Thank you for your update.
If hosting the Reporting REST service fits your requirements, please consider switching to the WebAPI implementation - Telerik Reporting REST service
. To change the default routes for the service, you can use the details from the How to change the registered by default Telerik Reporting REST Web API routes
Using Telerik Reporting REST WebAPI will allow you to override the service's methods
and add the required attributes where needed. The WebAPI service does not rely on the ASP.NET SEssion, you will only have to configure the cache storage depending on the way it will be hosted - REST Service storage
I hope the provided information is helpful.
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