Depending on the field of application, the core element of Swagger is either a JSON or a YAML file. The user interface (UI), which provides an easy way of creating the API documentation, is based on HTML and JavaScript. Put simply, Swagger is language-neutral and machine-readable. Via the user interface, developers can not only manage documentation, but also use Swagger to run ad-hoc tests.
One advantage of Swagger is its comprehensive extension mode, which is supported by a core library known as the Swagger Core. The user interface is called Swagger UI and the code generator is called Swagger Codegen. There is also a Swagger Editor.
However, Swagger’s greatest strength – as with many open-source solutions – comes from its extensive ecosystem on GitHub. There are code generators for almost every programming language. Swagger documents each interface with all the necessary information.
The documentation file starts with the specification version number, and then gives the general information about the API, clearly organised under the ‘info’ category. Swagger also separates out the host, the path, and URL schemes and specifies each of these. After this it gives the MediaType for the entire API. You can think of the structure like a complex index card system.
Once everything has been categorised, the content is presented: paths, operators, and parameters and their descriptions are prepared. Data types are dealt with in a separate section. In the Swagger UI, everything can be displayed both in text form and graphically. This is especially useful when sending direct test requests from a browser. This combination of perfect documentation and the ability to generate direct API requests is what makes Swagger so valuable.