Here’s a plugin that allows you to restrict access – I use it together with a custom Role to run a premium pay-only forum for one of my sites:
https://bbpress.org/plugins/topic/hidden-forums/
But we have to handle the Paypal subscriptions manually… it’s a bit of a pain, but worth it of course!
Have you looked into automating the procedure at all with the PayPal recurring payments system? I was thinking about creating a separate ‘advanced’ roles table, which WP and bbP check to see if that user should have access to certain content.
This table would log the user ID and keep the callback from PayPal, and when their time was set to expire so they would lose access should they cancel their auto renew payments.
You could do that with a third plugin for sure. I haven’t automated it because rebilling through Paypal is a pain… so I have someone manage it manually.
I think WordPress MU has a plugin that does something similar. Maybe you could adapt that?
I may have to start doing it manually, then either adapt an existing plugin, or get my head around it myself at a later stage. They’re really banging on about it at work right now 
as a must have ASAP feature. It’s all about the monies!
Well _ck_’s excellent Hidden Forums plugin will get you started. Let me know if you need help with the Custom Role plugin. Or if you’re using bbPress 1.0, there’s a Role Manager plugin that should do the trick!
This thread is old so I’m closing it.
Premise, Easy Digital Downloads, WooCommerce (and more) all have the ability (through extensions) to create forums specifically and only for customers. There is no shortage of solutions. Plus you’re not limited to PayPal, unlike the solution posted above.
