Digital receipt mechanism?

[msporny]

How is a digital receipt achieved in the .payment() API? For example, how does the customer assert proof of ownership? Is there a data portability capability for customers to transfer their purchases from one Payment Provider to another?

[kumar303]

Currently, the merchant implements a postback handler in order to verify that a customer owns a product. This is meant to prove that a payment happened, not that a customer has purchased an asset. It has a couple problems:

• It only happens during purchase. A customer cannot switch devices and prove to the merchant "I own this asset."
• It is specific to a payment provider. For example, if a customer pays through Mozilla's payment provider, the merchant must process a postback from Mozilla using a shared secret. If the customer pays through Acme payment provider, the merchant must process a postback in the same format but it must use a different shared secret between them and Acme.

If we specified a digital receipt then I think we could gain a couple nice features:

• developers will have an easier time supporting multiple payment providers
• developers will not have to invent their own user asset ownership system
• two web apps could sell the same content (although this has complications around permission to sell assets)