You can request an OpenAI API key from your users and add manually to their workspace or widget. You can change this in the widget settings, as well as the admin settings.
You can also pause your clients workspace sub-accounts for non-payment, giving you a way to further gate access to your tools.
*Please note, there is no built-in re-billing feature or integration in the Inbounder platform. Should agencies wish to resell workspaces, you will need to manually invite team members to your workspaces, and charge your clients externally.