My software development team and I have spent the last couple of months integrating third-party vendors into our application. This involves a lot of time reading API documentation. And, that API documentation can turn integrating a service from a three-day endeavor to a 10-plus-day endeavor depending on its quality. Reading the same docs over and over and still not understanding what is going on is not fun. Here are a few things I’ve found that can make or break your API documentation.
1. Clear Field Definitions
One of the most frustrating aspects of integrating a third-party API is dealing with vague field descriptions in the request or response body. Documentation should explicitly define which fields are required and which are optional. When this information is missing, it often leads to wasted time debugging code — for example, trying to figure out why mapping a response into an object is failing. This issue is especially common when only an example response body is provided instead of a concrete schema that can be directly translated into code. If a field is optional, it should not be labeled as such without context. When it isn’t obvious, the documentation should clearly explain when and why a field is needed or can be omitted.
2. Definitions of API-Specific Concepts
Every API has its own unique terms and concepts that aren’t always obvious to someone using it for the first time. It’s frustrating when documentation assumes you’re already familiar with all the terminology and the inner workings of the service. Without clear explanations, it can be confusing and lead to mistakes, as you might make decisions based on assumptions.
A well-documented API should include a dedicated “guide” section, organized by each unique concept, that explains what the terms mean, how they’re used, and why they matter. Having these explanations in their own section — rather than scattered throughout the documentation — makes it easier to find information quickly. This not only speeds up development but also reduces guesswork, helping to avoid potential pitfalls later on.
3. Code Examples in Multiple Languages
Having code examples in different languages makes it much easier to get started and understand how to work with the API in your preferred language. This is particularly helpful for more complex tasks like verifying a webhook signature or handling authentication. Relying solely on step-by-step instructions without code examples can slow down development, as developers must translate the often ambiguous text into working code, which can take multiple iterations to get right. If code examples are provided, it’s nice for them to be in popular languages like Python, JavaScript, or Java instead of outdated ones — this helps reduce the time spent translating code between languages.
4. Support Channels for Developers
Having clear and accessible support channels can make all the difference when you run into issues or need clarification during API integration. I’ve found that the most helpful method is when a vendor creates a Slack channel with your team’s developers and their technical experts. It makes it easier to have natural conversations and quickly clear up any misunderstandings between questions and responses compared to something like communicating over email. For example, I was able to get help with an endpoint I thought I was using incorrectly. As it turned out, the issue was on their side. Without this method, I would’ve been stuck on the problem indefinitely. I’ve also gotten clarification on concepts that weren’t clear in the documentation.
Parting Thoughts
Good API documentation can save a ton of time and frustration during integration. Clear definitions, helpful code examples, and easy-to-reach support channels make a huge difference in getting things up and running smoothly. If you’re writing API documentation, keeping these points in mind will help the developers using your endpoints — and save you from answering endless questions about confusing details.