "sendTransaction",
      params: [serialized, { encoding: "base64" }],
    }),
  });

  const result = await response.json();
  console.log("Sent with dontfront protection:", result.result);
}

sendWithMEVProtection();