Modeling RESTful Conversations with Extended BPMN Choreography Diagrams

RESTful Web APIs often make use of multiple basic HTTP interactions to guide clients towards their goal. For example, clients may get redirected towards related resources by means of hypermedia controls such as links. Existing modeling approaches for describing RESTful APIs expose low-level HTTP details that help developers construct individual requests and parse the corresponding responses. However, very little attention has been given to high-level modeling of RESTful conversations, which abstracts the structure of multiple HTTP interactions. To address such issue in this paper we introduce an extension of the notation used in BPMN choreography diagrams. Its purpose is to represent concisely all possible interaction sequences in a given RESTful conversation.