Best Practices to Look for in Payment Platform APIs

What are the best practices you should look for in payment platform APIs?

This post discusses the technical best practices you should look for when considering a payment platform API or payment gateway API integration. Of course, the exact requirements for online payment APIs vary depending on many factors, such as your product and the provider you choose, but the below list of questions is a good starting point for assessing the quality and intuitive nature of a payment platform API.

1. Is the API properly semantically constructed?

To promote a smooth experience that’s free of any defects, APIs should be constructed using JSON, and endpoints should end in a noun. If endpoints are published ending in a verb, ambiguity could occur, and things become more likely to break. When verbs are used, they should be limited to the four words that cover all possible scenarios: get, host, put, and delete.

2. Is the API consistent, and does it follow the principle of least astonishment?

The principle of least astonishment proposes that a system should behave in a way that most users would expect. In other words, there shouldn’t be any elements that surprise or astonish users. You should find that each request you make yields the results you would anticipate. You should not have to ask yourself, “Why is this happening?” Payment providers who put in the extra effort during the design phase offer a flawless, commonsense user experience.

3. Is there up-to-date documentation? 

You should expect to have accurate, up-to-date API documentation containing all relevant endpoints. This should also include examples of how to use these endpoints in several programming languages. It’s not enough to only provide this information in javascript; a reputable payment provider will anticipate users’ potential range of needs.

4. Have there been breaking changes in the past?

APIs change over time as software evolves to meet the users’ needs. A good platform is, therefore, never done changing. With that in mind, it’s essential to ensure that as the API does improve, there haven’t been a significant number of issues experienced on the users’ side. Platform enhancements are only beneficial if there are no breaking changes or disruptions in service. These hiccups can create serious frustrations. It’s important that the payment provider design and solidify an API layer in a way that’s future-proof so it doesn’t break as the structure is modified.

5. Does the Payment API use Secure Socket Layer (SSL) Protocol?

For maximum security, API calls should be made over an SSL-encrypted HTTP connection or HTTPS. This more secure protocol ensures that all data is encrypted before being sent between the client and server.

6. Provide Support for Filtering, Sorting, and Pagination

You should be able to easily view and locate data points that are returned on a call. 

Endpoints will often return a lot of data, so it’s important that you can pinpoint data with ease. Be sure that the API allows you to parse through data by:

• Filtering: applying set parameters or criteria to narrow down data
• Sorting: choosing how to display results (e.g., ascending or descending)
• Pagination: viewing results on several separate pages

7. Can you get the data you need from making a call?

The payment platform API should ideally return your requested data with one call. For example, say that you make a call for customers with outstanding balances in the past month. The results should yield a list that’s neither too overwhelming to navigate nor too small to provide the data you need. In other words, you shouldn’t have to sift through a vast amount of data that leads to cumbersome, tedious work. But you shouldn’t have to go back to get more information, either.

8. Does the Payment API handle errors and error responses intuitively?

Developers who code against API platforms, assisted by the public developer documentation, have come to expect a set of standard patterns in how platforms report exceptional situations. API errors, when not handled properly by the platforms, shift the burden to the developers, which is not ideal. Standard error HTTP error codes such as 400, 401, 403, 500, 502, etc., need to be used with the right exceptional context for which they are intended. Standard HTTP error codes must be accompanied by intuitive error messages suggestive enough for the API callers to understand the situation.

9. How fast is the payment API at returning responses to large queries?

The goal of a good portion of publicly exposed APIs of any modern platform is to return data fast. Systems of record (SOR), such as relational databases, often require heavy queries, adding latencies in the API path. The payment API should use a caching layer between the API and SOR to avoid any latency. To avoid this latency, payment providers need to introduce a caching layer between the API and the SOR. When adding a caching layer is not possible for architectural reasons, providers must rely on fetching the data from read-only replicas of SOR for performance reasons. In this situation, the payment provider may have opted for a trade-off of faster data over consistency, and if so, it must be clearly documented.

By taking the time to review these best practices, companies can ensure that they are utilizing a payment platform API that is safe, secure, and reliable. This will help them to provide customers with the best possible experience when making payments. 

Looking for a seamless software PayFac integration? Check out our payment platform API documentation for a payment gateway API example or request a consultation to learn more.