Proof Of Payment

This is the authorization flow in which the server can verify if a user has made certain required payment without knowing the identity of the user.

The OZKi Bot demo application implements this proof of payment flow with PayPal as the payment processor. The narratives with the OZKi Bot are such that the user must pay for the OZKi Bot PayPal subscription before using it. Once the user has paid for the subscription, PayPal creates a billing id associated with the payment, which the user uses to create the proof of payment.

Details of the interactions among the Paypal server, OZKi oracle server, the user (browser), and the OZKi Bot server are illustrated in this call sequence diagram.