MongoDb 'provider' for AspNetWebApi-OutputCache
Implementation of IApiOutputCache for MongoDb

Simply create an instance of MongoDbApiOutputCache

MongoDbApiOutputCache takes a MongoDatabase in the ctor, so you can pass this in via IoC.
You can also specify your cache collection name. Default is "cache".

From the AspNetWebApi-OutputCache readme:

You can register your implementation using a handy GlobalConfiguration extension method:

//instance
configuration.CacheOutputConfiguration().RegisterCacheOutputProvider(() => new MyCache());

//singleton
var cache = new MyCache();
configuration.CacheOutputConfiguration().RegisterCacheOutputProvider(() => cache);	

If you prefer CacheOutput to use resolve the cache implementation directly from your dependency injection provider, that's also possible. Simply register your IApiOutputCache implementation in your Web API DI and that's it. Whenever CacheOutput does not find an implementation in the GlobalConiguration, it will fall back to the DI resolver. Example (using Autofac for Web API):

cache = new MyCache();
var builder = new ContainerBuilder();
builder.RegisterInstance(cache);
config.DependencyResolver = new AutofacWebApiDependencyResolver(builder.Build());