How to send SMS with C#

This tutorial teaches you how to use the Telesign C# SDK to send an SMS. The complete sample code for this tutorial is available on GitHub here.

Before you begin

Make sure you have the following before you start:

Authentication credentials: Your Customer ID and API Key. If you need help finding these items, go to the support article How do I find my Customer ID and API Key.
Testing device: A mobile phone on which you can receive SMS.

📘
NOTE:
This tutorial uses the following:

MacOS

.NET Framework v6

dotnet CLI v6.0.400

Please modify accordingly if your developer environment differs from these details.

Set up your project

Follow the Telesign Self-service C# SDK install instructions on GitHub here, incorporating the following details:
- Use sms as the project name.
- Use SendSMS as the solution name.
You should end up in the top-level directory (sms) for your project in the Terminal.

📘
NOTE:
Even if you have installed the C# SDK on your system before, you still need to add the package to this new C# solution.
Enter the top-level directory for the new solution you just created.
```
cd SendSMS
```
Open the file "Program.cs" in your editor.
```
open Program.cs
```

Create code to send an SMS

Import the required namespaces and classes.
```
using System;
using Telesign;
```
Create the basic structure of the script, including the Main function. In the next step, you will begin adding statements to the Main function.
```
namespace SendSMS
{
    class SendSMS
    {
        static void Main(string[] args)
        {

        }
    }
}
```
Define variables in the Main function to store your authentication credentials. For testing purposes, you can just overwrite the default values below or use environment variables (see step 5).
```
string customerId = "FFFFFFFF-EEEE-DDDD-1234-AB1234567890";
string apiKey = "ABC12345yusumoN6BYsBVkh+yRJ5czgsnCehZaOYldPJdmFh6NeX8kunZ2zU1YWaUw/0wV6xfw==";
```
Define a variable to hold the recipient's phone number. For this tutorial, hardcode your testing device's phone number.
```
string phoneNumber = "11234567890";
```

(Optional) Pull authentication credentials from environment variables. Although you might not choose to do so for this tutorial, in your production integration it's a good practice to reference your authentication credentials using environment variables.

if (System.Environment.GetEnvironmentVariable("CUSTOMER_ID") != null) {
    customerId = System.Environment.GetEnvironmentVariable("CUSTOMER_ID");
}

if (System.Environment.GetEnvironmentVariable("API_KEY") != null) {
    apiKey = System.Environment.GetEnvironmentVariable("API_KEY");
}

if (System.Environment.GetEnvironmentVariable("PHONE_NUMBER") != null) {
    phoneNumber = System.Environment.GetEnvironmentVariable("PHONE_NUMBER");
}

Define variables for the message text and the Telesign abbreviation describing the message type. For purposes of this tutorial, use the "ARN" abbreviation (alerts, reminders, and notifications).
```
string message = "Your package has shipped! Follow your delivery at https://vero-finto.com/orders/3456";
string messageType = "ARN";
```
Create a try-catch structure.
```
try
{

}
catch (Exception e)
{
 
}
```
In the try block, add code to instantiate a Telesign messaging client object with your authentication credentials.
```
try
{
    MessagingClient messagingClient = new MessagingClient(customerId, apiKey);
}
```

Next in the try block, add code to make the request and capture the response.

RestClient.TelesignResponse telesignResponse = messagingClient.Message(phoneNumber, message, messageType);

Next in the try block, add code to print the response for debugging purposes. In your production code you would likely remove this.

Console.WriteLine("\nResponse HTTP status:\n" + telesignResponse.StatusCode);
Console.WriteLine("\nResponse body:\n" + telesignResponse.Body);

In the catch block, add code to print any error that might occur.

Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("\nAn exception occured.\nERROR: " + e.Message + "\n");
Console.ResetColor();

After the try-catch structure, add code to allow you to exit the program after it finishes attempting to send the SMS.
```
Console.WriteLine("Press any key to quit.");
Console.ReadKey();

return;
```

Sample code

The complete sample code for this tutorial can be found on GitHub.

Before you begin

📘NOTE:

Set up your project

📘NOTE:

Create code to send an SMS

Sample code

📘
NOTE:

📘
NOTE: