June 17, 2021

The Critical Role of API Documentation

Documentation is the essential foundation that all technologies need to thrive. Without it, end-users can’t derive the full value of any technology.

You may be thinking, “But nobody ever reads a manual; why would software be any different?” We guarantee that if you read your phone manual, you will find some useful features that you never would have known existed otherwise!

It’s no different with API documentation. It must be done right or else developers won’t be able to work with your APIs efficiently, and it will be challenging to integrate your APIs correctly with application services. And that’s what APIs are all about—connecting application services to each other to facilitate processes like purchasing products and driving business workflows.

API Documentation Basics

API documentation has traditionally been created using collaboration tools, like Confluence or OpenSource Wikis, along with standard text editors. The documentation typically explains how to use and integrate an API and provides information on how to work with the API functions.

For public APIs, good documentation helps drive widespread adoption. Making it easier for companies that you partner with to use your API will influence whether they will select your API over the API of a competitor. For internal APIs, good documentation gives your software developers the ability to quickly and efficiently connect application services.

The faster developers consume APIs developed by other developers, the faster new application services can go to market. And by publishing and promoting API documentation, you can increase the awareness that a new API exists.

Whether you’re trying to get external organizations or internal developers to interact with the API, increased awareness is a good thing!

The documentation will also reduce your support costs, particularly as developer team members come and go. It will be easier for new developers to see how the API is constructed and how to maintain it so that it continues working well as updates are applied.

API Documentation Technical Tips

API documentation tools come in a wide variety. These include free open source software and licensed software. You can also generate API references within API management suites.

There are also hosted developer portals and non-hosted templates. Some solutions provide documentation capabilities within a complete developer center that facilitates collaboration while others provide simple skeleton templates. Each type can be used to generate HTML and CSS to display API methods, parameters, values, requests, responses, and code samples.

Solid documentation starts with the actual API code. API designers should use descriptive business names and concepts when naming endpoints, parameters, and response models. And as you build out the documentation for an API, keep these technical aspects in mind:

  • Standards. The OpenAPI specification standard will help you generate documentation that can be both human- and machine-readable. It’s language agnostic and enables automated code generation for API endpoints.
  • Authentication. Explain how to secure credentials; including sample authentication code will also help.
  • Error handling. Document how the API communicates error information and how to fix problems.
  • HTTP requests and response details. List content types, status codes, and caching mechanisms.
  • Examples. Include an example of how each call request is made and what the call does.

Also, be sure to document a clear description of every parameter. This includes describing all the possible parameter values—including their types, formatting, and rules.

API Documentation Presentation Best Practices

API documentation isn’t only about the content; it’s also about the presentation. In addition to making sure your API documentation includes all the technical information that internal and external developers will require to interact with an API, it’s important to follow a few best practices in developing your strategy to make sure your audiences can easily digest the information.

Identify Your Audience

The first step is to identify all of your potential audiences and keep them in mind as you design your documentation. The audience may include experienced developers, new developers, internal developers, external developers, or a combination of all four groups. Debuggers may also use the documentation as well as senior IT managers who are scouting APIs for their software development teams.

Decide on Formats

Developers like to learn in different ways, and for some, a quick-start guide works best. It should list the minimum steps to complete key meaningful tasks along with domain information such as expressions and methods. Other developers will prefer a tutorial covering the specific functions of your API. The step descriptions should be concise and avoid jargon. Walkthroughs should cover the smallest amount of steps that lets a user finish a task.

Layout and Navigation

Layout and navigation are other key factors in determining whether your API documentation will be effective. They are essential to the user experience and may determine whether or not they end up using your API. Most good examples of API documentation use a dynamic layout as it makes navigation easier for users than static layouts, especially when looking for specific topics in extensive documentation. Starting with a scalable dynamic layout will also allow you to easily expand your documentation.


A Business Leader’s Guide to APIs

The Value of API Documentation for Your Business

Your efforts to document one of your APIs never quite end. If the documentation falls out of date, and you apply changes to the API, users will get frustrated looking for features that no longer exist or trying to use features that lack documentation. Either of these situations can quickly lead to your API no longer getting the usage you want.

It’s important to keep your API functionality and documentation in sync; automated tools are your best ally so you don’t rely on someone’s memory. The OpenAPI standard can also help to keep your API documentation and implementation in sync since you can validate your API specs against the actual API code your team implemented, thus mitigating the problem of documentation becoming out of date.

It’s also important to ask for feedback every so often. Even if your API does not change, developers who interact with it in the future may provide a fresh perspective you did not consider when first developing the documentation. In this sense, you can strive for continuous improvement.

Doing API documentation right is well worth the effort. You will enable your APIs to transmit data via standard technologies and make things easier for internal developers and developers who create interfaces. Most importantly, you will make it easier for your business to interact efficiently with customers and business partners across your industry.

APIs are a vital component of the products we build at 3Pillar Global. Whether you are struggling with your current APIs, or planning an API strategy, be sure to download the Business Leader's Guide to APIs. To learn how we can help your product development efforts, contact an expert today.