Currently, I don’t think there is a way to tell if an item is assigned to a member area or not.

It would be good to have the secured status of an item available in the liquid output so we can filter/sort by it (eg: use it to filter out secure items from a list if needed, or visually mark an item as secured content…)

"IsSecure": true/false

Or perhaps better still, or as well as, output the assigned zones in an array:

"MemberAreas": [
    "Area 1", 
    "Area 2",
    ...
]