Conceptual question - Custom Functionality Exposed via Web API

Hi All,

I am looking for a method to extend Dynamics functionality. Could you, please, help me to clarify if my idea is even possible?

The goal - to have my own custom  web service methods available via standard Dynamics API. It would be consumed via Ajax calls from the Web Resources.

Of course, I can have separate web service, integrated with CRM, but I was wondering if it possible to have custom functionality "inside" Dynamics?

I was looking at Plugins, but not sure how is possible to expose custom methods from it. As far as I can understand, it has Execute method, but I need several methods (like Task1, Task2, etc) returning results via API.

Thanks a lot!