Basic Customization > Windchill Customization Basics > Disallowed Customizations
  
Disallowed Customizations
The following is a list of some customizations that companies implement with Windchill on-premises that are not supported in Windchill+:
Any customization type not listed in Allowed Customizations.
In the server-side code, you do not have access to the following:
File system
Authentication credentials of users
Windchill database
You cannot call out to external systems, for example, with an HTTP client or similar.
Info*Engine
No custom Info*Engine tasks or webjects
No custom Info*Engine web services
REST
No custom REST API’s