How to get unread message count for channels that im not a member of?

Hello,
I’m trying to figure out how to get the unread message count for channels the user has not joined (Javascript SDK).
Every time I join a channel, I have the correct count and correct “myLastRead” timestamp.
When I leave a channel, the count and timestamp get zeroed.
Is there a way to know if the channel has new messages even when I have not joined it?
Thanks.

If you leave the channel, then you lose all information about it… That’s the idea of being member of a channel.

If you need to provide this information to your connected users, you will have to use Platform API:

/v3/users/your-user-id-here/my_group_channels

The response will include all user’s information about each of his channels.

You can’t from SDK since all you do from SDK will work for the connected user.