What is OpenAPI?
As the world is moving towards service-based apps and state-of-the-art microservices, it has become vitally essential for programmers to have a standard interface definition for their RESTful APIs. This is where OpenAPI comes in handy. Also known as OpenAPI specification (OpenAPI) helps developers to simplify application development when multiple protocols, interfaces, and environments are involved. It achieves this by offering a single interface where you can access data.
However, before we go into details about OpenAPI, it is crucial to understand what it is, what it is used for, and why every software developer should use it.
What is OpenAPI Specification?
Formerly known as Swagger Specification, OpenAPI Specification is an open-source format and initiative for designing and creating machine-readable interface files that are utilized in producing, describing, consuming, and visualizing RESTful APIs and web services. The open API file permits software developers to define their API’s essentials, including:
- Present endpoints and each endpoint’s operations
- The input and output operation parameters
- Authentication techniques
The main advantage of using a standard definition is that the third-party users can interact with and understand the service with minimal implementation logic, as long as they are familiar with RESTful APIs basics. API specifications are either written in YAML or JSON, formats that are readable, and easy to learn for both machines and humans.
Is OpenAPI the same as Swagger?
Although the terms OpenAPI and Swagger are used synonymously, they are not the same thing. As mentioned, OpenAPI is a specification that is used to describe, produce, consume, and visualize RESTful APIs and web services. It is powered by the OpenAPI Initiative; an organization comprises of renowned companies such as Microsoft, Google, Capital, Swagger, and IBM.
On the other hand, Swagger is a company that is associated with some of the industry’s most robust tools that are used to implement the OpenAPI specification. It boasts a vast array of software, including open-source, free, and commercial tools, all of which can be utilized in the various stages of the API lifecycle.
Since Swagger was involved in the creation of the original Swagger Specification, its tools are often synonymous with the OpenAPI spec. However, you must understand that other tools can be used to implement OpenAPI specification, apart from the Swagger tools.
What is OpenAPI used for?
Besides helping consumers to comprehend and interact with the remote service without the need for adverse implementation logic, OpenAPI can also be used for other things. These include:
- Generating a server stub for your API
- Generating client libraries for your API in more than 40 languages
- Using spec to join API-related tool with your API
- Create interactive API documentation that allows users to test the API calls straight in the browser.
- It can also be used by code generation tools to generate server SDKs and client CDKs in several programming languages, testing tools, and many other use cases.
Should I use OpenAPI?
Although there have been relentless efforts to developed and allow machine-readable API descriptions, no specification has matched the versatility, comprehensiveness, and support from various vendors like OpenAPI. Therefore, as a developer, you must join the bandwagon of using OpenAPI specifications in your development lifecycle.
And here are the reasons why you should use OpenAPI
Minimizes Errors and Saves Time
Coding is a process that takes time. For this reason, there is a high probability for bugs to creep in, and developers get bored along the process. This may result in various errors and lead to wastage of precious time. However, software developers can escape all this trouble using OpenAPI. This specification boasts top-notch tools that can be used to convert definitions into code, thereby minimizing the effort and time needed to write code.
Allows Collaborative API Design
Design is the most crucial stage in the API development lifecycle. An API is a contract that needs to be followed to the letter by servers, parties, and clients. As such, the API design stage should involve multiple stakeholders to guarantee consistency and efficiency.
Open API definitions come handy in this stage. Using forks, issue trackers, and pull requests, developers can encourage the collaboration of the formalized plain-text documents that reside in repositories such as GitHub. This will ensure that implementation and documentation are linked, and everything is synchronized in all automated continuous integration processes.
Enables You to Generate Seamless and Interactive Documentation
Documentation has become an essential part of modern API development. This because it not only helps developers to understand how to consume APIs but also attracts them to try out your new APIs. Most programmers love interactive documentation that permits them to test API operations immediately after they read about them.
OPenAPI boasts robust tools such as Swagger UI, which offers API documentation with integrated test client. It also features a variety of open source solutions that allow you to generate cutting-edge documentation for your APIs. Using OpenAPI will ensure that the documentation you create will cover your API fully, and list all parameters, methods, and responses correctly.
Allows You to Analyze and Guarantee Quality
OpenAPI allows you to test every part of your system along the API design workflow. This is because OpenAPI definitions are machine-readable and can be used to asses the quality of an API. The specification allows you to conduct manual testing on your API or integrate automated functional and performance tests.
For vast API deployments, you can use an API gateway to asses incoming and outgoing traffic to ascertain whether it complies with the specification. Performing these tests and analysis ensures that your APIs are optimal, thereby lowering the chances of malfunctioning.
Backed by Globally Acclaimed Companies
The OpenAPI specification is backed by some of the world’s leading software-inclined organizations, such as Microsoft, Google, Capital, Swagger, and IBM, which stamps its authority as the standard for designing RESTful APIs. It is used by millions of programmers and enterprises for developing their APIs, be it internal or client-facing.