Are you guys plan to support server api for 'Purchase Item'? Suppose that we purchase item using client api and that item has abilities then as I worked around it should call 'UpdateUserInventoryItemCustomData' from the client again. so it takes longer time in mobile network situation. But if 'PurchaseItem' is also server api then we can make it together in server side using CloudScript. plus it takes small time because server to server ping-pong.
Brian Choi