How Businesses Can Benefit from OpenAPI Specification

This is a guest article by marketing researcher Monica Mendoza

Now that customers are more reliant on digital products and services, entrepreneurs have realized how important it is to invest in business software applications.

One such example is the application programming interface, or API. An API connects two applications through a software intermediary and allows these two software products to exchange data, or “communicate,” with each other. This is possible because of two components in the API:

1. its technical specification that describes the conditions for the data exchange

2. its software interface that’s written to follow that specification.

When these two components work together, they enable a variety of transactions that help businesses fulfill core business processes. These include logins, product searches, online transactions with different payment platforms, and the like.

A capable API developer does the work of writing, documenting, and testing the API’s function calls, the language statements that allow the software to perform unique actions and services. For the API design process to go as smoothly as possible, the API developer needs to have a good toolset at their disposal. Conversely, the savvy entrepreneur knows the difference a good API and API toolset can make. A particularly well-designed API product can boost their engagement with customers and increase their goodwill towards the brand. So, it’s no wonder that partnerships between API developers and client businesses are even stronger now than ever.

That said, it’s important to know that pouring money into API development, just in itself, is not an absolute solution for higher profit. The choice of direction, the tools for API development, and the design approach also matter enourmously. That’s why today’s tech-oriented generation of entrepreneurs should learn not only about APIs, but also the OpenAPI Specification (OAS) format. If you’re a business owner, you benefit when such technology is in place.

Below is a deeper discussion on OpenAPI Specification, its history, and the pros and cons for both API developers and client businesses that will be affected by the use of the description format. Here, you can learn the value of running a complete API toolkit for teams and enterprise and centered on OpenAPI. Lastly, you’ll read some real-life examples about how businesses from several industries are adjusting to become more API-driven. This could help you visualize what an OpenAPI-centric approach could mean for your organization in particular. Hopefully, the additional knowledge will endow your business with an even more modern edge.

OpenAPI Specification: A Review of Basic Concepts

What is an API specification?

First, let’s discuss the importance of a specification to an API’s design. In API design, the specification is meant to standardize the exchange of data between two web services. Developers rely on the specification to understand how exactly the API product is meant to behave and how it is meant to link with other APIs. The specification should allow for a wide range of API-related technologies, regardless of what programming language they are written in, to work together.

With that said, there’s more than one type of API specification that developers can use for their API product. In the early 2000s, the description formats that reigned in the API world were the Service Object Access Protocol (SOAP) and Web API Description Language (WADL). But nowadays, the specification that has become the “industry standard” for REST APIs, or web APIs that use the Representational State Transfer architectural style, is called the OpenAPI Specification.

What is the OpenAPI Specification and what makes it different from other API specifications?

The OpenAPI Specification, or OAS for short, is the brainchild of Tony Tam, the technical cofounder of an online dictionary service called Wordnik. Originally known as the Swagger Specification when created in 2009, it was employed in order to describe Wordnik’s JavaScript Object Notation (JSON) API. The use of the specification helped immensely in the tasks of API documentation, server integration, and code generation within Wordnik.

When other developers began to use the format for their own APIs, Tam sought to formalize the Swagger Specification. It was adopted by information technology company SmartBear Software in 2015; and then in 2017, it was renamed and operationalized by an open-governance group called the OpenAPI Initiative. At the time of writing, OAS is currently on Version 3.0.3, and its source of truth is currently on the software repository GitHub.

Noteworthy characteristics of OAS that set it apart from other specifications are:

  • It offers a standard and language-agnostic interface for describing RESTful APIs.
  • It is both machine readable and interpretable by human readers.
  • Both machines and human consumers of the OAS can understand the capabilities of the service that’s being developed, even without access to the latter’s source code, network traffic, or any additional documentation.

The great advantage that these characteristics afford OAS is the consumer’s ability to both understand and interact with the remote service, even with just a minimal amount of implementation logic at their disposal. Developers who use OAS to describe their REST APIs benefit from even greater clarity in the API design process. This is the steppingstone they need to build adaptable, reliable, and easy-to-use APIs for their clients.

What should developers and client businesses consider about the OpenAPI Specification?

Both developers and client businesses may want to assess the pros and cons of OAS before any decision-making about the format is made. Let’s take a look at the pros and cons of OAS, both on the API development and the business side.

The pros and cons of OAS to API developers

The following are some key advantages that OAS offers to API developers are the following.

Familiar and collaborative API development. In the API industry, it doesn’t pay to be obscure. The more collaborative and unified the industry best practices are, the better it is for actual practitioners. API developers are quite lucky with respect to OAS’s open-source environment. It’s not hard to find up-to-date knowledge about the specification and how to use it. That knowledge also comes from the top mindshare in the API industry, who are more than willing to advance fellow developers’ skills in using the format. That shared productivity counts for a lot in the overall quality of today’s APIs.

High chance of stable implementation. Because it has a strong open-source community and track record behind it, OAS can be implemented in a stable manner into new developers’ API design workflow. OAS is a widely used technology that its backers will be using for a long time, and there are few chances that the specification will be abandoned or merged with other solutions in the near future.

A reliable source of truth and standard for API testing. An API product that hasn’t been tested extensively will spell disaster for the client business and its customers. With that in mind, API developers will want a specification that will help them test better against lags and errors. It helps developers to include OAS in their design workflow. If OAS is the single source of truth for the API, that makes it easier for developers to test all parts of the API system against the specification. That, in turn, increases their chances of delivering an API product of good caliber.

A means to generate API documentation. Lastly, OAS can assist in compiling beautiful and interactive API documentation, or technical content deliverables that detail how the API works. API documentation is something that both developers and API clients urgently need. The API docs can do more than ordinary instruction manuals can—not only acting as a guide to use the API product, they can sell its functionality. Some hosted toolsets out there can auto-generate API docs from existing OpenAPI definitions. If your own API team uses such a toolset, you’ll be able to generate professional-looking documents that increase the viability of the API.

Since no technology is absolutely perfect or foolproof, however, and there are some cons to using OAS that developers shouldn't overlook. Consider the following the most pronounced drawbacks.

Learning curve. OAS is language-agnostic and using the specification doesn’t require the developer to bend over backwards just to code in a different programming language. But that doesn’t mean that it can be learned in an instant. To work proficiently with OAS, developers will still need to adjust their workflows and orient themselves with all resources pertaining to OAS.

Danger of being a band-aid API design solution. One of the biggest mistakes a green developer can make is to assume that OAS is some sort of magic bullet in creating the final product. OAS is not meant to be a band-aid solution to schema-centric API designs, which require more specific remedies. If OAS is used as more of a shortcut approach to understanding the API, then it defeats the purpose of using the specification to release a thorough, well-crafted product.

The pros and cons of OAS to client businesses

Business owners can expect a trickle-down effect from the usage of OAS, which starts from the API developers and ends with the API’s clients. Here are a couple of things that the OAS-driven API design framework can offer client businesses.

Client business can expect well-designed API products. To understand what value the OpenAPI Specification may have for API clients, one should think of them as buyers of model cars, planes, or toy robots. These products come with blueprints, or assembly guides, that explain which part goes where. When the guide produced by the toy company provides clear, straightforward, and thorough assembly instructions for the consumer, it increases their chances of successfully building the model according to the correct specifications. The same effect is in place for OAS as the specification for client APIs. With that same rationale, it puts client businesses on the receiving end of a better API product.

Clients and API developers have a point of reference through the API contract. For any product that requires collaboration between the client and the provider, it’s important for both parties to see eye to eye. There has to be a point of reference for both parties’ understanding of what the product is supposed to achieve, how it works, and what potential issues to expect. In this sense, OAS works as more than just a description format. It provides the basis for an API contract in which everyone is clear about how the API is being designed and how it will perform. That should be of great comfort to client businesses that will want to know if the product is worth their money.

There are, of course, some small caveats that client businesses should consider about OpenAPI Specification, including the following issues.

Takes time to explain the rationale of OpenAPI specification. If OAS is a complex framework for API developers to understand, what about client businesses that aren’t savvy about the technology? API developers shouldn’t forget that discussing OAS with an outsider to the API industry may result in some information overload.

It’s not the only API element clients should learn about. API design is a pretty complex process that involves several aspects. It wouldn’t be good for either the developers or the clients to fixate on OAS while gauging the final performance of the product.

Despite a few drawbacks, OpenAPI Specification is a very promising technology. Many API developers have benefited from incorporating it into their workflow. Business owners who contract with these developers for their API products are, of course, the chief beneficiaries.

How modern businesses benefit from the use of OpenAPI specification: Some real-life examples

Now that you know more about the characteristics of OpenAPI Specification, you might want to see how such a technology would apply in real life. The fact is many businesses from several key industries likely already have OAS-driven APIs in place. These API products are currently helping them fulfill core business functions and serve their market at an even greater capacity.

Here’s a study of how three sectors have welcomed OpenAPI Specification and used OAS-driven APIs for important tasks. You’re sure to recognize the brand names mentioned below.


The eCommerce sector is one of the foremost beneficiaries of OpenAPI technology. OAS is one of the reasons why eCommerce storeowners can scale their services so quickly, and, in so doing, keep their demanding customers happy. The world’s top eCommerce platforms, like BigCommerce, are also very favorable to designing with open-sourced software. That means that most API designers who use OAS for eCommerce APIs rarely have a hard time implementing the design framework.

If you want another example of how OAS is used in big-time eCommerce applications, you need only to look at online bidding site eBay. eBay uses OAS to provide API contracts to interested developers. These contracts serve as a point of reference for new applications that will consume eBay’s APIs. Thus, eCommerce is one of the most exciting areas to design OAS-driven APIs in - with eCommerce entrepreneurs are the ones who benefit.


OpenAPI Specification is also commonly used for APIs in the media industry. It contributes largely to APIs that disseminate valuable information to the public in quick, digestible, and efficient ways. One example of how OAS is used in this context is social media giant Twitter and its developer platform for public APIs. Twitter’s platform is defined using OAS, and it offers a range of public APIs that developers of third-party sites and applications can use for themselves. If you visit a website or a blog that enables you to share information via Twitter, it’s all thanks to this OpenAPI-driven mechanism.

Suffice to say, OAS helps information spread across exclusively digital media, as well as traditional media outlets (like broadsheets) that have digital counterparts. In a world that largely depends on the Internet for its consumption of local and international media, APIs and OAS are definitely here to stay.

Banking and Financial Technology

The banking and fintech sectors serve as interesting case studies for OAS implementation. Before, there was some resistance to using public APIs for banking transactions, as these may have represented a threat to customers’ security. But today’s APIs are built to be even more secure and even better at safeguarding customers’ private information. OAS-driven public APIs have now won the trust of several banks and financial institutions. This is evident in the rise of what’s called “open banking,” or the availability of common banking services that’s made possible with open APIs.

API designers who are working on open banking-related services can turn to OAS in order to implement principles like positive acknowledgment and assertion of truth. These are just some ways that OAS influences modern financial transactions as its influence continues to grow. It may eventually come to the point that most financial services will involve the use of an API. As such, it’s good to have some advanced knowledge about how APIs are being used in banking and finance.

Final Words: using OpenAPI Specification to your advantage

Though OpenAPI Specification isn’t a familiar term to those outside of the API industry, it’s a technology that affects everyone who uses it. The OAS framework offers developers a point of reference for collaborative, creative, and testable API design. This improves their developer experience and, in turn, makes them more capable of delivering a topnotch API product to end users.

To see how OAS has made a mark on the digital landscape, you need only refer to the big brand names mentioned in the section above. OAS can contribute to a client business’s success in incredibly similar ways.

Whether you’re directly involved in the API’s design or the eventual recipient of a complete API product, it helps to know about OpenAPI Specification and other key technologies in the API industry. If it has to do with advancing your craft and keeping up with the times, it’s good to have the extra knowledge on hand. So be sure to stay in the loop for all things  OAS, and always support the hard work done by API developers.

MonicaMonica Mendoza is a writer and marketing researcher based in Manila, Philippines. She spends a lot of time studying how technology continues to transform lifestyles and communities. Outside the office, she keeps herself busy by staying up-to-date with the latest fashion trends and reading about the newest gadgets out on the market.

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