Box released the Folder Lock API for General Availability! The Folder Lock API provides the ability to lock down a folder to prevent it from being moved or deleted.
For more information, check out the resources below:
Blog: https://medium.com/box-developer-blog/new-folder-lock-apis-fb79161a1089
User Guide: https://developer.box.com/guides/folders/single/create-lock/
API Reference: https://developer.box.com/reference/post-folder-locks/