Webhooks

Set a Webhook URL (HTTPS) in the app’s settings and choose the events you want:

Event	Sent when
channel_occupied	A channel gets its first subscriber
channel_vacated	A channel loses its last subscriber
member_added	A user joins a presence channel
member_removed	A user leaves a presence channel
client_event	A client sends a client event

Events are sent as a POST with a JSON body, batched for up to one second:

{
  "time_ms": 1760781600000,
  "events": [
    { "name": "channel_occupied", "channel": "presence-lobby" },
    { "name": "member_added", "channel": "presence-lobby", "user_id": "42" }
  ]
}

Verifying the signature

Every request carries X-Pusher-Key (your app key) and X-Pusher-Signature, the hex HMAC-SHA256 of the raw body with your app secret. The Pusher server libraries verify it for you:

const webhook = pusher.webhook({ headers: req.headers, rawBody: req.rawBody });
if (!webhook.isValid()) return res.sendStatus(401);
for (const event of webhook.getEvents()) {
  // ...
}

Answer with any 2xx status. A failed delivery (timeout after 5 seconds, or a non-2xx answer) is retried three times, after 1, 5 and 30 seconds. Redirects are not followed.