API Documentation and its Must-Haves

Sun Dec 12 2021

3 min read

Documentation allows users to understand and connect with your API smoothly. Well constructed documentation ensures a good developer experience, which is critical for increasing the adoption of your API.

Let's learn more about the essential elements of API Documentation.

API Documentation

API Documentation provides complete information needed to consume the API through descriptions, tutorials, examples, and code samples. It is the first thing a developer notices while deciding the API for their project. Proper documentation increases your API's adoption by making it easy to integrate and use.

The documentation should be detailed but not complicated. It is crucial to make it simple, as any confusion may influence the developer to choose another API with better documentation. This is why popular APIs like Stripe, Twilio, GitHub, etc., use interactive and rich documentation.


There is no limit to what kind of content documentation can cover, but these are a few things that must be included in good documentation:

Quick Start Guides

Quick Start Guides streamline the onboarding process. They must be beginner-friendly and may include code samples or example responses.

Authentication Information

APIs can use different ways to authenticate their users. For example, an API key is generally assigned to the users, which they use to make API calls. Document this authentication process to ensure your users’ onboarding process goes smoothly. In some cases, quick start guides also cover the authentication information.

Endpoint Definitions

At the end of the day, an API's purpose is to deliver information; and endpoints are the gateways for this information. A developer can not use your API if you do not explain the endpoints adequately.

Endpoint definitions must cover the following points:

  • Request method to call the endpoint, such as POST, GET, etc.
  • Endpoint URL.
  • Required and optional parameters for the endpoint.
  • Data returned by the endpoint in response.
  • A short non-technical description of what it does and how it relates to other endpoints.

Code Snippets and Requests

To further improve the onboarding process for your API, you can include code snippets in multiple languages. These code snippets show the details other documentation can not and allow users to get started quickly.

RapidAPI Hub which automatically generates code snippets for all APIs in multiple options. They look like this:

In addition to code snippets, you can also include example request bodies. You can specify examples of what an effective request looks like for each endpoint. These examples can help the users debug their requests if they fail.

Example Responses

While working with most APIs, particularly REST APIs, it is unclear what data we can get until we receive the API response. Even then, actual responses can be extensive, and it can be hard to decipher their structure. Good documentation can fix this confusion by adding example responses for each endpoint to show the users what to expect in return.

Recipe-Food-Nutrition API on RapidAPI Hub has a great illustration of an example response: