Registering the serial number

Your license serial number must be provide to the SDK in order to activate it.
This is simply done by calling the InitMootoolsApplication("Your license key"); at the beginning of the application (do not forget to balance with CloseMootoolsApplication at exit).

Saying that, depending on your licence level there is two different cases:

• Perpetual licence The license serial is not-time limited and is always valid for a given version of the SDK.
  You simply have to provide the serial from you Mootools account to the SDK via InitMootoolsApplication.
  This is the most simple case and there is no need to change the serial, unless you move to a major upgrade of the SDK.
  
• Subscription Your serial is valid for whatever SDK version, but is time limited.
  You can compile with any version of the SDK without the need to update your serial number.
  

As the serial number is time-limited, you must take care of the renewal of the subscription because it will not be recognized once subscription expires.
If you hard code the serial, the SDK will refuse it at expiration and you'll get a disruption of the SDK services for your customers.

We highly recommended to get the serial number via a web service and to store it in an encrypted / hidden config file next to the application. You may then update the serial regularly via the same web service.
A simple HTTPS request to a page where your serial is stored would be enough.
Doing that the serial will be valid at any time without the need to recompilate the target software.