For Final Cut Pro, collaboration relies on Library Locking. In Postlab, an FCP Library is added as a Document inside a Production. Once a Library's opened from a Production, Postlab locks that Library for your exclusive use. If another Team Member accesses that Library, Postlab identifies who locked the Library, from which computer, and when.
To unlock the Library for another Team Member, upload your work in Postlab. Postlab automatically closes your Library in FCP and removes the lock from your Library.