Overview

Version 6.0 System Requirements
Version 6.0 is a major update to the WHMCS Billing & Automation Platform which introduces new minimum system requirements in order to run it. Be sure to check here first to ensure your web server meets the requirements to run it.

Version 6.0 Release Notes
As with all upgrades, we strongly recommend reading the release notes in full before upgrading to WHMCS 6.0 from an earlier version as there are a number of important changes.

New Client Area Theme

Customising the Six Theme
Everything you need to know about the latest default theme that ships with WHMCS and how to work with and customise it for your needs.

Order Form Templates Compatibility
Some order forms have been modernised and more new order forms are coming in the coming weeks and months. See here for full details.

Dynamic Menus System

Client Area Navigation Menus Cheatsheet
A quick helper guide designed to get you up and running with navbar menu customisations and modifications as quickly as possible.

Client Area Sidebars Cheatsheet
A quick helper guide designed to get you up and running with sidebar customisations and modifications as quickly as possible.

Working with Client Area Navbar and Sidebar Menus
Version 6 introduces a programmatic way to interact with the client area navigation and sidebars through hooks and modules. This article explains in depth how they work, and provides examples of how to manipulate and create your own menus and sidebar panels.

Working With Client Area Home Page Panels
Following on from the Client Area Menus, and using a very similar API, the client area homepage also allows you to interact with them from modules and hooks. This article looks at how they differ from the standard menus, and provides examples for creating your own.

New Features

cPanel Single Sign-On
Everything you need to know about cPanel Single Sign-On, cPanel/WHM version requirements, and how to configure permissions for it.

Domain Namespinning
Domain Namespinning is the name given to the feature that provides intelligent automated suggestions based on the domain or keywords a user enters. This is implemented into both the domain checker and shopping cart domain lookup features. Find out all about it here.

Google No CAPTCHA reCAPTCHA
We've implemented Google's new No CAPTCHA reCAPTCHA for human verification in the New 6.0 Domain Checker. Find out more and how to begin using it here.

Consolidated Plesk Modules
In WHMCS 6.0, we are consolidating the Plesk modules we ship and support. For full details, please refer to the Plesk module documentation.

Custom Crons Directory
All cron task files have been relocated to the crons directory in 6.0. We recommend moving it to a non-public directory above your web root to prevent web based access. This article explains how to do that.

Changelogs

6.0 Changelog
The changelog details all the changes throughout the course of the 6.0 Pre-release Cycles.

Smarty 3.0

Version 6 Template Migration Guide
Provides information on what's changed between Smarty 2.0 and Smarty 3.0, and what changes you may need to make to your custom code, extensions and addons as a result.

Templates and Custom PHP Logic
Discusses best practices for adding your own PHP code and logic within client area pages and template files.

Troubleshooting Blank or Partially Rendered Pages
If you're experiencing a blank page, chances are something is pretty badly wrong. Conflicts or incompatibility with custom and third party modules code are one of the most common causes. This guide explains how to troubleshoot them.

Database Interfaces

Interacting With The Database
In WHMCS 6.0 and later, Models and where Models don't exist, Capsule is the recommended method of database interaction. This article provides further information and examples of how to work with it.

Version 6.0 Database Changes
Version 6.0 introduces a number of database schema changes. If you rely on the database schema in your current code, be sure to look here in case there's anything you need to change.

Developer Resources

Provisioning Module Sample (Updated)
A full sample provisioning module that demonstrates using all of the latest available functionality in WHMCS 6.0.

Working with Module Templates
Version 6.0 introduces a new overrides based system for working with and customising module based templates. This article explains how it works and how to use it.

Hooks Index Listing
A complete categorized and alphabetical listing of all hook points available to utilise in custom hooks, modules and addons.

Class Based API Documentation
Providing documentation of the new Models and Menu related classes that are being made available to developers

Using Models To Interact With The Database
Version 6 introduces a new Database ORM Layer which is recommended for all interaction with the database moving forward. This guide explains what Models exist, and how to work with them.