I’ve released a simple demo server using python/flask which verifies payment via Vanilla. You can find it on github. Contributions, questions, suggestions welcome. I learned of the WM public verification server in this thread and will be adding support for that soon.
The server works by creating a session when a client has a verified payment, and provides a simple bit of client side code to trigger that when a payment is made. It’s meant as a demo/inspiration currently, but will do some work to package it up a bit more formally & add some tests if there’s interest.