This post demonstrates how to test RESTful APIs in an automated fashion using PHP by building a testing framework through creative use of two packages - Guzzle and PHPUnit. The resulting tests will be something you can run outside of your API as part of your deployment or CI (Continuous Integration) process. The author explains how to set up the environment, configure PHPUnit to use Guzzle, write tests against an endpoint at httpbin.org, and provides a conclusion on the overall code.