Land your Solana transactions in the same block.

# BASE64_SIGNED_TX: your signed transaction, with the tip transfer inside it.
curl -X POST https://fra.relay.allenhark.com/v1/sendTx \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{"tx":"BASE64_SIGNED_TX","simulate":false}'

# → {"status":"accepted","request_id":"550e8400-…","signature":"5wH…"}

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

const RELAY = "https://fra.relay.allenhark.com/v1/sendTx";
const TIP_LAMPORTS = 1_000_000; // 0.001 SOL minimum; raise it under congestion
const TIP_WALLETS = [
  "hark1zxc5Rz3K8Kquz79WPWFEgNCFeJnsMJ16f22uNP",
  "harkm2BTWxZuszoNpZnfe84jRbQTg6KGHaQBmWzDGQQ",
  "hark4CwtTnN2y9FaxjcFBAJdJqQrpouu5pgEixfqdEz",
  "harkoJfnM6dxrJydx5eVmDVwAgwC94KbhuxF69UbXwP",
  "hark6hUDUTekc1DGxWdJcuyDZwf6pJdCxd4SXAVtta6",
  "harkoTvFpKSrEQduYrNHXCurARVT19Ud3BnFhVxabos",
  "harkEpXoJv5qVzHaN7HSuUAd6PHjyMcFMcDYBMDJCEQ",
  "harkyXDdZSoJGyCxa24t2QXx1poPyp8YfghbtpzGSzK",
  "harkR2YJ4Dpt4UDJTcBirjnSPBhNpQFcoFkNpCkVqNk",
  "harkRBygM8pHYe4K8eBjfxyEX19oJn3LepFjvNbLbyi",
  "harkYFxB6DuUFNwDLvA5CQ66KpfRvFgUoVypMagNcmd",
];

export async function sendViaRelay(
  connection: Connection,
  payer: Keypair,
  instructions: TransactionInstruction[],
): Promise<string> {
  const tipWallet = new PublicKey(TIP_WALLETS[Math.floor(Math.random() * TIP_WALLETS.length)]);
  const tx = new Transaction().add(
    ...instructions,
    // The tip: a top-level transfer to a random tip wallet.
    SystemProgram.transfer({ fromPubkey: payer.publicKey, toPubkey: tipWallet, lamports: TIP_LAMPORTS }),
  );
  tx.feePayer = payer.publicKey;
  tx.recentBlockhash = (await connection.getLatestBlockhash("confirmed")).blockhash;
  tx.sign(payer);

  const res = await fetch(RELAY, {
    method: "POST",
    headers: { "Content-Type": "application/json", "x-api-key": "YOUR_API_KEY" },
    body: JSON.stringify({ tx: tx.serialize().toString("base64"), simulate: false }),
  });
  const result = await res.json();
  if (result.status !== "accepted") throw new Error(`Relay rejected: ${result.code ?? result.error}`);
  return result.signature; // accepted is not landed: confirm it on chain
}

use base64::{engine::general_purpose::STANDARD, Engine};
use rand::seq::SliceRandom;
use solana_client::nonblocking::rpc_client::RpcClient;
use solana_sdk::{
    instruction::Instruction, pubkey::Pubkey, signature::{Keypair, Signer},
    system_instruction, transaction::Transaction,
};
use std::str::FromStr;

const TIP_LAMPORTS: u64 = 1_000_000; // 0.001 SOL minimum; raise it under congestion
const TIP_WALLETS: [&str; 11] = [
    "hark1zxc5Rz3K8Kquz79WPWFEgNCFeJnsMJ16f22uNP",
    "harkm2BTWxZuszoNpZnfe84jRbQTg6KGHaQBmWzDGQQ",
    "hark4CwtTnN2y9FaxjcFBAJdJqQrpouu5pgEixfqdEz",
    "harkoJfnM6dxrJydx5eVmDVwAgwC94KbhuxF69UbXwP",
    "hark6hUDUTekc1DGxWdJcuyDZwf6pJdCxd4SXAVtta6",
    "harkoTvFpKSrEQduYrNHXCurARVT19Ud3BnFhVxabos",
    "harkEpXoJv5qVzHaN7HSuUAd6PHjyMcFMcDYBMDJCEQ",
    "harkyXDdZSoJGyCxa24t2QXx1poPyp8YfghbtpzGSzK",
    "harkR2YJ4Dpt4UDJTcBirjnSPBhNpQFcoFkNpCkVqNk",
    "harkRBygM8pHYe4K8eBjfxyEX19oJn3LepFjvNbLbyi",
    "harkYFxB6DuUFNwDLvA5CQ66KpfRvFgUoVypMagNcmd",
];

async fn send_via_relay(
    rpc: &RpcClient,
    payer: &Keypair,
    mut ixs: Vec<Instruction>,
) -> Result<serde_json::Value, Box<dyn std::error::Error>> {
    // The tip: a top-level transfer to a random tip wallet.
    let tip_wallet = Pubkey::from_str(TIP_WALLETS.choose(&mut rand::thread_rng()).unwrap())?;
    ixs.push(system_instruction::transfer(&payer.pubkey(), &tip_wallet, TIP_LAMPORTS));

    let blockhash = rpc.get_latest_blockhash().await?;
    let tx = Transaction::new_signed_with_payer(&ixs, Some(&payer.pubkey()), &[payer], blockhash);

    let res = reqwest::Client::new()
        .post("https://fra.relay.allenhark.com/v1/sendTx")
        .header("x-api-key", "YOUR_API_KEY")
        .json(&serde_json::json!({ "tx": STANDARD.encode(bincode::serialize(&tx)?), "simulate": false }))
        .send()
        .await?;
    Ok(res.json().await?) // {"status":"accepted","request_id":"…","signature":"…"}
}

import base64, random, requests
from solana.rpc.api import Client
from solders.keypair import Keypair
from solders.message import Message
from solders.pubkey import Pubkey
from solders.system_program import TransferParams, transfer
from solders.transaction import Transaction

TIP_LAMPORTS = 1_000_000  # 0.001 SOL minimum; raise it under congestion
TIP_WALLETS = [
    "hark1zxc5Rz3K8Kquz79WPWFEgNCFeJnsMJ16f22uNP",
    "harkm2BTWxZuszoNpZnfe84jRbQTg6KGHaQBmWzDGQQ",
    "hark4CwtTnN2y9FaxjcFBAJdJqQrpouu5pgEixfqdEz",
    "harkoJfnM6dxrJydx5eVmDVwAgwC94KbhuxF69UbXwP",
    "hark6hUDUTekc1DGxWdJcuyDZwf6pJdCxd4SXAVtta6",
    "harkoTvFpKSrEQduYrNHXCurARVT19Ud3BnFhVxabos",
    "harkEpXoJv5qVzHaN7HSuUAd6PHjyMcFMcDYBMDJCEQ",
    "harkyXDdZSoJGyCxa24t2QXx1poPyp8YfghbtpzGSzK",
    "harkR2YJ4Dpt4UDJTcBirjnSPBhNpQFcoFkNpCkVqNk",
    "harkRBygM8pHYe4K8eBjfxyEX19oJn3LepFjvNbLbyi",
    "harkYFxB6DuUFNwDLvA5CQ66KpfRvFgUoVypMagNcmd",
]

def send_via_relay(rpc: Client, payer: Keypair, ixs: list) -> dict:
    # The tip: a top-level transfer to a random tip wallet.
    tip = transfer(TransferParams(
        from_pubkey=payer.pubkey(),
        to_pubkey=Pubkey.from_string(random.choice(TIP_WALLETS)),
        lamports=TIP_LAMPORTS,
    ))
    blockhash = rpc.get_latest_blockhash().value.blockhash
    tx = Transaction([payer], Message.new_with_blockhash([*ixs, tip], payer.pubkey(), blockhash), blockhash)

    r = requests.post(
        "https://fra.relay.allenhark.com/v1/sendTx",
        headers={"x-api-key": "YOUR_API_KEY"},
        json={"tx": base64.b64encode(bytes(tx)).decode(), "simulate": False},
        timeout=5,
    )
    return r.json()  # {"status": "accepted", "request_id": "...", "signature": "..."}