From the UK-based open monograph project [COPIM](https://copim.pubpub.org/pub/sign-up-system-on-github/):
> Available on Github at [https://github.com/BirkbeckCTP/otf-signup](https://github.com/BirkbeckCTP/otf-signup), features of the system include order tracking, billing management, notification of new sign ups, and access control for backlist packages of books.
The [open source code](https://github.com/BirkbeckCTP/otf-signup)—developed for the [CEU Press initiative](https://ceup.openingthefuture.net/) to use back-catalogue access membership to fund current OA publishing—should be adaptable to any consortiable funding model. Can't wait to dive in.