How to Integrate Twilio in C# .NET MVC Project to Send SMS?

Introduction

In today's fast-paced world, where everyone is using tons of websites and applications daily, there are tons of in-app notifications, and all communication is essential. However, those in-app notifications will come only when we open the application. Hence, incorporating SMS capability into projects may significantly improve user engagement and interaction. Twilio, a prominent cloud communications provider, provides a rich API that allows developers to effortlessly send and receive SMS texts, among other communication features.

In this article, we will see how to integrate Twilio to send SMS in a C# MVC project from scratch. So, first, let's create a Twilio account before moving on to the project.

Setting up a Twilio account

To set up a Twilio account, we will first sign up and that's quite easy. If you already have a Twilio account, you can skip step 1 and just follow from step 2.

Step 1. Sign Up in Twilio

Sign up by filling in the basic details on the following link - www.twilio.com. By clicking on "Continue," you will be redirected to another page to verify your email. Once the email is verified, you will need to verify your phone number as well. After that, you will be redirected to another page that will provide a recovery code. Please copy the code and keep it somewhere safe for future use.

Step 2. Log in to Twilio

If you are logging in for the first time, Twilio will ask you a few questions. Just answer them and it will take you to the dashboard which will look like below.

Step 3. Get the Phone Number

Click on the "Get Phone Number" button, and you will receive the number. Before purchasing their plan, your account will be a trial account, and the number given to you will be a trial number.

Step 4. Get SID and Auth Token

In the same screen, you will have a section named "Account Info", where you will following information -Account SID, Auth Token, and My Twilio phone number, which we will be using during development.

Step 5. Verify Phone Numbers

This step is only for trial account users. Since it is a trial account, you will need to verify the numbers, on which you want to send the SMS using your project. You can skip this step if you have purchased a Twilio SMS plan. To verify numbers follow the following steps.

• Click on the verified phone numbers link, you will be redirected to another page.
• Click on the "Add a new caller ID" button in the right corner. A popup will open to add the number.
• Select the country, number, and mode through which you want to verify the number.
• Click verify the number, you will get an OTP on the number you just entered.
• Enter the OTP to verify the number and it will be shown in verified caller IDs.

Now that you have set up the Twilio account. Let's move to the project.

Setting up the project

You can either create a new project or you can integrate Twilio into an existing project. Here, I have created a demo project to integrate Twilio in it and created a Controller named "TwilioIntegrationController". In this controller, I will be writing Twilio-related code. Let's move to the project.

Step 1. Install dependencies

To be able to integrate Twilio in the project, you will need some dependencies, that will help Twilio run.

• Click on Tools.
• Select "Nuget Package Manager".
• Click "Manage Nuget Package for solution".
• In the Browse section, search for Package "Twilio" and install the solution.
• Then, search "Twilio.AspNet.Mvc" and install it too.

Now that you have installed all the necessary dependencies. Let's move to the next step.

Step 2. Code to Send SMS

In the "TwilioIntegrationController", write your code for sending SMS. Here, I am putting all my code in one file. But you should put the necessary code where it should be.

using Microsoft.AspNetCore.Mvc;
using Twilio;
using Twilio.Rest.Api.V2010.Account;

namespace TwilioIntegration.Controllers
{
    public class TwilioIntegrationController : Controller
    {
        [Route("send-SMS")]
        public IActionResult SendSMS()
        {
            string sId = ""; // add Account from Twilio
            string authToken = ""; //add Auth Token from Twilio
            string fromPhoneNumber = "+120*******"; //add Twilio phone number

            TwilioClient.Init(sId, authToken);
            var message = MessageResource.Create(
                body: "Hi, there!!",
                from: new Twilio.Types.PhoneNumber(fromPhoneNumber), 
                to: new Twilio.Types.PhoneNumber("+9175********") //add receiver's phone number
            );
            Console.WriteLine(message.ErrorCode);
            return View(message);
        }
    }
}

Code Explanation

In the above code,

• Add 'using Microsoft.AspNetCore.Mvc;', 'using Twilio;', 'using Twilio.Rest.Api.V2010.Account;' to use Twilio API in the code.
• Then, I have created a method named SendSMS().
• In the method, I created three string variables - sId, authToken, and fromPhoneNumber to store Twilio account SId, Auth Token, and Twilio phone number. I have placed all three in this method, but you should store them in an appsettings file and access them from there.
• Then initiate TwilioClient by passing your account SId and Auth Token, using this lineTwilioClient.Init(sId, authToken);.
• In the next line "MessageResource.Create()" is a method call to create a new SMS message using the Twilio API. It indicates that we are creating a new message resource. We are passing the message body, from phone number and to phone number in it. It creates the message and sends it using the Twilio API.
• In the next line, I have consoled the ErrorCode, if any error occurs during the sending of SMS.
• If you got this exception while executing the method, Permission to send an SMS has not been enabled for the region indicated by the 'To' number, click here to resolve this- solution

Step 3. Call the above method

Call the method that we created earlier, from your code to send SMS from wherever you want in your code and Twilio will send the SMS to the account that you mentioned earlier.

In the above image, you can see the message is sent successfully from the project and the body is the same as we mentioned in our code. But as we are using a trial account, hence, Twilio adds the prefix "Sent from your Twilio trial account-" in all the messages that you will send from your trial account. Hence, for real-life projects, it is better to buy a plan.

Conclusion

In this article, we have seen how to create a Twilio account, set up it, and integrate Twilio with the code in the C# MVC project. By following simple steps to set up a Twilio account and implementing Twilio's API, developers can easily send and receive SMS messages, offering a valuable tool for improving project functionality and user experience.

Like this, you can also integrate Twilio in other languages too. The process is almost similar. You can also use Twilio to send WhatsApp messages and voice messages, etc by simply integrating it into your project. This integration empowers developers to leverage Twilio's robust cloud communication platform to enhance their projects across various programming languages, facilitating effective communication and user engagement.