We need a new Addon for WHMCS to allow us to sell and provision Google Apps.
AFAIK currently there is no API to provision new domains, only to provision new users on existing domains so this needs to be taken into consideration.
Requirements of Addon are as follows.
1. allow customers to Purchase Google Apps. This will need to alert us to setup domain manually until this can be done via API.
A configurable email template will be used to send customer their Google Apps login details and instructions.
2. allow us to set monthly/yearly pricing per user.
3. Customer can choose whether or not to do a 30 day trial. If they choose to do the 30 day trial, billing will not begin until 30 days later, with any pro rata payments to allow the billing to occur on our normal billing date.
At the end of the trial, if customer has not cancelled, then their Google apps account will be upgraded from trial to full. A notice should be sent to customers before the end of the trial warning them that this will happen unless they cancel.
4. Customer can add/remove users which will update their billing and google apps account accordingly.