MemberPress has built-in support for bbPress forums protection. There's a couple of options which we'll explore below to help you decide which method will work best for you.
Protecting ALL forums
The easiest way to protect ALL forums, topics, and replies is to create a Custom URI Rule in MemberPress for /forums or whatever you're using for your forums base slug.
The Rule should look something like the below:
This works best if you have the Prefix all forum content with the Forum Root slug (Recommended) option enabled in the bbPress settings:
Protecting Some Forums
In some cases, you may want some of your forums to be public, and others to be for members only.
For this, it's best to create a new Rule for each forum you want protected as shown below:
The protected forum will still show up on your main forum listing page, but if a guest or non-member clicks on the forum, they will be redirected to the login or unauthorized page on your site.
All topics and replies within these forums will be hidden or protected as well, and will redirect to the login or unauthorized page if viewed directly by an unauthorized user.
Your forums can now be left open and public as MemberPress will handle the protection instead: