We are currently considering whether it is possible to link our proprietary system with Shopify via API. I have a question about errors that may occur in the linked data. For example, if the error occurs during an update of existing data, I believe that the data will be transmitted if the "update" is performed again. However, in the case of new registrations (such as customer information, order information, and product information), registration is only done once. If the data that should be sent via API is not transmitted during a new registration, how should we resend it?
Not entirely sure of the usecase from your description, but if there is an error when the data is transmitted to shopify then it will show in the http response headers. You would track that and do a retry I would imagine.