I'm looking at building a tool that can set the notes for other users on my company's local Skype for business server, providing automated note updates for participating users in my program.
I've found https://msdn.microsoft.com/en-us/skype/ucwa/setmynoteinformation - which provides guidelines on how to set a user's own personal note. Is there an endpoint that an application (with the appropriate permissions) could access to do something similar for other users?
I see the UCWA documentation for https://msdn.microsoft.com/en-us/skype/ucwa/contactnote_ref - but this appears to be a single user centric API for reading a contact's notes. TrustedApplicationAPI looks to mostly relate to meetings - https://ucwa.skype.com/trustedapplicationapi/reference/Resources.html
Is this something that can be done through a REST interface?
Not with UCWA, which isn't designed for doing operations on-behalf-of user; and so will require you to impersonate the user you want to update the note for.
The only option for you will be running a UCMA instance for the purpose (if you're on-premises), and expose that functionality via a custom REST service