Quick Start

Start landing transactions faster with BlockSprint.

What You'll Need

Before you begin, make sure you have:

• A BlockSprint account — Sign up at https://blocksprint.io
• An API key — Created automatically when you register
• A signed Solana transaction — Legacy, v0 or Transaction V1, ready to submit

INFO

New accounts get 50 TPS by default. Need more? Reach out on https://t.me/blocksprint.

Step 1: Grab Your API Key

After signing up, head to Api Keys page. Your first key is generated automatically — it starts with bs_.

Step 2: Pick Your Endpoint

BlockSprint runs nodes across the globe. Choose the one closest to your servers: Endpoints

Step 3: Include a Tip

Every transaction must include a tip. Add a SOL transfer of at least 0.001 SOL to one of the BlockSprint tip wallets:

import { SystemProgram, PublicKey, LAMPORTS_PER_SOL } from "@solana/web3.js";

// BlockSprint tip wallets - rotate to avoid write lock contention
const TIP_WALLETS = [
  "Sp1x2AqpQckPLaWnWCJUNg8k6qQexfaEWcSRKf5JcDV",
  "Sp4JHSh9cksfzXbgK7Pq2ovtn8LirLQydaJKTsiNT77",
  "Sp1xMS2cbw83SZDNr4AGqkBYYLjb3LvVnmDSrTMaHkr",
  "SpagSJmnh8E9cGT5Y431xPPaS2c1xLREGGCWN9yDeUf",
  "SpWrza9E63MQuHeGnnfzmtLVCs3pBdjyKPXUABPo9nq",
  "SpXyoqMHJEhsNQ9fHh3DTGGzrGroZ5zfDtJwFvN4kXi",
  "Spv2g3L837bVeHwkyb18LhA5P1bvJbkvaZbxcZXbwC2",
  "SpDUe5MyFGG97SmdBQMWNPbx2Et9bZt2TCbZm3TujgX",
  "SpKZ28tFzQ13kVjHhsyDEiQfkPGjA7Wmk185KcEDyuh",
  "SpxPqegfoR3QkBN7guRUiU6QfhtTW1CnKSTSSapumqm",
];


const tipWallet = TIP_WALLETS[Math.floor(Math.random() * TIP_WALLETS.length)];

// Add tip instruction to your transaction
transaction.add(
  SystemProgram.transfer({
    fromPubkey: yourWallet.publicKey,
    toPubkey: new PublicKey(tipWallet),
    lamports: 0.001 * LAMPORTS_PER_SOL, // minimum tip: 0.001 SOL
  })
);

INFO

See the Tipping Guide: https://docs.blocksprint.io/general/tipping-and-rate-limits for details.

Step 4: Send It

UDP (recommended). The fastest way to send: one datagram with your API key and the signed transaction wire bytes, no handshake. See UDP for the packet layout, all endpoints and full examples.

import dgram from "node:dgram";

const apiKey = Buffer.from("YOUR_API_KEY");
// txBytes = your signed transaction as raw wire bytes (Buffer)
const packet = Buffer.concat([Buffer.from([apiKey.length]), apiKey, txBytes]);

const socket = dgram.createSocket("udp4"); // create once, reuse for every send
socket.send(packet, 5000, "fra.blocksprint.io");

let api_key = "YOUR_API_KEY";
// tx_bytes = your signed transaction as raw wire bytes
let mut packet = vec![api_key.len() as u8];
packet.extend_from_slice(api_key.as_bytes());
packet.extend_from_slice(&tx_bytes);

let socket = std::net::UdpSocket::bind("0.0.0.0:0")?; // create once, reuse for every send
socket.send_to(&packet, "fra.blocksprint.io:5000")?;

sendTransaction (HTTP). Also supported, but the slowest option. Use it only if you need an HTTP response; otherwise use UDP. Pass your API key as a query parameter and POST your signed transaction.

cURL

curl 'https://fra.blocksprint.io?api_key=YOUR_API_KEY' \
  -X POST \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "sendTransaction",
    "params": ["YOUR_BASE64_TRANSACTION", {"encoding": "base64", "skipPreflight": true}]
  }'

JavaScript

const endpoint = "https://fra.blocksprint.io";
const apiKey = "YOUR_API_KEY";

const result = await fetch(`${endpoint}?api_key=${apiKey}`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    jsonrpc: "2.0",
    id: 1,
    method: "sendTransaction",
    params: [base64Tx, { encoding: "base64", skipPreflight: true }],
  }),
});

const { result: txSignature } = await result.json();

Rust

let endpoint = format!("https://fra.blocksprint.io?api_key={}", api_key);

let res = reqwest::Client::new()
    .post(&endpoint)
    .json(&serde_json::json!({
        "jsonrpc": "2.0",
        "id": 1,
        "method": "sendTransaction",
        "params": [base64_tx, {"encoding": "base64", "skipPreflight": true}]
    }))
    .send()
    .await?;

Handling Errors

Code	What It Means	What To Do
200	Accepted	Transaction is being forwarded
400	Invalid transaction, encoding or tip	Fix the transaction and its tip
401	Bad API key	Double-check your key
403	Key expired, or IP not allowed for this key	Check the key in your dashboard
5xx	Server issue	Retry with exponential backoff

Retry pattern:

async function sendWithRetry(tx, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    const res = await sendTransaction(tx);
    if (res.status < 500) return res;

    await new Promise(r => setTimeout(r, Math.pow(2, i) * 1000));
  }
  throw new Error("Max retries exceeded");
}

To land a transaction, rebroadcast the same signed transaction every ~2 seconds until it confirms or its blockhash expires.