TypeScript

Use full service RPC for fetching latest blockhash.

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

const NOZOMI_ENDPOINT = "https://nozomi.temporal.xyz/api/sendTransaction2?c=<YOUR_API_KEY>";
const NOZOMI_TIP = new PublicKey("TEMPaMeCRFAS9EKF53Jd6KpHxgL47uWLcpFArU1Fanq");
const MIN_TIP_AMOUNT = 1_000_000;

const SOLANA_RPC_ENDPOINT = "https://api.mainnet-beta.solana.com";

async function sendNozomiTxn(
    ixns: TransactionInstruction[],
    signer: Keypair,
    nozomiEndpoint: string,
    solanaRpcClient: Connection
): Promise<void> {
    const tipIxn = SystemProgram.transfer({
        fromPubkey: signer.publicKey,
        toPubkey: NOZOMI_TIP,
        lamports: MIN_TIP_AMOUNT
    });
    ixns.push(tipIxn);

    const { blockhash } = await solanaRpcClient.getLatestBlockhash();

    const messageV0 = new TransactionMessage({
        payerKey: signer.publicKey,
        recentBlockhash: blockhash,
        instructions: ixns,
    }).compileToV0Message();

    const versionedTxn = new VersionedTransaction(messageV0);
    versionedTxn.sign([signer]);

    const txnBytes = versionedTxn.serialize();
    const txnBase64 = Buffer.from(txnBytes).toString('base64');

    const response = await fetch(nozomiEndpoint, {
        method: 'POST',
        headers: {
            'Content-Type': 'text/plain',
        },
        body: txnBase64
    });

    if (!response.ok) {
        const errorText = await response.text();
        throw new Error(`Transaction failed with status ${response.status}: ${errorText}`);
    }

    // api v2 does not return a signature, just check for success
    console.log('Transaction sent successfully');
}

function buildIxns(): TransactionInstruction[] {
    // your instruction building logic here..
    return [];
}

async function main() {
    const solanaRpcClient = new Connection(SOLANA_RPC_ENDPOINT);

    // replace with actual keypair loading logic
    const signer = Keypair.generate();

    const ixns = buildIxns();

    await sendNozomiTxn(ixns, signer, NOZOMI_ENDPOINT, solanaRpcClient);
}

main().catch(err => {
    console.error(err);
});