Presence

Can I be notified over HTTP when someone enters or leaves a channel?
Yes, this is supported using WebHooks. You can register for HTTP events to pushed to your servers using WebHooks whenever a client enters, updates the...
Tue, 1 Mar, 2016 at 1:07 PM
Why don't presence members leave as soon as I close a tab?
If you're using the javascript client, ably-js, you may have noticed that if you close a tab (or refresh the page etc.), it takes 15 seconds for any...
Wed, 9 Nov, 2016 at 8:45 PM
What happens if I exceed the number of members present on a channel?
To avoid any confusion about terminology used, the number of clients that can be attached and subscribed to a channel is unlimited. See the channel pub/s...
Wed, 7 Dec, 2016 at 8:08 AM
Why do you have a limit on the number of members present on a channel?
To avoid any confusion about terminology used, the number of clients that can be attached and subscribed to a channel is unlimited. See the channel pub/sub...
Sat, 18 Aug, 2018 at 6:05 PM
Can a single user be present multiple times on the same channel?
Yes, that is perfectly valid from our perspective.  For example, if a user is present on a channel in their browser and also on their mobile device, then th...
Fri, 5 May, 2017 at 6:57 PM
Can I change the length of the presence timeout?
This is not a feature we offer at this time.
Thu, 26 Jul, 2018 at 8:43 AM
I don't understand why I see so many presence messages in my stats. Can you help?
Ably's presence is a powerful feature that allows client devices to subscribe in real time to presence events such as as when users enter, update or le...
Sat, 18 Aug, 2018 at 6:04 PM
How can I see which channels are currently active?
You can go to https://rest.ably.io/channels?key=<redacted>, where <redacted> is the key you want to see the channels associated with.
Mon, 3 Sep, 2018 at 5:57 PM