Building an SMS Notification App with Twilio and Node.js: A Step-by-Step Guide

Building an SMS Notification App with Twilio and Node.js: A Step-by-Step Guide

By Jordan Lamoreaux

October 17, 2023

In the world of web development, real-time communication is a valuable asset. SMS notifications are a potent tool for keeping users informed instantly. In this step-by-step guide, we will explore how to create an SMS notification app using Twilio and Node.js, using Koa as our web framework.

When the Playstation 5 was released in 2021, snatching one was no easy feat. I created an app that would scrape specific websites and send me a text message when one became available. In this exercise we will create an API that will trigger an SMS notification to be sent when a request is sent to a specific endpoint.


Before we dive into the technical implementation, I'm assuming you have NodeJS installed and are familiar with using a text editor and command line.

Step 1: Setting Up Your Twilio Account

Before diving into the technical implementation, you need to set up your Twilio account. Here's a step-by-step guide to get you started:

Sign Up

Go to the Twilio website and sign up for an account.

Verify Your Phone Number

As part of the sign-up process, you'll be asked to verify your phone number. This is a security measure.

Access the Console

After creating your account, log in to the Twilio Console. This is where you'll find your Account SID and Auth Token, which you'll use to authenticate your application.

Obtain a Twilio Phone Number

In the Twilio Console, you can purchase a phone number. This number will be the sender for your SMS notifications.

Step 2: Initializing Your Node.js Project

Now that you've set up your Twilio account, it's time to create your Node.js project:

Create a New Directory

Start by creating a new directory for your project.

mkdir sms-app

Navigate to Your Project Directory

Move into your project directory.

cd sms-app

Initialize Your Project

Run `npm init` to kickstart your Node.js project. Follow the prompts to configure your project.

Install Koa and Dependencies

You'll need Koa for this project. Install it and other necessary dependencies:

npm install koa koa-body

Directory Map:

- sms-app/
    - package.json
    - node_modules/

Step 3: Creating the .env File

To keep your Twilio credentials secure, create an .env file for your Node.js project. This is where you'll store your sensitive information. Here's how to create and populate your .env file:

Create the .env File

In the root directory of your project, create a new file named .env.

touch .env

Populate the .env File

Inside the .env file, add your Twilio credentials and phone number as environmental variables.


Directory Map:

- sms-app/
  - package.json
  - node_modules/
  - .env

Step 4: Configuring Twilio in Your Node.js App

With your Twilio credentials and phone number secured, you can configure Twilio in your Node.js project. Here's how:

Create a Configuration File

In your Node.js project, create a configuration file to store your Twilio credentials. You can name this file something like `config.js.`

touch config.js

Configure Twilio

In your config.js file, configure Twilio by requiring the twilio package and using your credentials.

const twilio = require('twilio');
const client = twilio(process.env.TWILIO_ACCOUNT_SID, process.env.TWILIO_AUTH_TOKEN);

Directory Map:

- sms-app/
  - package.json 
  - node_modules/
  - .env
  - config.js

Step 5: Creating Your Koa Application (app.js)

Now, it's time to create your Koa application. This includes setting up routes for sending SMS notifications. Here's how:

  1. Create an app.js File: In the root directory of your project, create a new JavaScript file named app.js.
touch app.js
  1. Add Koa Boilerplate Code: Inside your app.js file, add Koa boilerplate code, including importing Koa and other necessary modules.
const Koa = require('koa');
const bodyParser = require('koa-body'); 

const app = new Koa(); 

// Middleware for parsing JSON and form data

// Routes for sending SMS notifications will go here

Directory Map:

- sms-app/
  - package.json
  - node_modules/
  - .env
  - config.js
  - app.js

Step 6: Setting Up Routes for Sending SMS Notifications

Now that you have your Koa application, set up routes for sending SMS notifications. Here's an example route for sending SMS messages:'/send-sms', async (ctx) => { 
  const { to, body } = ctx.request.body;

  // Use Twilio to send SMS 
  try {
    const message = await client.messages.create({
      from: process.env.TWILIO_PHONE_NUMBER,
    ctx.body = `SMS sent with ID: ${message.sid}`;
  } catch (error) { 
    console.error(`Error sending SMS: ${error.message}`);
    ctx.status = 500;
    ctx.body = 'Failed to send SMS'; 

Step 7: Running Your SMS Notification App

Now that you've configured your SMS notification app and set up routes for sending SMS notifications, it's time to run it:

Start Your Koa Application

If you haven't already started your Koa application, you can do so using the following command:

node app.js

Testing the SMS Notification

You can now test your SMS notification app by sending a POST request to the `/send-sms` endpoint with the recipient's phone number and the message you want to send.


Creating an SMS notification app with Twilio and Node.js, powered by Koa, empowers you to provide users with real-time information and engagement. Whether you are enhancing the user experience of your application or building a real-time alert system, SMS notifications offer a direct and efficient channel of communication. Armed with the right tools and technologies, you can create seamless, real-time messaging experiences for your users.

This guide has provided a thorough, step-by-step overview, from setting up your Twilio account to the technical implementation of SMS notifications. Start your journey in building your own SMS notification app and unlock the endless potential of real-time communication in your projects.