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Application Programming Interface or API is a concept in software technology that defines the interactions between multiple applications and data exchange. Developers use APIs to write software, and the interface is how non-programming users interact with applications on their devices.
An API works by helping an application retrieve specific types of information from another application. The API returns data that it can support within its framework. Whenever users request applications and the API doesn’t recognize the input, then no data is returned.
REST API, also known as Representational State Transfer API, is an architectural style for building an application program interface that uses HTTP requests to use and access data. REST API uses HTTP as a transport mechanism for both its requests and responses. REST is a style and not a standard protocol; this is why REST APIs are sometimes called RESTful because they follow a style. They use JSON message format among other formats like XML, RSS, CSV, HTML, and Atom.
REST APIs work by focusing on users’ resources through URLs and ways to access them rather than the actions. These URLs are usually accompanied by a method by which a user wants to access the information. REST does not make use of cache in its functions. This means that the API will not remember a user’s initial query even if it is like the current request, and the responses will not lean on this aspect.
RESTful APIs use a series of commands and existing HTTP methodologies such as GET, PUT, POST, and DELETE to obtain resources. While working on delivering requests, REST APIs and the users they serve have some form of an understanding, stipulated in a clear way for effective communication. This clear communication is obtained by outlining its various aspects in the documentation.
REST API Documentation
APIs that provide a smooth and enjoyable user experience for developers are top of the list for Application Programming Interface tools picks. In other words, behind a positively popular API, there is a string of happy developers who recommend it. How users interact with the interface and the information therein is determined by principles, including documentation. API documentation is a crucial design factor that cuts across all application program interfaces, including REST APIs.
API documentation is a reference document, like a technical manual, that outlines how to use an API. It contains information about the API’s services, the endpoints it integrates, operations that these endpoints support, the signature that the operation understands, and the API returns’ responses for a request. Documentation helps reveal an API code’s meaning and how developers can use it to achieve a task.
It is the marketing tool for an API, giving a glimpse into what users can expect within the interface before diving into it.
API designers get help from certain development templates and tools to create excellent documents. There are important data that is included in the API documentation. REST API Documentation should contain the following information:
- The Authentications required for each request.
- The root path for the REST API version.
- The HTTP methods that can be used with each endpoint.
- Explanation of optional and mandatory request data.
- The meaning of each status code.
- The expected data for each request and the most present responses.
- Examples of request and response data.
- Other helpful documentation that a REST API template could include are:
- Interactive tools for live calls
- Case study guides or a gallery of existing solutions
- Guides and tutorials to getting started and navigating the API
This information, arranged in a clear structure, helps users understand the REST API easily before getting into the software’s codes and structures. REST API documentation is important because of the following reasons.
Benefits of API documentation
- Quick learning for customers and other users. The onboarding time is significantly reduced when there are resources available to show users around the interface.
- Less time is spent handling support calls and queries because users find help and answers to their API documentation questions. For instance, a category for FAQs helps users tackle common problems without calling or emailing the support staff. Increase in users if the documentation provides understanding and enhances ease of use.
- Better user experience. When developers enjoy using a REST API, they recommend this to others, increasing the software’s business popularity.
- Clear, well-structured documentation encourages non-coders and non-developers to use the API and gives them the satisfaction of meeting business goals.
REST API Documentation Template
For REST APIs to produce great documentation, they obtain the help of certain templates that help them generate and structure these documents to understandable forms. There are several REST API documentation templates used by developers as below.
- OpenAPI (Swagger): Previously called Swagger, this is the most popular Open-source documentation template in the market. It aims to meet the challenges of teaching and documenting APIs at the same time. It uses JSON objects to describe API elements.
- RAML: Also known as RESTful API Modelling Language, is a simple way of documenting RESTful APIs. It has a RAML to HTML tool to output documentation based on RAML files.
- API Blueprint: It’s an Open-source documentation template that offers designers an automated way of generating API documents. API Blueprint highly accessible, excelling in the design-first API building philosophy.
Of these three templates, OpenAPI is the industry-standard template for RESTful APIs, gaining momentum of usage in the past few years. There is a large community of support behind this template with a large pool of REST API documentation tools behind it. It is excellent for businesses that do not have a specific choice and want to explore a broader range of functions. Besides, new users have a support system for whenever they are stuck.
REST API Documentation Tools
There are many API documentation tools in the market, with a significant number of these compatible with REST APIs. Here are a few best options;
There is a wide range of swagger tools where this one belongs, including Swagger Hub, Swagger Enterprise, and Swagger Inspector. The features and benefits of Swagger UI include is customizability, support of OAS version 3.0 and the old Swagger 2.0, and a wide support community.
This is a premium version of Swagger UI, combining its features with those of Swagger Editor ad other parts of the Swagger group for business enterprise users. Its features include its single-package units, which means users do not need separate software to get complete API documentation. It also allows users to generate documentation during design automatically and offers real-time commenting and tracking collaborative tools.
It is a great Open-source tool for stylish and attractive API documentation and supports OAS 2.0 and 3.0. It offers easy navigation and flexibility.
Its an excellent open-source documentation tool that supports both OAS 2.0 and 3.0. Its documentation is clear even to new users and integrates markdown content from GitHub.
This is an easy-to-use documentation generating tool supporting OAS 2.0 and 3.0 and generating stubs and libraries. Also, the tool can be used extensively, supporting over 50 clint generators. With great community support, this tool boasts a valuable resource as a source of information for starters. OpenAPI Generator converts documentation into HTML or Cwiki formats.
There are many templates and tools that API designers can choose from for the documentation. The examples listed above are just a few examples of a vast pool of options. The choice depends on the developer’s needs, the supporting framework, and the size of the enterprise if it is a business organization. REST APIs or RESTful API is more commonly used; thus, many of the tools and templates outlines here will be compatible.