SendVerifyTemplate.cs

using System;
using Newtonsoft.Json;
using System.Net.Http;
using System.Net;
using System.IO;
using System.Diagnostics;

namespace ConsoleApp15
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            var client = new HttpClient();
            const string BASE_URL = "https://api.nexmo.com";
            const string VERSION = "";
            const string API_KEY = "NEXMO_API_KEY";
            const string API_SECRET = "NEXMO_API_SECRET";
            const string ACTION = "/verify/templates";
            var URL = BASE_URL + VERSION + ACTION + "?api_key=" + API_KEY + "&api_secret=" + API_SECRET;
            var request = new TemplateRequest()
            {
                ActionType = "sms",
                LanguageCode = "en-gb",
                ContactEmail = "foo@bar.com",
                Template = "Your {brand} verification code is ${pin}"
            };
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(URL);
            httpWebRequest.ContentType = "application/json";
            httpWebRequest.Accept = "application/json";
            httpWebRequest.Method = "POST";
            using (var sw = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                var json = JsonConvert.SerializeObject(request);
                sw.Write(json);
            }
            var httpRespone = (HttpWebResponse)httpWebRequest.GetResponse();
            using(var sr = new StreamReader(httpRespone.GetResponseStream()))
            {
                var result = sr.ReadToEnd();
                var response = JsonConvert.DeserializeObject<TemplateResponse>(result);
                Debug.WriteLine(response.AccountId + " " + response.Status + " " + response.Template);
            }

        }

        public class TemplateRequest
        {
            [JsonProperty("action_type")]
            public string ActionType { get; set; }

            [JsonProperty("lg")]
            public string LanguageCode { get; set; }

            [JsonProperty("template")]
            public string Template { get; set; }

            [JsonProperty("tyoe")]
            public string SMSType { get; set; }

            [JsonProperty("welcome_message")]
            public string WelcomeMessage { get; set; }

            [JsonProperty("bye_message")]
            public string ByeMessage { get; set; }

            [JsonProperty("contact_email")]
            public string ContactEmail { get; set; }
        }

        public class TemplateResponse
        {
            [JsonProperty("account_id")]
            public string AccountId { get; set; }

            [JsonProperty("action_type")]
            public string ActionType { get; set; }

            [JsonProperty("bye_message")]
            public string ByeMessage { get; set; }

            [JsonProperty("lg")]
            public string LanguageCode { get; set; }

            [JsonProperty("status")]
            public string Status { get; set; }

            [JsonProperty("template")]
            public string Template { get; set; }

            [JsonProperty("type")]
            public string SmsType { get; set; }

            [JsonProperty("version")]
            public string Version { get; set; }

            [JsonProperty("welcome_message")]
            public string WelcomeMessage { get; set; }
        }
    }
}