DynamicModelBinder.cs

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using Nancy.ModelBinding;

    public class DynamicModelBinder : IModelBinder
    {
        public object Bind(NancyContext context, Type modelType, object instance, BindingConfig configuration, params string[] blackList)
        {
            var data =
                GetDataFields(context);

            var model =
                DynamicDictionary.Create(data);

            return model;
        }

        private static IDictionary<string, object> GetDataFields(NancyContext context)
        {
            return Merge(new IDictionary<string, string>[]
            {
                ConvertDynamicDictionary(context.Request.Form), 
                ConvertDynamicDictionary(context.Request.Query), 
                ConvertDynamicDictionary(context.Parameters)
            });
        }

        private static IDictionary<string, object> Merge(IEnumerable<IDictionary<string, string>> dictionaries)
        {
            var output =
                new Dictionary<string, object>(StringComparer.InvariantCultureIgnoreCase);

            foreach (var dictionary in dictionaries.Where(d => d != null))
            {
                foreach (var kvp in dictionary)
                {
                    if (!output.ContainsKey(kvp.Key))
                    {
                        output.Add(kvp.Key, kvp.Value);
                    }
                }
            }

            return output;
        }

        private static IDictionary<string, string> ConvertDynamicDictionary(DynamicDictionary dictionary)
        {
            return dictionary.GetDynamicMemberNames().ToDictionary(
                    memberName => memberName,
                    memberName => (string)dictionary[memberName]);
        }

        public bool CanBind(Type modelType)
        {
            return modelType == typeof (DynamicDictionary);
        }
    }

gistfile1.txt

Can be invoked using

    http://localhost:40965/dynamic/nancy?age=10&value=test

Which would give you the following output


    {
      "age": "10",
      "value": "test",
      "name": "nancy"
    }

Module.cs

            Get["/dynamic/{name}"] = parameters => {
                var model =
                    this.Bind<DynamicDictionary>();

                return Response.AsJson(model);
            };