DHC allows you to run tests manually, but it also enables you to automate your tests.
Where test automation is concerned, DHC provides a Maven plugin that will allow you to run your tests locally while you're building your API, by integrating your test's execution in your project build with Maven.
As your tests run in a Maven plugin, you can run them in Jenkins for continuous integration. This means that in case of a modification, your tests will be automatically executed again to check that nothing has been broken.
Jenkins will display the test reports generated by the Maven plugin as unit tests.
What you can also do from Jenkins is run tests on your API in production at regular intervals which allows you to perform API monitoring pretty easily.
You may also be interested in checking out the following screencast: