Comment envoyer des transactions Solana

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

const connection = new Connection("YOUR_RPC_URL");
const fromKeypair = Keypair.generate(); // Assume this is funded
const toPubkey = Keypair.generate().publicKey;

// 1. Build your instructions
const instructions = [
  SystemProgram.transfer({
    fromPubkey: fromKeypair.publicKey,
    toPubkey: toPubkey,
    lamports: 0.001 * LAMPORTS_PER_SOL,
  }),
];

// 2. Get a recent blockhash
const { blockhash } = await connection.getLatestBlockhash();

// 3. Compile the transaction message
const messageV0 = new TransactionMessage({
  payerKey: fromKeypair.publicKey,
  recentBlockhash: blockhash,
  instructions,
}).compileToV0Message();

// 4. Create and sign the transaction
const transaction = new VersionedTransaction(messageV0);
transaction.sign([fromKeypair]);

import { ComputeBudgetProgram } from "@solana/web3.js";

// Create a test transaction with a high compute limit to ensure simulation succeeds
const testInstructions = [
    ComputeBudgetProgram.setComputeUnitLimit({ units: 1_400_000 }),
    ...instructions, // Your original instructions
];
const testMessage = new TransactionMessage({
    payerKey: fromKeypair.publicKey,
    recentBlockhash: blockhash,
    instructions: testInstructions,
}).compileToV0Message();
const testTransaction = new VersionedTransaction(testMessage);
testTransaction.sign([fromKeypair]);

// Simulate the transaction to get the exact CUs consumed
const { value: simulationResult } = await connection.simulateTransaction(testTransaction);

if (!simulationResult.unitsConsumed) {
  throw new Error("Simulation failed to return unitsConsumed");
}

// Add a 10% buffer to the CU estimate
const computeUnitLimit = Math.ceil(simulationResult.unitsConsumed * 1.1);

// Create the instruction to set the CU limit
const setCuLimitInstruction = ComputeBudgetProgram.setComputeUnitLimit({
    units: computeUnitLimit,
});

// The transaction needs to be serialized and base58 encoded
const serializedTransaction = bs58.encode(transaction.serialize());

const response = await fetch("YOUR_RPC_URL", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
        jsonrpc: "2.0",
        id: "1",
        method: "getPriorityFeeEstimate",
        params: [
            {
                // Pass the serialized transaction
                transaction: serializedTransaction, 
                // Use 'recommended' for Helius's staked connections
                options: { recommended: true },
            },
        ],   
    }),
});
const data = await response.json();

if (!data.result || !data.result.priorityFeeEstimate) {
    throw new Error("Failed to get priority fee estimate");
}

const priorityFeeEstimate = data.result.priorityFeeEstimate;

// Create the instruction to set the priority fee
const setPriorityFeeInstruction = ComputeBudgetProgram.setComputeUnitPrice({
    microLamports: priorityFeeEstimate,
});

// 1. Add the new instructions to your original set
const finalInstructions = [
  setCuLimitInstruction,
  setPriorityFeeInstruction,
  ...instructions,
];

// 2. Re-build and re-sign the transaction with the final instructions
const { blockhash: latestBlockhash, lastValidBlockHeight } = await connection.getLatestBlockhash();

const finalMessage = new TransactionMessage({
  payerKey: fromKeypair.publicKey,
  recentBlockhash: latestBlockhash,
  instructions: finalInstructions,
}).compileToV0Message();

const finalTransaction = new VersionedTransaction(finalMessage);
finalTransaction.sign([fromKeypair]);

// 3. Send the transaction
const signature = await connection.sendTransaction(finalTransaction, {
  skipPreflight: true, // Optional: useful for bypassing client-side checks
});

// 4. Implement a polling loop to confirm the transaction
let confirmed = false;
while (!confirmed) {
    const statuses = await connection.getSignatureStatuses([signature]);
    const status = statuses && statuses.value && statuses.value[0];

    if (status && (status.confirmationStatus === 'confirmed' || status.confirmationStatus === 'finalized')) {
        console.log('Transaction confirmed!');
        confirmed = true;
    }

    // Check if the blockhash has expired
    const currentBlockHeight = await connection.getBlockHeight();
    if (currentBlockHeight > lastValidBlockHeight) {
        console.log('Blockhash expired, transaction failed.');
        break;
    }
    
    // Wait for a short period before polling again
    await new Promise(resolve => setTimeout(resolve, 2000)); 
}

https://mainnet.helius-rpc.com/?api-key=YOUR_API_KEY&mev-protect=true