This isn't obvious. How do you decide what to do with the information you receive? How do you encode "Oh, this service lets you tweet, but this one lets you on

This isn't obvious. How do you decide what to do with the information you receive? How do you encode "Oh, this service lets you tweet, but this one lets you only share links?" How do you have a protocol that lets you handle both Twitter and Google Calendar? At one point you're basically making a protocol that's a programming language, and we already have JSON + most languages. So the answer to this is "JSON, or whatever other dictionary serializer you like".