Do you perform any exploratory testing on APIs? How do you do it?
Here’s an in-depth version of the reply I gave, with the benefit of links to deeper material.
To begin: application programming interfaces (APIs) are means by which we can use software to send commands to a product to make it do something. We do perform some testing on APIs themselves; interfaces represent one set of dimensions or factors or elements of the product. In a deeper sense, we’re not simply testing the APIs; we’re using them to control and observe the product, so that we can learn lots of things about it.
Now, there’s a problem with the first question: it implies that there is some kind of testing that is not exploratory. But all testing is exploratory. The idea that testing isn’t exploratory comes, in part, from a confusion between demonstrating that a product can work and testing to learn how it does work, and how it might not work.