IT:AD:ASP.NET:WebAPI:HowTo:OData:Install

• Install the OData v4 package into your presentation assembly: Install-Package Microsoft.AspNet.OData (not the OData V3 one: Microsoft.AspNet.WebApi.OData)
• Create a Controller:
  • That inherits from System.Web.OData.ODataController
  • Whose GET method returns an IQueryable or IHttpActionResult
  • Whose class – or specific method – is decorated with using [EnableQuery]

The key part is to inherit from ODataController:

namespace Demo.Controllers
{
    [EnableQuery]
    public class FooController : ODataController
    {
        public IHttpActionResult Get()
        {
            return Ok(FooService.Items.AsQueryable());
        }
    }
}

• http://www.odata.org/blog/how-to-use-web-api-odata-to-build-an-odata-v4-service-without-entity-framework/