The BigOven Plugin PHP Sample Code by Chris Pliakas demonstrates how to access the API via Key, username, and password using dummy tests. Authentication displays a successful response after requesting a particular query.
Edamam, a company committed to helping people eat better by using technology to capture, organize and distill "the world's food knowledge," announced at NY Tech Day the release of the Edamam Nutrition API so that third-party developers can use the Edamam platform to create innovative food and recipe applications.
Food-sharing mobile photo app Foodspotting had an API since day one. Of course, every mobile app has an API, at least if it needs to store or retrieve non-trivial data. Most of those interfaces stay hidden away, private APIs with only that single, internal audience. Foodspotting, on the other hand, signed Zagat as an early partner and now also has OpenTable, among others, using its Foodspotting API. The company is not exactly making it widely available for any developer, though the documentation is public, planting it in a vast grey area that's becoming increasingly common.