C# Send A SMS Text Message Programmatically Using Clickatell HTTP API

I would start off by heading here to better understand the Clickatell HTTP API: https://www.clickatell.com/apis-scripts/apis/http-s/. If you are interested they allow you 10 free text messages to try it out before you buy a package. Just sign up for an account and create your HTTP API and use your information to populate the snippet below.

For a particular project I am using this API to send out texts for verification purposes. I am using my method inside of a web service to send the information about a user as well as their pre-generated pin. Of course it is a lot different in my project but I am providing the bare bones below.

If you are a skimmer and you skipped reading anything I said above then here you go:

Code for MyWebRequest class:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Net;
using System.IO;
using System.Text;
using System.Configuration;

namespace CustomWebServices
public class MyWebRequest
private WebRequest request;
private Stream dataStream;

private string status;

public String Status
return status;
status = value;

public MyWebRequest(string url)
// Create a request using a URL that can receive a post.

request = WebRequest.Create(url);

public MyWebRequest(string url, string method)
: this(url)

if (method.Equals("GET") || method.Equals("POST"))
// Set the Method property of the request to POST.
request.Method = method;
throw new Exception("Invalid Method Type");

public MyWebRequest(string url, string method, string data)
: this(url, method)

// Create POST data and convert it to a byte array.
string postData = data;
byte[] byteArray = Encoding.UTF8.GetBytes(postData);

// Set the ContentType property of the WebRequest.
request.ContentType = "application/x-www-form-urlencoded";

// Set the ContentLength property of the WebRequest.
request.ContentLength = byteArray.Length;

// Get the request stream.
dataStream = request.GetRequestStream();

// Write the data to the request stream.
dataStream.Write(byteArray, 0, byteArray.Length);

// Close the Stream object.


public string GetResponse()
// Get the original response.
WebResponse response = request.GetResponse();

this.Status = ((HttpWebResponse)response).StatusDescription;

// Get the stream containing all content returned by the requested server.
dataStream = response.GetResponseStream();

// Open the stream using a StreamReader for easy access.
StreamReader reader = new StreamReader(dataStream);

// Read the content fully up to the end.
string responseFromServer = reader.ReadToEnd();

// Clean up the streams.

return responseFromServer;

And now the code for the method itself:

public string SendText(string mobile, string pin)
// Make sure to add the country code to ensure the text goes through
string phoneCheck = "";
if (mobile.Length == 10)
phoneCheck = "1" + mobile;
// Clickatell settings
string textmessage = "Your verification pin is " + pin;
string parameters = "";
parameters = "user=yourclickatellusername";
parameters = parameters + "&password=yourclickatellpassword";
parameters = parameters + "&api_id=youruniqueclickatellhttpapiid";
parameters = parameters + "&to=" + phoneCheck;
parameters = parameters + "&text=" + textmessage;
parameters = parameters + "&mo=1";
parameters = parameters + "&from=15558675309";
MyWebRequest myRequest = new MyWebRequest("<a href="http://api.clickatell.com/http/sendmsg">http://api.clickatell.com/http/sendmsg</a>", "POST", parameters);
} // SendText

* Note: If you put this call on a server that will require a proxy then add it to your MyWebRequest class


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