WHM provides you with a Remote Access Key for allowing 3rd party scripts to access your WHM on Reseller, Virtual, or Dedicated plans. You can allow external scripts to perform a multitude of tasks from account creation, account termination, account suspensions and much more.
In addition to prewritten scripts, if you are familiar with a scripting language such as PHP or Perl, you can custom code your own web-based applications.
A word of warning, use of the Remote Access Key in custom applications requires extensive familiarity with your scripting language of choice.
Luckily, cPanel already provides you with the API needed for communicating with your WHM interface. Documentation regarding cPanel's XML API can be found here:
In combination with your Remote Access Key, cPanel's XML API functions allow you to remotely or automatically perform WHM tasks.
The actual implementation of cPanel's API is beyond the scope of our knowledgebase. However, we have included some great utilities for getting familiar with cPanel's XML API functions.