Modules

Extend WHMCS functionality by creating a module.

API

Perform actions in WHMCS from your own Apps

Hooks

Tie into events as they occur inside WHMCS.

Templates

Design and develop custom themes.

App Store

Find out How it Works and How to Submit a Listing.

Reference Docs

The Template Syntax and Internal Class references will help.

Check out the Getting Started guide and find answers to common questions.