Streams

// Node 22+ or any browser. Reconnects and resumes after short gaps.
const topics = ['large_trades:5000', 'launches'];
let epoch = null, seq = 0;

function connect() {
  const ws = new WebSocket('wss://yolo.casa/api/v1/stream');
  let alive = Date.now();
  ws.onopen = () => {
    // Optional: a key raises the limits. Leave it out to stay anonymous.
    if (process.env.YOLO_API_KEY)
      ws.send(JSON.stringify({ op: 'auth', key: process.env.YOLO_API_KEY }));
    ws.send(JSON.stringify({
      op: 'subscribe', topics,
      ...(epoch ? { resume: { epoch, seq } } : {}),
    }));
  };
  ws.onmessage = (e) => {
    alive = Date.now();
    const m = JSON.parse(e.data);
    if (m.type === 'hello') epoch = epoch ?? m.epoch;
    if (m.type === 'resume_failed') { epoch = m.epoch; seq = m.seq; /* refetch over REST */ }
    if (m.type === 'event') { seq = m.seq; console.log(m.channel, m.topics, m.data); }
  };
  // The server pings every 15 s. Silence for 45 s means the link is dead.
  const watch = setInterval(() => { if (Date.now() - alive > 45_000) ws.close(); }, 5_000);
  ws.onclose = () => { clearInterval(watch); setTimeout(connect, 1_000); };
}
connect();