The &quot;client-less&quot; approach would be particularly nice for use with IoT devices which don&#x27;t have enough CPU&#x2F;memory to run a beefy pub&#x2F;sub client (which is typical of other solutions). So that&#x27;s nice.<p>Is there a way to perform access control on the backend? E.g. Is there a way to prevent a specific user from subscribing to a specific channel (if they are not allowed)? Or is this specifically designed to deal only with public channels (that anyone can publish&#x2F;subscribe to)?