How to use caching in ASP.NET Web API?

Question

I am using ASP.NET MVC 4 with WEB API

I have the following action, in the action shown below, my service method makes a db call to DoMagic() method and

Answer 1

As already mentioned by OakNinja, output caching via [OutputCache] attributes is currently not supported by the ASP.NET Web API.

However, there are a few open source implementations filling the gap:

Strathweb.CacheOutput

A small library bringing caching options, similar to MVC's "OutputCacheAttribute", to Web API actions.

Github: https://github.com/filipw/Strathweb.CacheOutput
License: Apache v2

CacheCow

An implementation of HTTP Caching in ASP.NET Web API for both client-side and server-side.

Github: https://github.com/aliostad/CacheCow
License: MIT

Note: According to the projects README, the library does not support attribute routing:

Currently CacheCow's attribute setting does not work with Attribute Routing. And I personally think you should not use Attribute Routing... (Source: https://github.com/aliostad/CacheCow/blob/master/README.md)

There is a nice blog post by Scott Hanselmann covering both feature sets.