Understanding Application Programming Interface (API)

What is API? Although one might know that the letters represent “Application Programming Interface,” appreciating what that means might involve more than simply being able to define what word each letter stands for.

To understand better, one needs to look no further than a bank or even a fast-food restaurant. Very different businesses they might be, but in terms of the layout of the building, they are typically very similar. A back room where the food or money is handled, a front lobby, and a counter that separates the two. The counter is where the front and back interact together.

Software also has a front end, back end, and a “counter.” In API Terminology, we call the counter area the “Interface,” because it’s where software components interact and exchange information. API provides developers with tools for rapid software development. 

APIs are created to integrate with other services and should be evaluated to determine convenience and easy integration. Each API must be flexible and have clear documentation. 

While testing an API, it’s easier to use conventional software testing techniques such as:

• Exploratory testing
• Documentation check
• Boundary value analysis
• Equivalence partitioning
• Usability testing
• Security testing
• Automated testing

The most common errors to look out for include:

• Failure to process erroneous conditions
• Missing or duplicated functionality 
• Difficulties in connecting and receiving an answer from the API 
• API security issues
• Questions on multithreading 
• Incorrect processing of valid values

API Testing evaluates the application programming interface directly to determine everything from its functionality to security. Paying attention to the results lowers the risk of missing bugs in the software, and fewer bugs mean better software.

If you’d like to learn more about Swan can help you develop custom software, contact us.