I am delighted to announce that version 163 of Hook software integration is now available, which adds support for 
BibDesk. Quoting Wikipedia:
BibDesk is an open-source reference management software package for macOS, used to manage bibliographies and references when writing essays and articles.[1][2][3] It can also be used to organize and maintain a library of documents in PDF format and other formats. It is primarily a BibTeX front-end for use with LaTeX, but also offers external bibliographic database connectivity for importing, a variety of means for exporting, and capability for linking to local documents and automatically filing local documents. It takes advantage of many macOS features such as AppleScript and Spotlight.
The URL format is x-bdsk://citekey. For example: x-bdsk://maddison2006world.
See also How to Use BibDesk for Mac - YouTube.
I (and/or others) will add more info here. We’ll also extend this new web page: Using Hook with BibDesk Mac App — Reference Management Software.
Supporting knowledge workers
Hook is designed for knowledge-intense work; so it is very important to support academic software and workflows. Last year I myself switched from Papers app reference management software, which went all web and dropped automation. I want my PDF files to be local , not on a server, and to follow my own naming conventions.
Skim PDF app, also supported by Hook, has BibText/BibDesk support.
It is not surprising that a significant % of our users are academics, other researchers, lawyers, writers and/or developers.
We have more surprising / original features in the works to support knowledge-intense work. (Related: I’m developing ideas about innovation from a cognitive science perspective that will figure in Discontinuities: Love, Art, Mind, my next book. I’m developing / updating the concept of creativity , extending some of the ideas in Cognitive Productivity books. See for example Maggy Boden’s book, The Creative Mind. Maggy was my external Ph.D. examiner.)
How to get the updated integration
Hook’s automatic software update (if enabled) automatically updates Hook’s integration scripts without you needing to relaunch Hook. Using Hook’s Check for App Updates and Update Scripts command also updates the scripts, without you needing to relaunch Hook.
Gratitude
This software integration is courtesy of Christiaan Hofman, renown developer of BibDesk and Skim PDF app reader. Innovative ways of using Skim for delving are discussed in my Cognitive Productivity books. I’ve had the pleasure of exchanging occasional emails with Christiaan over the years. I even had a little R&D project to extend Skim, almost 10 years ago now. But I digress.
Thanks also to Matthew Heun for getting the integration ball rolling on SourceForge and here as @mkh Hook integration with BibDesk.