How to Send SMS in Django using Twilio

In this tutorial, we will build a simple Django app with SMS capability to send messages to a phone number once a particular condition is met.

SMS is a good way to send alerts, notifications, and to even authenticate users. There comes a time where by we need SMS functionality in our app. Either to send notifications to clients or even serve as a way of having a "multifactor authentication" feature.

Twillio is a cloud communications platform that allows you to add voice and SMS functionality to your app. It is a paid platform, but for the sake of this tutorial we'll be making use of the trial account.

Prerequisites

To follow along with this tutorial, you'll need Python3 installed on your machine.

A little understanding of Django would help the reader to follow along better.

Table of contents

1. Creating and setting up a new Django project
2. Setting up Twilio
3. Creating a model
4. Configuration
5. Conclusion

Creating and setting up a new Django project

Let's start by creating a new virtual environment.

A virtual environment allows you to create different spaces on your computer, with different set of libraries and versions.

By creating a virtual environment, you'll be able to separate the necessary library installation for a project, without having to install them globally.

Now, create a virtual environment env by running the command below:

$ python -m venv env

Here, we tell Python to create the virtual environment in a folder named env in the current directory.

On creation, activate the virtual environment using the following command:

$ source env/bin/activate

On activating the environment, install Django using the following command:

$ pip install django

Now, let's create a new Django project twilio_proj using:

$ django-admin startproject twilio_proj

Then navigate to the twilio_proj directory and create a Django app.

$ cd twilio_proj
$ django-admin startapp score

Let's add our app to the list of installed apps.

Navigate to the twilio_proj directory and edit the settings.py file.

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'score',
]

Setting up Twilio

To get started with Twilio, we need to sign up on Twilio to create an account and to also get a Twilio number.

Click on the Sign Up button and fill in your details to create an account.

Creating a model

Now lets define a simple class.

In the score directory, edit the models.py file and add the following lines of code:

from django.db import models

#defining a simple class
class Score(models.Model):
    #integer field
    test_result = models.PositiveIntegerField()

    #string representation
    def __str__(self):
        return str(self.test_result)

Now let's register the model of Score in the admin.py file, so that we can modify it in the Django admin section.

from django.contrib import admin
from .models import Score

admin.site.register(Score)

The next step is to migrate our model to the database.

Migrations are Django’s way of propagating changes you make to your models (adding a field, deleting a model, etc.) into your database schema.

Now, let's migrate our model to the database by running the commands below:

$ python manage.py makemigrations # migrating the app and database changes
$ python manage.py migrate        # final migrations

A superuser has the permissions to create, edit, update, and delete data in Django admin.

Create a superuser by running the command below:

$ python manage.py createsuperuser 

Now, we can log in to the admin page.

To login to the admin section, serve the app again and go to http://localhost:8000/admin and log in with your superuser details.

Django admin login page

Django admin page

Now, let's add a score in the Score category to test if its error free.

Click on score, then click Add Score to add a score.

Add score

Configuration

To use Twilio, we need a trial number, account sid, and auth token.

We can find our account-specific configuration credentials on the Dashboard page of the account console as shown below:

Twilio dashboard page

Click on the "Get a trial number" button to get a trial number.

A trial number is a free phone number assigned to you upon sign up by Twilio for testing purposes.

Trial number

Next we need to install the Twilio library using the following command:

$ pip install twilio

Now we need to import the Twilio module in our models.py file:

from twilio.rest import Client

Next, modify your Score class in models.pyto look like the code below:

#defining a simple class
class Score(models.Model):
    #integer field
    test_result = models.PositiveIntegerField()

    #string representation
    def __str__(self):
        return str(self.test_result)

    #save method
    def save(self, *args, **kwargs):
        #if test_result is less than 80 execute this
        if self.test_result < 80:
            #twilio code
            account_sid = 'YOUR_ACCOUNT_SID'
            auth_token = 'YOUR_AUTH_TOKEN'
            client = Client(account_sid, auth_token)

            message = client.messages.create(
                                        body=f'Hi, your test result is {self.test_result}. Great job',
                                        from_='YOUR_TRIAL_NUMBER',
                                        to='VERIFIED_NUMBER' 
                                    )

            print(message.sid)
        return super().save(*args, **kwargs)

With a trial number, we can only send SMS to a Twilio verified number. If we want to send to unverified numbers, you need to purchase a phone number.

For testing purposes, our verified number will be the number we submitted for phone number verification when we created our Twilio account.

Now head over to the django-admin page, add a score less than 80 and you should recieve an SMS.

Twilio SMS

Conclusion

To conclude, we have learned about Twilio. We have also learned how to send SMS from a Django app.

There's still a lot you can achieve with Twilio. Upgrade from the trial version if you are looking to use Twilio in production.

To summarize, we learned how to build a Django app and integrate it with Twilio. We also learned how to send SMS using Twilio from a Django app.

For further learning on how to recieve phone calls, recieve tests, and perform other communication functions using Twilio, check out Twilio docs.

That's all!

Happy coding!

Peer Review Contributions by: Geoffrey Mungai