Add Two-Factor Authentication to Node.js Web Apps

Add Two-Factor Authentication to Node.js Web Apps

In this tutorial you'll see how you can add two-factor authentication (2FA) to your web app using the Nexmo Verify API and Node.js.

In this tutorial you'll see how you can add two-factor authentication (2FA) to your web app using the Nexmo Verify API and Node.js.

Two-factor authentication (2FA) gets its name from the fact that you require two things to verify your identity. Something you know, like a password, and something you have, like the verification code from your mobile device or physical token.

Adding 2FA to your application does not have to be a difficult chore. This tutorial will cover how to implement 2FA for your web applications and services for an additional layer of security with the help of the Nexmo Verify API. We will be building a simple Koa.js application to understand how the underlying mechanism works. This will make it easier to see how this will fit into your own existing projects, even if you are not using Koa.js.

You would start off with a login page that asks your user for a mobile phone number. Upon submission, they would be asked to input a verification code that gets sent to their mobile phone number via SMS. Once that’s sorted, they can access the application.

  • A basic understanding of Javascript
  • Node.js installed on your machine
  • A Nexmo account (for your API credentials)

This tutorial will take you through the process from scratch. If you’d like to see the finished code, you can clone the git repository for this project. We also have a Glitch version, which has a more over-the-top design, and you can remix it as well. Note that they are slight differences for the Glitch implementation to cater for how projects are hosted on the platform.

Starting a Koa.js project from scratch

Create a project folder on your local machine, then run the following command to set up a new Node.js project.

npm init

This will trigger a series of prompts that will generate your package.jsonfile. You can choose to leave the answers blank to use the default values if you wish.

Next, install Koa.js. Do note that Koa requires node v7.6.0 or higher for ES2015 and async function support.

npm init

Create a package.json file in your project folder.

npm init

Paste the following code into your newly created file.

npm init

Run the package.json file.

npm init

If you navigate to package.json from your browser, you should see an empty page with the text, “Hello Unicorn 🦄”.

You should also install dotenv, which allows you to load environment variables stored in a package.json file into package.json.

npm init

And now you can create the package.json file and it should contain at least the following variables:

npm init

To access environment variables, you’ll have to require it, ideally at the top of your package.json file.

npm init

If you haven’t signed up for a Nexmo account yet, now is a pretty good time to do it. Once you’ve logged into the dashboard, your API credentials should be the first thing you see. Be sure to enclose both your key and secret with quotes.

Project structure

Right now, your project would probably only have a package.json, a package.json file and a package.json file. Let’s set up the project structure so you can have a basic frontend for users to interact with.

npm init

With that, you’ll have to make some tweaks to the package.json file to serve the package.json file and related assets, instead of simply a line of text. Koa.js is a fairly barebones framework, so any additional functionalities for routing or serving static assets need to be installed separately. Here is the list of additional modules and their uses:

  • package.json for serving static assets
  • package.json for handling data sent over via POST requests
  • package.json for routing
  • package.json to render templates

This example also makes use of Nunjucks to render template files. The Nexmo Verify API will be used to trigger the verification code via SMS, so you will need to install Nexmo’s Node.js client library as well.

npm init

Serving static assets and HTML files

To allow the application to serve static assets. like stylesheets and client-side Javascript, out of the /public folder, you can add the following to the package.json file:

npm init

To serve HTML files out of the /views folder, you can make use of package.json, which provides a package.json function. The templating engine used in this example is Nunjucks, but you are free to choose whichever templating engine works best for you.

npm init

The next thing to set up would be some basic routes for serving your application pages.

npm init

For this example, you will need 3 pages, the package.json as the main landing page, package.json for users to input their verification code and package.jsonto show if the verification was successful or not.

The structure of the web form is fairly straightforward, and you are free to spruce it up with CSS however you wish.

npm init

This form will post the user inputs to the package.json route and you can use the phone number in the input to trigger the verification code request. A similar form can be used for the other 2 routes for package.json and package.json as well.

npm init

Handling user inputs

Then, for handling user inputs via web forms, you will need some routes to handle package.json requests as well. Do make sure to declare package.json before any of the routes.

npm init

Now that you’re able to receive your user’s phone number, you will need to use the Verify API to send a PIN code to it. Initialise a new Nexmo instance with your credentials.

npm init

There are 3 functions we need to take care of. The first one is to trigger the verification code with the package.json function. It involves the user’s phone number, and a string for the brand name which will be displayed to the user as the sender.

npm init

Once your user received the PIN code via SMS, they will have to submit it to the package.json function, so it can be verified. You will notice a package.json parameter. This value is obtained when the PIN code was successfully triggered. There are a number of ways to pass the request ID into the package.json function, and this example makes use of a hidden field in the check form.

npm init

The last function gives your user the option to cancel the verification if they changed their mind. It uses the package.json function, and again, requires the request ID generated from triggering the PIN code and a string value of package.json.

npm init

Now you need to make use of these 3 functions in the routes we specified earlier, starting with the one for triggering the verification code first.

npm init

The package.json will look something like this:

npm init

You can grab that phone number and pass it to the package.json function. As long as it is a valid phone number, the verification code will be fired off and you will receive a response containing a package.json and package.json.

npm init

From there, you can send the request ID over to the frontend for use when the user enters the verification code.

When your user submits the correct PIN, you will need to plug both the PIN and the request ID into the package.json function.

npm init

Again, both those values can be obtained from the package.json and if the PIN is validated to be correct, you will receive a response that looks like this:

npm init

You can then make use of the status code to determine what message you would like to display to your user. This example uses Nunjucks, so the markup on the results page could look something like this:

npm init

This was a thorough break-down of each part of the code but for a look at how the application looks like in its entirety, do check out the source code on GitHub.

Additional things to take care of

This tutorial is a stripped down version, highlighting only the bits necessary for implementing two-factor authentication. But there are numerous things that have to be taken care of in an actual application. One of the most important is error handling. The Verify API returns a status value of package.json for successful queries, but any other value indicates an error.

These errors should be handled and the user interface on the frontend should reflect any potential errors preventing sucessful verification. It might also be a good idea to implement some sort of frontend validation, or even utilise Nexmo’s Number Insight API to ensure only valid phone numbers are passed to the Verify API.


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How to Use Express.js, Node.js and MongoDB.js

How to Use Express.js, Node.js and MongoDB.js

In this post, I will show you how to use Express.js, Node.js and MongoDB.js. We will be creating a very simple Node application, that will allow users to input data that they want to store in a MongoDB database. It will also show all items that have been entered into the database.

In this post, I will show you how to use Express.js, Node.js and MongoDB.js. We will be creating a very simple Node application, that will allow users to input data that they want to store in a MongoDB database. It will also show all items that have been entered into the database.

Creating a Node Application

To get started I would recommend creating a new database that will contain our application. For this demo I am creating a directory called node-demo. After creating the directory you will need to change into that directory.

mkdir node-demo
cd node-demo

Once we are in the directory we will need to create an application and we can do this by running the command
npm init

This will ask you a series of questions. Here are the answers I gave to the prompts.

The first step is to create a file that will contain our code for our Node.js server.

touch app.js

In our app.js we are going to add the following code to build a very simple Node.js Application.

var express = require("express");
var app = express();
var port = 3000;
app.get("/", (req, res) => {
  res.send("Hello World");
app.listen(port, () => {
  console.log("Server listening on port " + port);

What the code does is require the express.js application. It then creates app by calling express. We define our port to be 3000.

The app.use line will listen to requests from the browser and will return the text “Hello World” back to the browser.

The last line actually starts the server and tells it to listen on port 3000.

Installing Express

Our app.js required the Express.js module. We need to install express in order for this to work properly. Go to your terminal and enter this command.

npm install express --save

This command will install the express module into our package.json. The module is installed as a dependency in our package.json as shown below.

To test our application you can go to the terminal and enter the command

node app.js

Open up a browser and navigate to the url http://localhost:3000

You will see the following in your browser

Creating Website to Save Data to MongoDB Database

Instead of showing the text “Hello World” when people view your application, what we want to do is to show a place for user to save data to the database.

We are going to allow users to enter a first name and a last name that we will be saving in the database.

To do this we will need to create a basic HTML file. In your terminal enter the following command to create an index.html file.

touch index.html

In our index.html file we will be creating an input filed where users can input data that they want to have stored in the database. We will also need a button for users to click on that will add the data to the database.

Here is what our index.html file looks like.

<!DOCTYPE html>
    <title>Intro to Node and MongoDB<title>

    <h1>Into to Node and MongoDB<&#47;h1>
    <form method="post" action="/addname">
      <label>Enter Your Name<&#47;label><br>
      <input type="text" name="firstName" placeholder="Enter first name..." required>
      <input type="text" name="lastName" placeholder="Enter last name..." required>
      <input type="submit" value="Add Name">

If you are familiar with HTML, you will not find anything unusual in our code for our index.html file. We are creating a form where users can input their first name and last name and then click an “Add Name” button.

The form will do a post call to the /addname endpoint. We will be talking about endpoints and post later in this tutorial.

Displaying our Website to Users

We were previously displaying the text “Hello World” to users when they visited our website. Now we want to display our html file that we created. To do this we will need to change the app.use line our our app.js file.

We will be using the sendFile command to show the index.html file. We will need to tell the server exactly where to find the index.html file. We can do that by using a node global call __dirname. The __dirname will provide the current directly where the command was run. We will then append the path to our index.html file.

The app.use lines will need to be changed to
app.use("/", (req, res) => {   res.sendFile(__dirname + "/index.html"); });

Once you have saved your app.js file, we can test it by going to terminal and running node app.js

Open your browser and navigate to “http://localhost:3000”. You will see the following

Connecting to the Database

Now we need to add our database to the application. We will be connecting to a MongoDB database. I am assuming that you already have MongoDB installed and running on your computer.

To connect to the MongoDB database we are going to use a module called Mongoose. We will need to install mongoose module just like we did with express. Go to your terminal and enter the following command.
npm install mongoose --save

This will install the mongoose model and add it as a dependency in our package.json.

Connecting to the Database

Now that we have the mongoose module installed, we need to connect to the database in our app.js file. MongoDB, by default, runs on port 27017. You connect to the database by telling it the location of the database and the name of the database.

In our app.js file after the line for the port and before the app.use line, enter the following two lines to get access to mongoose and to connect to the database. For the database, I am going to use “node-demo”.

var mongoose = require("mongoose"); mongoose.Promise = global.Promise; mongoose.connect("mongodb://localhost:27017/node-demo");

Creating a Database Schema

Once the user enters data in the input field and clicks the add button, we want the contents of the input field to be stored in the database. In order to know the format of the data in the database, we need to have a Schema.

For this tutorial, we will need a very simple Schema that has only two fields. I am going to call the field firstName and lastName. The data stored in both fields will be a String.

After connecting to the database in our app.js we need to define our Schema. Here are the lines you need to add to the app.js.
var nameSchema = new mongoose.Schema({   firstName: String,   lastNameName: String });

Once we have built our Schema, we need to create a model from it. I am going to call my model “DataInput”. Here is the line you will add next to create our mode.
var User = mongoose.model("User", nameSchema);

Creating RESTful API

Now that we have a connection to our database, we need to create the mechanism by which data will be added to the database. This is done through our REST API. We will need to create an endpoint that will be used to send data to our server. Once the server receives this data then it will store the data in the database.

An endpoint is a route that our server will be listening to to get data from the browser. We already have one route that we have created already in the application and that is the route that is listening at the endpoint “/” which is the homepage of our application.

HTTP Verbs in a REST API

The communication between the client(the browser) and the server is done through an HTTP verb. The most common HTTP verbs are

The following table explains what each HTTP verb does.

HTTP Verb Operation
GET Read
POST Create
PUT Update

As you can see from these verbs, they form the basis of CRUD operations that I talked about previously.

Building a CRUD endpoint

If you remember, the form in our index.html file used a post method to call this endpoint. We will now create this endpoint.

In our previous endpoint we used a “GET” http verb to display the index.html file. We are going to do something very similar but instead of using “GET”, we are going to use “POST”. To get started this is what the framework of our endpoint will look like."/addname", (req, res) => {
Express Middleware

To fill out the contents of our endpoint, we want to store the firstName and lastName entered by the user into the database. The values for firstName and lastName are in the body of the request that we send to the server. We want to capture that data, convert it to JSON and store it into the database.

Express.js version 4 removed all middleware. To parse the data in the body we will need to add middleware into our application to provide this functionality. We will be using the body-parser module. We need to install it, so in your terminal window enter the following command.

npm install body-parser --save

Once it is installed, we will need to require this module and configure it. The configuration will allow us to pass the data for firstName and lastName in the body to the server. It can also convert that data into JSON format. This will be handy because we can take this formatted data and save it directly into our database.

To add the body-parser middleware to our application and configure it, we can add the following lines directly after the line that sets our port.

var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
Saving data to database

Mongoose provides a save function that will take a JSON object and store it in the database. Our body-parser middleware, will convert the user’s input into the JSON format for us.

To save the data into the database, we need to create a new instance of our model that we created early. We will pass into this instance the user’s input. Once we have it then we just need to enter the command “save”.

Mongoose will return a promise on a save to the database. A promise is what is returned when the save to the database completes. This save will either finish successfully or it will fail. A promise provides two methods that will handle both of these scenarios.

If this save to the database was successful it will return to the .then segment of the promise. In this case we want to send text back the user to let them know the data was saved to the database.

If it fails it will return to the .catch segment of the promise. In this case, we want to send text back to the user telling them the data was not saved to the database. It is best practice to also change the statusCode that is returned from the default 200 to a 400. A 400 statusCode signifies that the operation failed.

Now putting all of this together here is what our final endpoint will look like."/addname", (req, res) => {
  var myData = new User(req.body);
    .then(item => {
      res.send("item saved to database");
    .catch(err => {
      res.status(400).send("unable to save to database");
Testing our code

Save your code. Go to your terminal and enter the command node app.js to start our server. Open up your browser and navigate to the URL “http://localhost:3000”. You will see our index.html file displayed to you.

Make sure you have mongo running.

Enter your first name and last name in the input fields and then click the “Add Name” button. You should get back text that says the name has been saved to the database like below.

Access to Code

The final version of the code is available in my Github repo. To access the code click here. Thank you for reading !

Node.js for Beginners - Learn Node.js from Scratch (Step by Step)

Node.js for Beginners - Learn Node.js from Scratch (Step by Step)

Node.js for Beginners - Learn Node.js from Scratch (Step by Step) - Learn the basics of Node.js. This Node.js tutorial will guide you step by step so that you will learn basics and theory of every part. Learn to use Node.js like a professional. You’ll learn: Basic Of Node, Modules, NPM In Node, Event, Email, Uploading File, Advance Of Node.

Node.js for Beginners

Learn Node.js from Scratch (Step by Step)

Welcome to my course "Node.js for Beginners - Learn Node.js from Scratch". This course will guide you step by step so that you will learn basics and theory of every part. This course contain hands on example so that you can understand coding in Node.js better. If you have no previous knowledge or experience in Node.js, you will like that the course begins with Node.js basics. otherwise if you have few experience in programming in Node.js, this course can help you learn some new information . This course contain hands on practical examples without neglecting theory and basics. Learn to use Node.js like a professional. This comprehensive course will allow to work on the real world as an expert!
What you’ll learn:

  • Basic Of Node
  • Modules
  • NPM In Node
  • Event
  • Email
  • Uploading File
  • Advance Of Node

Top 7 Most Popular Node.js Frameworks You Should Know

Top 7 Most Popular Node.js Frameworks You Should Know

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser. In this post, you'll see top 7 of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser.

One of the main advantages of Node is that it enables developers to use JavaScript on both the front-end and the back-end of an application. This not only makes the source code of any app cleaner and more consistent, but it significantly speeds up app development too, as developers only need to use one language.

Node is fast, scalable, and easy to get started with. Its default package manager is npm, which means it also sports the largest ecosystem of open-source libraries. Node is used by companies such as NASA, Uber, Netflix, and Walmart.

But Node doesn't come alone. It comes with a plethora of frameworks. A Node framework can be pictured as the external scaffolding that you can build your app in. These frameworks are built on top of Node and extend the technology's functionality, mostly by making apps easier to prototype and develop, while also making them faster and more scalable.

Below are 7of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).


With over 43,000 GitHub stars, Express is the most popular Node framework. It brands itself as a fast, unopinionated, and minimalist framework. Express acts as middleware: it helps set up and configure routes to send and receive requests between the front-end and the database of an app.

Express provides lightweight, powerful tools for HTTP servers. It's a great framework for single-page apps, websites, hybrids, or public HTTP APIs. It supports over fourteen different template engines, so developers aren't forced into any specific ORM.


Meteor is a full-stack JavaScript platform. It allows developers to build real-time web apps, i.e. apps where code changes are pushed to all browsers and devices in real-time. Additionally, servers send data over the wire, instead of HTML. The client renders the data.

The project has over 41,000 GitHub stars and is built to power large projects. Meteor is used by companies such as Mazda, Honeywell, Qualcomm, and IKEA. It has excellent documentation and a strong community behind it.


Koa is built by the same team that built Express. It uses ES6 methods that allow developers to work without callbacks. Developers also have more control over error-handling. Koa has no middleware within its core, which means that developers have more control over configuration, but which means that traditional Node middleware (e.g. req, res, next) won't work with Koa.

Koa already has over 26,000 GitHub stars. The Express developers built Koa because they wanted a lighter framework that was more expressive and more robust than Express. You can find out more about the differences between Koa and Express here.


Sails is a real-time, MVC framework for Node that's built on Express. It supports auto-generated REST APIs and comes with an easy WebSocket integration.

The project has over 20,000 stars on GitHub and is compatible with almost all databases (MySQL, MongoDB, PostgreSQL, Redis). It's also compatible with most front-end technologies (Angular, iOS, Android, React, and even Windows Phone).


Nest has over 15,000 GitHub stars. It uses progressive JavaScript and is built with TypeScript, which means it comes with strong typing. It combines elements of object-oriented programming, functional programming, and functional reactive programming.

Nest is packaged in such a way it serves as a complete development kit for writing enterprise-level apps. The framework uses Express, but is compatible with a wide range of other libraries.


LoopBack is a framework that allows developers to quickly create REST APIs. It has an easy-to-use CLI wizard and allows developers to create models either on their schema or dynamically. It also has a built-in API explorer.

LoopBack has over 12,000 GitHub stars and is used by companies such as GoDaddy, Symantec, and the Bank of America. It's compatible with many REST services and a wide variety of databases (MongoDB, Oracle, MySQL, PostgreSQL).


Similar to Express, hapi serves data by intermediating between server-side and client-side. As such, it's can serve as a substitute for Express. Hapi allows developers to focus on writing reusable app logic in a modular and prescriptive fashion.

The project has over 11,000 GitHub stars. It has built-in support for input validation, caching, authentication, and more. Hapi was originally developed to handle all of Walmart's mobile traffic during Black Friday.