As its name suggests, these are APIs that serve a unique and specific purpose, typically derived from an unambiguous need associated with a user journey or use case. Because of this, they aren't suitable for reuse outside the context which they are built for.
In terms of guiding principles, apart from the ones prescribed in the RESTful definition, there is a fair degree of flexibility as to how a single-purpose API is defined. The key and main requirement for this type of APIs is ensuring that it satisfies the explicit needs of its consumers in the best possible manner.
Let's take, for example, the landing page of the MRA's customer mobile app.
Being the first screen displayed when the app opens, it usually shows summary ...
