Basically YAP is a platform to host your web application on Yahoo! pages. When your app is accessed on Yahoo!, YAP requests your server for the markup to be displayed on the page. The request would contain information about the user and access tokens to fetch user's data using various Yahoo! APIs. There is no JSON involved here in a normal render flow of an app.

Can you elaborate your question please?

Yahoo pipes has a web service module but it requires http post for json and a json return, i just figured why can't yap do that. Not the standard but the non standard. The standard is hosted directly on your site but the second type isn't