Taler (Payment)Payer (Shopper) BrowserPayer (Shopper) BrowserPayee (Merchant) SitePayee (Merchant) SiteTaler ExchangeTaler ExchangeTor/HTTPSHTTP/HTTPSRequest OfferChoose goods by navigating to offer URLSend signed digital contract proposaloptSelect Taler payment method (skippable with auto-detection)Execute PaymentoptAffirm contractNavigate to fulfillment URLSend hash of digital contract and payment informationSend paymentForward paymentConfirm paymentConfirm paymentFulfilmentReload fulfillment URL for deliveryProvide product resource