I'm setting up a payment engine for a custom framework using PayPal Express Checkout. One of the business requirements is adding support for recurring payments. I've found documentation on how to implement this at https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/e_howto_api_ECRecurringPayments
The thing I don't quite understand is how to retrieve the value of BillingType from the API after I've set it via SetExpressCheckout to "RecurringPayments". It doesn't seem to appear anywhere in the response data I get back from neither GetExpressCheckoutDetails nor DoExpressCheckoutPayment. I need this to know whether I need to create a recurring payments profile or not. So as far as I can tell my only option is to store the value of BillingType in my database and query it again after DoExpressCheckoutPayment. This works for me but I find it odd that this data would not be returned at all by the API. Am I missing something? Or is there another way of correctly implementing recurring payments?