IdentityModule.cs

using Microsoft.AspNetCore.Mvc;
using Nancy;
using Nancy.Security;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Anyways.Nancy.API
{
    public class IdentityModule : NancyModule
    {
        public IdentityModule()
        {
            Get("/identity", args => this.Get());
        }

        public object Get()
        {
            try
            {
                this.RequiresAuthentication();

                var claims = new List<Tuple<string, string>>();
                foreach(var c in this.Context.CurrentUser.Claims)
                {
                    claims.Add(new Tuple<string, string>(c.Type, c.Value));
                }
                return claims.ToArray();
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }
    }
}