Date for the returned assignment.
For a resource, this is the last time that particular resource was updated.
A unique number identifying the assignment.
The kind of object returned.
The URL of the requested resource.
OptionalcodeA resource will never have a code property.
OptionalerrorA resource will never have an error property.
Assignments contain information about a user's progress on a particular subject, including their current state and timestamps for various progress milestones. Assignments are created when a user has passed all the components of the given subject and the assignment is at or below their current level for the first time.
See
https://docs.api.wanikani.com/20170710/#assignments