Up! please this is very easy: help.convertri.com/article/107-how-to-use-webhooks
Webhooks are definitely available (at least, I see this "Set your webhook secret key. If you don't know what this is you can safely ignore it." in my profile). I'd love to be able to move from purchase-on-Convertri-landing-page to add-to-membership-site or add-to-course or even just add-to-mailing-list!