How to get assignment of a reminder (EKReminder) in iOS?

[Update: I submitted an official Apple Developer feedback request for an update to the EventKit API and documentation]

[Update: I contacted Apple Support and they said to read the docs...so I think Matt is correct, It is simply not available.]

According to Apple Docs, the EKReminder is a subclass of EKCalendarItem. It has the following (lot) of properties:

As a reminder:

• priority: Int - The reminder's priority.
• startDateComponents: DateComponents? - The start date of the task.
• dueDateComponents: DateComponents? - The date by which the reminder should be completed.
• isCompleted: Bool - A Boolean value determining whether or not the reminder is marked completed.
• completionDate: Date? The date on which the reminder was completed.

As a calendar item:

• title: String! -The title for the calendar item.
• location: String? - The location associated with the calendar item.
• creationDate: Date? - The date that this calendar item was created.
• lastModifiedDate: Date? - The date that the calendar item was last modified.
• timeZone: TimeZone? - The time zone for the calendar item.
• url: URL?
• hasNotes: Bool - A Boolean value that indicates whether the calendar item has notes.
• notes: String? - The notes associated with the calendar item.
• hasAttendees: Bool - A Boolean value that indicates whether the calendar item has attendees.
• attendees: [EKParticipant]? -The attendees associated with the calendar item, as an array of EKParticipant objects.

I can print any one of these items from reminders in my app.

However, if I create a reminder that is "assigned to a person", I cannot get that information. I know it must be stored somewhere.

If you "print" a reminder, you get something like this:

EKReminder <0x0000000> {title = Do the thing; dueDate = 2021-02-25 08:00:00 +0000; completionDate = (null); priority = 0; calendarItemIdentifier = XXXXX-XXXX-XXXX-XXXX-XXXXXX; alarms = (null)}

If you want, you can "print" any of the other items, like print(reminder.notes!).

I thought shared items and assignments might use the attendees property, but it is nil - even when the reminder has an assigned person.

How can you get to the assigned person?

This is probably a feature of upgraded reminders. But the API was never upgraded to match, so there’s no programmatic access to it.