Documenting Your Existing APIs: API Documentation Made Easy with OpenAPI & Swagger

  March 07, 2018

API description formats like OpenAPI (formerly Swagger Specification), RAML, and API Blueprint changed the way teams thought about API documentation — providing a new way to describe the behaviors and attributes of an API. In recent years, the OpenAPI (OAS) has gained the most adoption and is quickly becoming the industry standard for REST API definitions. As OAS has grown in adoption, new tools have continued to emerge to help unlock the power of defining your APIs.

Building great APIs with OAS and Swagger

Swagger is the most widely used tooling ecosystem for developing APIs with the OAS. While the name Swagger is often used interchangeably with the specification — Swagger now represents a collection of open source and pro tools for implementing OAS. Swagger UI is one of the most well-known tools for documenting APIs with OAS. Using Swagger UI — either open source or within the SwaggerHub platform — you can convert your OAS contract into an interactive API console that consumers can use to interact with an API and quickly learn how the API is supposed to behave. Visualize all of your internal APIs so that developers can use upstream and downstream services quickly and easily. SwaggerUI has interactivity built in, so external consumers can also try each resource of an API and get comfortable with it before using it in their code base. In addition to generating documentation, Swagger supports the ability to generate implementation code and SDKs for an API with Swagger Codegen. It can also help deploy your API definition to popular API gateways like AWS, IBM API Connect, Apigee, and Microsoft Azure from within the SwaggerHub platform.

Getting started with OAS and Swagger

While a lot of developers are at ease with designing a brand new API from scratch using the OAS, generating the OAS for existing APIs becomes quite a challenge. Not only does reverse engineering the specification need a lot of work, but there’s also a learning curve involved to get acquainted with the process of generating the OAS from existing developed APIs. Swagger has multiple tools to help with this process, including the popular Swagger Core project for creating the OAS from Java APIs, and our newly introduced online tool called Swagger Inspector, which auto-generates an OAS definition from any API end point. In our newest white paper: Documenting Your Existing APIs: API Documentation Made Easy with OpenAPI & Swagger, we introduce Swagger Inspector and look at different approaches to getting started with OAS and Swagger. We cover:

  • The importance of API documentation
  • API documentation with OpenAPI Specification (OAS)
  • Approaches to creating the OAS
  • Generating OAS for existing APIs with the Swagger Tools
  • Documenting your API in SwaggerHub

Need to generate an OpenAPI definition for an existing set of APIs? Try out Swagger Inspector. Looking to standardize your design and documentation process? Get started with SwaggerHub today.