JS

This page describes how to build and send Solana transactions using JS

Solana's transaction sending service is no longer bound to the subscription plan, with rate limit default to 3 TPS. API key could be required from Authentication. If you need to increase the TPS limit, please contact us and we will handle it as soon as possible.

Code example

Request Example

HTTP

const axios = require('axios');
const web3 = require('@solana/web3.js');
const bs58 = require('bs58');

// ------------------ Configuration Constants ------------------
// BlockRazor relay endpoint address
const httpEndpoint = "http://frankfurt.solana.blockrazor.xyz:443/sendTransaction";
const healthEndpoint = "http://frankfurt.solana.blockrazor.xyz:443/health";
// Replace with your Solana RPC endpoint
const mainNetRPC = "";
// Replace with your authKey
const authKey = "";
// Replace with your private key (base58)
const privateKey = "";
// Replace with your target public key
const publicKey = "";
// Send mode
const mode = "fast";
// Safe window
const safeWindow = 5; // only take effect in sandwichMitigation mod
// Revert protection
const revertProtection = false;
// Transaction amount
const amount = 200_000;
// Tip amount
const tipAmount = 100_000;

const tipAccounts = [
    "Gywj98ophM7GmkDdaWs4isqZnDdFCW7B46TXmKfvyqSm",
    "FjmZZrFvhnqqb9ThCuMVnENaM3JGVuGWNyCAxRJcFpg9",
    "6No2i3aawzHsjtThw81iq1EXPJN6rh8eSJCLaYZfKDTG",
    "A9cWowVAiHe9pJfKAj3TJiN9VpbzMUq6E4kEvf5mUT22",
    "68Pwb4jS7eZATjDfhmTXgRJjCiZmw1L7Huy4HNpnxJ3o",
    "4ABhJh5rZPjv63RBJBuyWzBK3g9gWMUQdTZP2kiW31V9",
    "B2M4NG5eyZp5SBQrSdtemzk5TqVuaWGQnowGaCBt8GyM",
    "5jA59cXMKQqZAVdtopv8q3yyw9SYfiE3vUCbt7p8MfVf",
    "5YktoWygr1Bp9wiS1xtMtUki1PeYuuzuCF98tqwYxf61",
    "295Avbam4qGShBYK7E9H5Ldew4B3WyJGmgmXfiWdeeyV",
    "EDi4rSy2LZgKJX74mbLTFk4mxoTgT6F7HxxzG2HBAFyK",
    "BnGKHAC386n4Qmv9xtpBVbRaUTKixjBe3oagkPFKtoy6",
    "Dd7K2Fp7AtoN8xCghKDRmyqr5U169t48Tw5fEd3wT9mq",
    "AP6qExwrbRgBAVaehg4b5xHENX815sMabtBzUzVB4v8S",
];

// ------------------ Axios HTTP Client (Connection Reuse Enabled) ------------------
const httpClient = axios.create({
    timeout: 10000,
    headers: {
        'Content-Type': 'application/json',
        'apikey': authKey,
    },
    httpAgent: new (require('http').Agent)({ keepAlive: true }),
    httpsAgent: new (require('https').Agent)({ keepAlive: true }),
});

// ------------------ Periodic Health Ping to Keep Connection Alive ------------------
async function pingHealth() {
    try {
        const res = await httpClient.get(healthEndpoint);
        console.log(`Health result:`, res.data);
    } catch (err) {
        console.error('Health check failed:', err.message);
    }
}

// ------------------ Build and Send Transaction ------------------
async function sendTx() {
    const senderPrivateKey = new Uint8Array(bs58.decode(privateKey));
    const senderKeypair = web3.Keypair.fromSecretKey(senderPrivateKey);
    const receiver = new web3.PublicKey(publicKey);
    const tipAccount = new web3.PublicKey(tipAccounts[Math.floor(Math.random() * tipAccounts.length)]);

    const connection = new web3.Connection(mainNetRPC);
    const { blockhash } = await connection.getLatestBlockhash('finalized');

    const tx = new web3.Transaction()
        .add(web3.SystemProgram.transfer({
            fromPubkey: senderKeypair.publicKey,
            toPubkey: tipAccount,
            lamports: tipAmount,
        }))
        .add(web3.SystemProgram.transfer({
            fromPubkey: senderKeypair.publicKey,
            toPubkey: receiver,
            lamports: amount,
        }));

    tx.recentBlockhash = blockhash;
    tx.feePayer = senderKeypair.publicKey;
    tx.sign(senderKeypair);

    const serialized = tx.serialize();
    const base64Tx = serialized.toString('base64');

    const payload = {
        transaction: base64Tx,
        mode: mode,
        safeWindow: safeWindow,
		RevertProtection: revertProtection,
    };

    try {
        const res = await httpClient.post(httpEndpoint, payload);
        console.log('[send tx] response:', res.data);
    } catch (err) {
        console.error('SendTx failed:', err.response?.data || err.message);
    }
}

// ------------------ Main Entry ------------------
(async () => {
    // Initial health check (establish connection)
    await pingHealth();

    // Periodically send /health to keep connection alive
    setInterval(pingHealth, 30 * 1000);
    sendTx().catch(console.error);
})();

gRPC

Proto