I built a library to access CloudKit Web Services via Swift. Why?
Because the CloudKit framework is not available outside of Apple operative systems. Therefore, if you are doing anything server-side (i.e. Linux) then you can use MistKit to swiftly access CloudKit via the web services. I use this specifically for my app Heartwitch.
Version 0.2.0 includes built-in support and helpers for SwiftNIO and Vapor.
Your input and feedback is great appreciated!