How to Send WhatsApp API using c#

introduction

In this article, we will create simple examples to send messages via WhatsApp API using c#.

Initially, you must make sure that the RestSharp library last Ver: 108.0.1 is ready and because we will use this library in this article to send messages to the Ultramsg Gateway.

quick Example for WhatsApp API using C#

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";      
            string message = "WhatsApp API on UltraMsg.com works good";
            var url = "https://api.ultramsg.com/" + instanceId  +  "/messages/chat";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("body", message);


            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

When the previous code is executed, and if the message is sent successfully, the response will be like this:

{"sent":"true","message":"ok","id":497}

Send Image

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";      
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/image";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("image", "https://file-example.s3-accelerate.amazonaws.com/images/test.jpg");
            request.AddParameter("caption", "caption text");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Document

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";      
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/document";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("filename", "test.pdf");
            request.AddParameter("document", "https://file-example.s3-accelerate.amazonaws.com/documents/cv.pdf");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Audio

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";    
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/audio";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("audio", "https://file-example.s3-accelerate.amazonaws.com/audio/2.mp3");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Voice

You can Send a ppt audio recording to the phone number or group, But WhatsApp is sensitive to this extension, you need to be in OGG format and the codecs should be the opus, For more information, you can check out this article.

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";    
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/voice";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("audio", "https://file-example.s3-accelerate.amazonaws.com/voice/oog_example.ogg");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Video

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";      
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/video";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("video", "https://file-example.s3-accelerate.amazonaws.com/video/test.mp4");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Link

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";    
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/link";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("link", "https://en.wikipedia.org/wiki/COVID-19");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Contact

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";    
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/contact";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("contact", "[email protected]");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Location

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";  
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/location";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("address", "ABC company \n Sixth floor , office 38");
            request.AddParameter("lat", "25.197197");
            request.AddParameter("lng", "55.2721877");

            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Send Vcard

using System;
using RestSharp;
using System.Threading.Tasks;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";     
        
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/vcard";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("vcard", " BEGIN:VCARD\nVERSION:3.0\nN:lastname;firstname\nFN:firstname lastname\nTEL;TYPE=CELL;waid=14000000001:14000000002\nNICKNAME:nickname\nBDAY:01.01.1987\nX-GENDER:M\nNOTE:note\nADR;TYPE=home:;;;;;;\nADR;TYPE=work_:;;;;;;\nEND:VCARD");
            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Example to send image as Base64 using RestSharp

To send images and documents from a local pc or server, you can convert the files to base64 format and send them easily through the following code:

using System;
using RestSharp;
using System.Threading.Tasks;
using System.IO;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";   

            byte[] AsBytes = File.ReadAllBytes("test.jpeg");
            String AsBase64String = Convert.ToBase64String(AsBytes);
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/image";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("image", AsBase64String);
            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

Example to send document as Base64 using RestSharp

using System;
using RestSharp;
using System.Threading.Tasks;
using System.IO;

namespace test
{
    class Program
    {
        static async Task Main(string[] args)
        {
           
            string instanceId = "instance950"; // your instanceId
            string token = "yourtoken";         //instance Token
            string mobile = "14155552671";   

            byte[] AsBytes = File.ReadAllBytes("test.pdf");
            String AsBase64String = Convert.ToBase64String(AsBytes);
            var url = "https://api.ultramsg.com/" + instanceId  + "/messages/document";
            var client = new RestClient(url);
            var request = new RestRequest(url, Method.Post);
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("token", token);
            request.AddParameter("to", mobile);
            request.AddParameter("filename", "WhatsApp-API.pdf");
            request.AddParameter("document", AsBase64String);
            RestResponse response = await client.ExecuteAsync(request);
            var output = response.Content;
            Console.WriteLine(output);
        }
    }
}

WhatsApp API using C# with WebClient

it’s Not recommended for new work but it’s extremely easy, if you need to do a http request synchronously, WebClient can still be used.

using System;
using System.Collections.Specialized;
using System.Net;
using System.Text;

public class Program
{
    public static void Main()
    {
        using (var wb = new WebClient())
        {
            var data = new NameValueCollection();
            data["token"] = "95041eyo9eqixrsi";
            data["body"] = "WhatsApp API on UltraMsg.com works good";
            data["to"] = "14155552671";

            var response =
                wb
                    .UploadValues("https://api.ultramsg.com/instance950/messages/chat",
                    "POST",
                    data);
            string responseInString = Encoding.UTF8.GetString(response);
            Console.WriteLine (responseInString);
        }

        ///////////
    }
}

Example to send documents as Base64 using c# & WebClient

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Net;
using System.Text;
using System.Web;

public class Program
{
    public static void Main()
    {
        using (var wb = new WebClient())
        {
            byte[] AsBytes = File.ReadAllBytes("1.pdf");
            String AsBase64String = Convert.ToBase64String(AsBytes);
            var data = new NameValueCollection();
            data["token"] = "95041eyo9eqixrsi";
            data["to"] = "14155552671";
            data["document"] = AsBase64String;
            data["filename"] = "a.pdf";
            var response =
                wb
                    .UploadValues("https://api.ultramsg.com/instance950/messages/document",
                    "POST",
                    data);
            string responseInString = Encoding.UTF8.GetString(response);
            Console.WriteLine (responseInString);
        }

        ///////////
    }
}

finally, you can see Full Whatsapp API Documentation and FAQ.