How to Write API Documentation: Examples and Best Practices
Developer experience is crucial when it comes to API and product adoption. One way to boost that experience is to write well-designed and easy-to-follow documentation. API documentation is important because it increases understanding and adoption in a way that speaks developers’ language. Developers can see how the API works and make their own decisions, rather than having to sit through sales pitches with static demos and slide decks.
Well-written API documentation means developers can get up to speed more quickly and removes the friction between them and your API. Onboarding times and support queries decrease and product satisfaction increases.
Below we’ll explain how to write API documentation that increases developer satisfaction and improves the developer experience and provide examples of companies that have already written successful documentation.
Keep it Simple, But Don’t Skimp on Detail
Keep your API documentation as simple and relevant as possible so you don’t waste developers’ time. Make sure the language is straightforward and free of jargon and concisely explains how your API works. Don’t make API implementation any more difficult than it needs to be. Remember to eliminate any sales pitches in the documentation so developers don’t feel like you’re pushing the hard sell.
While you want to keep your documentation simple and straightforward, you also need to include enough detail to ensure your target audience feels comfortable installing and using your API. Don’t assume a knowledge or skill level that your users may not have and do not include important information they need to get the most out of your API. Adding a lot of relevant detail will also appeal to technically-minded customers and persuade them your software is well-supported. Include details on your API lifecycle and comprehensively document all functionality.
Provide Use Case Examples
Developers want to see how your API works in practice. They want to know how integrations work and how to debug these integrations. They need to understand what happens when a user makes a call and what happens when this call fails. Your documentation needs to include examples of all these calls, as well as their responses and the different parameters and error messages you see for API requests. Other useful information to add includes:
- How to get an API key
- How to authenticate requests
- Status codes specific to your API
- HTTP requests
Make sure you include different user cases so developers can work out which one is most closely aligned with what they’ll use your API for. Also include sample code for commonly used programming languages as this will enable developers to follow along as they go through the documentation and show them how your API works. They can better figure out if it does what they need it to.
Make your Documentation Interactive
Developers don’t just want to read about your API in your documentation. That’s not the best way for them to learn how to use it and for the knowledge to stick for long enough that they want to adopt your API. Adding interactive elements to your API documentation provides a better user experience and demonstrates what you mean. Consider adding interactive elements, such as:
- Open-ended and multiple-choice questions
- Quizzes, polls, and surveys
- Community discussion forums
Link to More Resources and Your Community or Forums
No matter how good your documentation is, developers will still need more information or resources to answer all their questions or ensure they are using your API correctly. Include links to self-paced courses where they can learn more about how your API works. Provide access to software sandboxes so they can access hands-on, immersive exercises that remove the friction between developers and your API.
Include links to other relevant tutorials or blogs, as well as to your product community (or external communities) where they can ask other users questions and share or discuss code with their peers.
Keep Documentation Up to Date
Remember to update your documentation as you develop or make any changes to your API. The last thing a developer wants is to find out your API doesn’t do in practice what you promise in your documentation or they can’t find the information or support they need.
Add “update documentation” as a key step in the update process and don’t roll out any developments until you’ve finished the documentation refresh. This process will also help you catch any errors or inconsistencies in previous versions. Name the updated documentation in line with the API update so developers can trust that you’ve revised it.
Monitor the usage of your documentation so you can see which elements are used most often. Use this data to improve your documentation so it better meets the needs of your readers. Encourage developers to provide (positive and negative) feedback on your documentation so you have first-party data on what you need to improve.
Examples of API Documentation
If you’re looking for inspiration or you’re unsure where to start, we’ve provided examples of companies below that have already written stellar API documentation.
Twilio is a leader in the world of API documentation. The company separates its documentation into different use cases. Each section includes quick-start guides to help users get up and running, tutorials, and sample code. They use straightforward language, include links to get more information, and ask for your feedback. There are also lots of sample code examples.
Stripe is well-known for having comprehensive and easy-to-use API documentation. It provides a ton of code snippets through the documentation, with code that is almost ready to go, as well as examples of responses. It’s also well written, with plenty of thought put into the tone and language, which makes it accessible to all levels of developers.
Don’t Gate Your Documentation
One final reminder when it comes to API documentation, don’t hide it behind lengthy sign-up processes where developers have to enter details to access it. Make it freely available and easy to find on your site or via Google so users can quickly evaluate your API.