# WebSocket Reconnect

> Restore Solana subscriptions after a WebSocket disconnect.

Canonical: https://nolimitnodes.com/docs/guides/websocket-reconnect

A new WebSocket connection starts with no subscriptions. Store your desired subscriptions and send them again after every reconnect.

## Reconnect flow

1. Detect the close event.
2. Wait with exponential backoff and jitter.
3. Open a new authenticated connection.
4. send each subscription request again.
5. Replace old subscription IDs with new IDs.
6. Resume downstream processing.

## Node.js example

```javascript

const desired = [
  {
    key: "slots",
    method: "slotSubscribe",
    params: [],
  },
]

let attempt = 0
let stopped = false

function connect() {
  const socket = new WebSocket("wss://ws.nln.clr3.org", {
    headers: { "x-api-key": process.env.NLN_API_KEY },
  })

  socket.on("open", () => {
    attempt = 0
    for (const [index, sub] of desired.entries()) {
      socket.send(JSON.stringify({
        jsonrpc: "2.0",
        id: `${sub.key}:${index}`,
        method: sub.method,
        params: sub.params,
      }))
    }
  })

  socket.on("message", (raw) => {
    const message = JSON.parse(raw.toString())
    console.log(message)
  })

  socket.on("close", () => {
    if (stopped) return
    const base = Math.min(30_000, 500 * 2 ** attempt)
    const delay = base + Math.floor(Math.random() * 250)
    attempt += 1
    setTimeout(connect, delay)
  })
}

connect()

process.on("SIGTERM", () => {
  stopped = true
})
```

## Handle gaps

WebSocket subscriptions do not replay missed notifications.

- Store the latest processed slot.
- Read missed state through JSON-RPC after reconnect.
- Use Yellowstone replay when slot replay fits your plan.
- Make downstream writes idempotent.