--- title: Connection Lifecycle description: Heartbeat, reconnection strategies, and best practices for WebSocket connections. --- # Connection Lifecycle ## Heartbeat Send a ping every **30 seconds** to keep the connection alive:

{
  "type": "ping",
  "timestamp": 1769056941234
}

The server responds with:

{
  "type": "pong",
  "timestamp": 1769056941234
}

If the server receives no ping within 60 seconds, it closes the connection. ## Reconnection strategy Network disruptions are inevitable. Your client should handle disconnections gracefully with exponential backoff: 1. On disconnect, wait a short initial delay (e.g., 1 second). 2. On each failed reconnection attempt, double the delay up to a maximum (e.g., 30 seconds). 3. Add random jitter to prevent thundering herd when many clients reconnect simultaneously. 4. After reconnecting, re-authenticate and re-subscribe to all channels on that connection.

const BASE_DELAY = 1000;
const MAX_DELAY = 30000;
let attempt = 0;


function reconnect() {
  const delay = Math.min(BASE_DELAY * Math.pow(2, attempt), MAX_DELAY);
  const jitter = delay * 0.5 * Math.random();
  setTimeout(() => {
    attempt++;
    connect(); // your connection logic
  }, delay + jitter);
}


function onConnected() {
  attempt = 0; // reset on successful connection
  authenticate();
  resubscribe();
}

## Best practices - **One connection per endpoint family** -- share one `book` connection for orderbook channels and one `nonbook` connection for everything else, rather than opening one connection per subscription. - **Subscribe in batches** -- send all channels in a single `public/subscribe` message rather than one message per channel. - **Handle backpressure** -- keep your message handler lightweight. Offload heavy processing (database writes, analytics) to a background queue. - **Track subscriptions client-side** -- maintain a local registry of active subscriptions so you can re-subscribe after reconnection. - **Use compression** -- enable `brotli` compression to reduce bandwidth, especially for high-frequency channels like `TRADE` and `BLOCK_BOOK_SNAPSHOT`.