Factors influencing REST API usability

REST API usability, both in design and learning materials, affects API adoption rates. Bad usability and insufficient or hard to use documentation can make developers search for material outside of provided learning materials, hindering new API learning and introducing possible blockers in API adoption.

The initial REST API design is a crucial step where developer experience and usability should be kept in mind. However, there is a lack of usability guidelines for application developers. This paper conducts a literature review on the current state of REST API usability, aiming to figure out what affects developer experience in REST APIs and what the major bottleneck client developers face when learning a new REST API.

Documentation, its content and structure, is seen as a major factor in usability and REST API learning. Documentation that is easy to navigate, provides practical code examples for developers with an opportunistic learning style, and is up to date and complete has a positive impact for developers learning new REST APIs. In contrast, outdated, incomplete, inconsistent, and hard to navigate documentation hinders learning of the API and makes developers rely more on experimentation, and outside materials, leading to a slower learning process and bigger failure rate.