If Clover device works in Offline? I am confusing, whether calling API is best or Calling SDK is best?
I believe SDK will work with local data, once we sync manually or connection established, it will share the data with Cloud API. Am I right?
You are correct, using the Android SDK will work while the Clover device is offline since it works with local data, and any orders/transactions made will be synchronized once an internet connection is established again.
Keep in mind that transactions can only be made on an offline Clover device for seven consecutive days, after which transactions will not be allowed until the Clover device is connected to the internet again.
So the choice of using REST API or Android SDK is up to you, although as you mentioned Android SDK does have the benefit of being able to work with local data on the Clover device.