import {

Connection,

Keypair,

PublicKey,

SystemProgram,

Transaction,

ComputeBudgetProgram,

} from "@solana/web3.js";

import bs58 from "bs58";

import fetch from "node-fetch";

// 1) Build & sign locally using YOUR or PUBLIC RPC

const RPC_URL = process.env.SOLANA_RPC_URL || "https://api.mainnet-beta.solana.com";

const payer = Keypair.fromSecretKey(bs58.decode(process.env.SECRET_KEY)); // base58-encoded 64-byte secret key

const connection = new Connection(RPC_URL, "confirmed");

const recipient = new PublicKey("ReplaceWithRecipientPubkey");

// priority fee (micro-lamports per compute unit). Tune to network conditions.

const MICRO_LAMPORTS_PER_CU = 1_000;

const { blockhash } = await connection.getLatestBlockhash("finalized");

const tx = new Transaction({ recentBlockhash: blockhash, feePayer: payer.publicKey });

// Add compute budget for priority fees (optional)

tx.add(ComputeBudgetProgram.setComputeUnitPrice({ microLamports: MICRO_LAMPORTS_PER_CU }));

// Your core instruction(s)

tx.add(SystemProgram.transfer({

fromPubkey: payer.publicKey,

toPubkey: recipient,

lamports: 1_000, // example

}));

// OPTIONAL: add your own Jito tip instruction (transfer to the Jito tip account) before signing

// tx.add(SystemProgram.transfer({ fromPubkey: payer.publicKey, toPubkey: JITO_TIP_ACCOUNT, lamports: YOUR_TIP }));

tx.sign(payer);

const base64Tx = tx.serialize().toString("base64");

// 2) Send via TxEngine Sender

const host = process.env.TXENGINE_HOST; // from Telegram bot

const token = process.env.TXENGINE_TOKEN; // from Telegram bot

const jitoQS = process.env.JITO ==="1" ? "&jito=1" : "";

const url = `https://${host}/v0/transactions?token=${token}${jitoQS}`;

const res = await fetch(url, {

method: "POST",

headers: { "Content-Type": "application/json" },

body: JSON.stringify({ transactions: [base64Tx] }),

});

if (!res.ok) throw new Error(await res.text());

console.log("TxEngine response:", await res.json());