Recent Items returns information about files that have been accessed by a user not long ago. It keeps track of items that were accessed either in the last 90 days or the last 1000 items accessed (both conditions must be met).
Get a list of all recent items the user has by calling
GetRecentItemsAsync(int limit = 100, string marker = null, IEnumerable<string> fields = null, bool autoPaginate = false).
BoxCollectionMarkerBasedV2<BoxRecentItem> recentItems = await client.RecentItemsManager
.GetRecentItemsAsync(limit: 500);