preprocessedSubscribe 사용 방법

wss://beta.helius-rpc.com/?api-key=<API_KEY>

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "preprocessedSubscribe",
  "params": {
    "accountInclude": ["JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4"],
    "accountExclude": [],
    "accountRequired": []
  }
}

{
  "jsonrpc": "2.0",
  "result": 1,
  "id": 1
}

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "preprocessedSubscribe",
  "params": {
    "accountInclude": ["JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4"],
    "accountExclude": ["Vote111111111111111111111111111111111111111"],
    "accountRequired": []
  }
}

const WebSocket = require('ws');
const bs58module = require('bs58');
const bs58 = bs58module.default ?? bs58module;

const ws = new WebSocket('wss://beta.helius-rpc.com/?api-key=<API_KEY>');

ws.on('open', () => {
  ws.send(JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'preprocessedSubscribe',
    // Only Jupiter v6 transactions — accountInclude/accountRequired must
    // specify at least one account between them.
    params: {
      accountInclude: ['JUP6LkbZbjS1jKKwapdHNy74zcZ3tLUZoi5QNyVTaV4'],
      accountExclude: [],
      accountRequired: []
    }
  }));

  // Keep the connection alive
  setInterval(() => ws.ping(), 30_000);
});

ws.on('message', (data, isBinary) => {
  // The subscribe acknowledgement arrives as a JSON text frame
  if (!isBinary) {
    const msg = JSON.parse(data.toString());
    if (msg.id === 1) console.log('Subscribed, ID:', msg.result);
    return;
  }

  // Notifications arrive as binary frames:
  // version (u8) | slot (u64 LE) | signature ([u8; 64]) | bincode(VersionedTransaction)
  const buf = Buffer.from(data);
  const version = buf.readUInt8(0); // currently 1 — branch on this if it changes
  if (version !== 1) return; // unknown schema version; update your decoder
  const slot = buf.readBigUInt64LE(1);
  const signature = bs58.encode(buf.subarray(9, 73));
  const txBytes = buf.subarray(73); // bincode-serialized VersionedTransaction

  console.log('Preprocessed transaction:', { slot, signature, bytes: txBytes.length });
  // Deserialize txBytes (bincode) into a VersionedTransaction with your Solana tooling
});

ws.on('error', console.error);
ws.on('close', () => process.exit(1));