question

As you said, allowing players to directly call the client API AddUserVirtualCurrency may cause players to cheat by adding virtual currency to their accounts directly on the client. The main advantage of cloud scripts is that you can execute logic on the server side, rather than on the client side. For example, you can create a cloud script for adding virtual currency to the player, and you can add some check logic to the cloud script. This function could check if the conditions for adding currency are met (such as if the player completing a quest). Then, the API AddUserVirtualCurrency is actually called only if these conditions are met. This way, even if the player tries to call the API ExecuteCloudScript multiple times, they will only get the currency if the conditions are met. As for why we don't recommend you add these logic checks on the client and let players call the Client API AddUserVirtualCurrency directly, this is because the client code can be accessed and modified by players, and players may bypass the check mechanism and directly add virtual currency to their accounts.