5 Must-Have Features for API Documentation Tools
API documentaiton tools are constantly evolving - I should know since I work on
one at Zuplo. There are many hot topics within the space that are getting a lot
of attention, including multi-protocol support,
testing playgrounds, and better support
for agents through llms.txt. I think one of the most useful way to cut through
the noise and find out what really matters to API developers out there is to
just ask them what they are looking for. I chatted with several developers and
engineering leaders to get a better understanding of which API documentation
tooling features matter most to them or have had the biggest impact. Hopefully,
this guide will be helpful in choosing your next API documentation tool.
1. Markdown Support#
Markdown has long been a developer-friendly language for documenting everything from github ReadMes to even APIs now. Although an API endpoint reference is useful as a gateway into your API - supplemental content like common workflows, or details about how to authenticate with the API are often left-out to avoid clutter. Many API documentation tools support writing these guides in markdown, with support for inline code, images, videos, and more to enrich the developer experience. The key to Markdown's popularity is its simplicity. Here's what Rodger Desai, CEO of Prove had to say
Even as the documentation grows, [markdown's] ease of use makes it simple to maintain and manage. It gives me complete control over the process and is a terrific approach to guarantee that the documentation stays effective and user-friendly.
2. Preview Environments#
Another common feature is integration with CI tooling like Github actions to generate a preview of documentation changes before they go live. Often the workflow is that a developer makes a change, opens a PR, and a github action will generate an ephemeral/preview URL where the changes are live. Derek Pankaew, CEO of Listening.com describes why this is useful:
We also look for a tool that supports versioning and ephemeral environment previews. This means each time we push a new branch or release, an instant "preview doc" is generated. It allows our internal teams to test-drive the updated endpoints and check for clarity or typos before the changes go live. Essentially, it's like having a staging site for your documentation, so nothing "breaks" publicly-or confuses external developers-if there's a mistake.
3. Automatic Syncing#
API documentation is not useful if it is out of date. I'd reckon that developers' number one complain about API documentation is that it is out of date, with endpoints no longer working, or parameters no longer being supported. That's why having an API documentation tool that automatically synchronizes with your API implementation is ideal. Many API frameworks like FastAPI or Laravel automatically generate OpenAPI specifications that can be imported into API docs tools like Zudoku. Eamonn Turley uses this feature at his company:
We use Redoc for API documentation - it's open-source and free. Redoc automatically generates interactive docs from our OpenAPI specs, with built-in request/response examples, authentication details, and dark mode support. The tool integrates smoothly with our CI/CD pipeline, enabling automatic doc updates when API specs change.
4. Interactive Playgrounds#
API documentation can no longer be static. With tools like Postman having some form of documentation built-in using collections - most API docs platforms now feature and interactive API playground (essentially a lightweight API client like Postman or Insomnia) where requests can be fired off against the API. Typically, your API credentials are already integrated into the developer portal - making testing seamless. Derek Pankaew had more to say on this:
Stoplight provides an intuitive "Try It Out" feature so developers can run test calls against our staging environment right from the documentation. That hands-on interactivity is crucial to reducing friction for new adopters of our API.
5. Collaboration Support#
The ability to easily collaborate across your team on API documentation is critical at scale. Whether that is through some sort of web UI that breaks up your API into projects each team can manage, or a gitops based approach - updating docs must be a collaborative process. Some use tools like Stoplight to collaborate, like Adrian Iorga -
I use Stoplight for documenting APIs because its design-first approach aligns perfectly with my workflow. It combines powerful collaboration features with intuitive tools, making it ideal for teams or solo developers.
While others simply use the default docs experience built into Postman, like Burak Ozdemir, Founder of Online Alarm Kur
Postman offers API documentation as part of its platform, combining testing and documentation in one place. It's useful because it syncs with collections, so any updates to endpoints or parameters are reflected in the documentation. The ability to create shared workspaces helps teams collaborate efficiently.
Wrapping Up#
Choosing an API documentation tool is not easy, nor is it cheap. Many tools are expensive once you have multiple APIs, or they offer a free/OSS tier that locks away many useful features mentioned above. That's why we created Zudoku to make an API documentation/developer portal that is truly free and 100% Open Source. If you’re looking improve your API documentation and need a gateway that can automatically generate it, get in touch!
