All APIs are not usually created the same. For each specific task, you are likely to get multiple competing APIs. These APIs use different approaches and give varying levels of support and documentation, which should be taken into consideration when choosing API to use.
Customer support is critical as well, we had one of our best experiences with an API when The support team helped us through a customized integration of an appointment booking API tailored to our needs. Here are things you need to consider when choosing API.
You need to check how comprehensive the documentation of the API is. Check that the examples are clear, and parameters are explained properly. It would also help if you got a glimpse of how the API’s implementation will look from the documentation.
You should browse through the API and take a keen look at the parameter and method names. Check that they clearly convey the purpose. They also need to fit your preference in terms of the naming conventions. Some providers nowadays try to be smart and use HTTP verbs and custom headers, which they may not be trivial to program against. This may either be beneficial or a drawback to you, depending on how you view this.
Based on the complexity of a specific API, having ready support for your preferred programming language in the form of example scripts or an SDK can be invaluable. Existing libraries can save you time on debugging and development. The absence of language support raises the onus on having perfect documentation as you will be developing against it.
In the past, XML was the king, as far as the programmatic request data format is concerned. JSON has emerged since then, and it is lighter and an easier alternative to use. Some APIs, however, still use the URL encoded string. Look for your ideal API based on your preferred data format.
You will need to employ request thresholds per API if you go for those with public-facing data. Such limits are used to prevent abuse or motivate people to upgrade your account; however, they add overhead and complexity from the developer’s perspective. You should manage your request rate and ensure you do not hit the API limits. Check that the overhead is right for you, and if there are competing APIs that offer higher limits.