OData protocal defines $format to support different format: http://www.odata.org/documentation/uri-conventions#FormatSystemQueryOption User can use following URL to change the return format to json instead of setting Accept header: http://localhost...

The Issue It's very common to have circular reference in models. For example, the following models shows a bidirection navigation property: 1: public class Category 2: { 3: public Category() 4: { 5: Products = new Collection<Product>...