Q:

How do I create multiple chats using the same app key?

We allow our creators to create their own site, so how do we get one chat per site? How do we create multiple chats using one single getsteam app? Each site will have multiple users also. The users of each site have to participate in the corresponding chat.

A:

One simple approach is to namespace users and channels with sites' unique ID. This way you can keep everything under one account and use the same API key without mixing data.
When doing so, make sure to enforce a naming convention for the namespace (ie. site-{id}-{user_id}) and only create channels and users server-side. 

