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Build a Simple Website with React, Axios, and a REST API Built with MongoDB Realm

Published: Aug 18, 2021

  • MongoDB
  • Realm
  • JavaScript
  • ...

By Maxime Beugnet

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REST APIs and React are both very popular technologies in their respective fields and they are also very interesting to combine in a project.

In this blog post, I will show you how we can use a REST API that I created with the help of MongoDB Realm to access my data in my MongoDB Atlas cluster and display the result of the query in a website built with React.

At the end of this tutorial, you will have a basic React project capable of retrieving a list of countries through a REST API and displaying them on a web page.

In the next blog post, I will use this project as a starting point. The list of countries will become a filter for a bunch of charts built with MongoDB Charts that I will be able to import into a website using the MongoDB Charts SDK. The final result will be a COVID-19 dashboard which will be easy to filter by country.


To build this project, you will need a recent version of NodeJS.

Please check that your versions of node, npm, and npx are close to my versions:

1$ node -v
3$ npm -v
5$ npx -v

In the body of this blog post, I will step through how to build this app. If you don't want to follow along, and you prefer to jump to the final project, you can clone this repository from Github:

1git clone
2cd mongodb-realm-react-rest-api
3npm start

#Create a React Application

1npx create-react-app mongodb-realm-react-rest-api
2cd mongodb-realm-react-rest-api
3npm start

The last command should automatically open a new tab in your favorite browser at the address http://localhost:3000, and you should see the default React spinning logo. Before we continue, we can simplify the project by removing all the files we don't need.

1rm -f public/logo* public/manifest.json public/robots.txt src/* yarn.lock

We now have a clean canvas for the next step.

#Install Axios

Axios is a promise-based HTTP client for Node.js and the most famous HTTP client, as far as I know, with currently more than 14 million weekly downloads. We will use it to query our REST API and retrieve the list of countries to display.

1npm i axios

#Checking the REST API

As mentioned in the introduction, the REST API we are going to use in this blog post already exists and was created using MongoDB Realm so it can scale easily and automatically. This REST API exposes metadata from the COVID-19 Open Data Cluster that we made publicly available. Check out this blog post for all the details.

This is the REST API we will use. You can open it in a new tab in your browser or use the curl command:


The result from accessing this REST API is a JSON document that looks like this:

2 _id : "metadata",
3 countries : [ "Afghanistan", "Albania", "Algeria", "..." ],
4 states : [ "Alabama", "Alaska", "Alberta", "..." ],
5 states_us : [ "Alabama", "Alaska", "American Samoa", "..." ],
6 counties : [ "Abbeville", "Acadia", "Accomack", "..." ],
7 iso3s : [ "ABW", "AFG", "AGO", "..." ],
8 uids : [ 4, 8, 12, ... ],
9 first_date : 2020-01-22T00:00:00.000+00:00,
10 last_date : 2021-08-17T00:00:00.000+00:00

And it contains the list of countries that I want, which is the list of all the countries that exist in the Johns Hopkins University data set.

Now that we have everything we need to build our React website, let's code!

#Building the Website

If you followed all the instructions so far, here is what your working folder should look like:

2├── package.json
3├── package-lock.json
4├── public
5│   ├── favicon.ico
6│   └── index.html
8└── src

The current favicon is the React logo. You can totally replace it with the MongoDB one 😎.

Let's now edit the contents of public/index.html. Nothing really fancy compared to the original version that came with the sample application. I just removed what wasn't necessary.

1<!DOCTYPE html>
2<html lang="en">
4 <meta charset="utf-8"/>
5 <link rel="icon" href="%PUBLIC_URL%/favicon.ico"/>
6 <meta name="robots" content="noindex" />
7 <meta name="viewport" content="width=device-width, initial-scale=1"/>
8 <meta name="theme-color" content="#000000"/>
9 <meta name="description" content="Demo Application using MongoDB, React and Axios."/>
10 <title>MongoDB React REST API</title>
13<noscript>You need to enable JavaScript to run this app.</noscript>
14<div id="root"></div>

The only thing that we need to notice in this file is the fact that we now have an empty div with an id root which we will use to inject our React content.

Let's create a new file src/index.js:

1import React from 'react';
2import ReactDOM from 'react-dom';
3import RestExample from "./RestExample";
5ReactDOM.render(<React.StrictMode> <RestExample/> </React.StrictMode>, document.getElementById('root'));

We are now injecting our React content into our website and the content will be what the new RestExample component will render.

Let's create this new function component in the file src/RestExample.js:

1import {useEffect, useState} from "react";
2import axios from "axios";
4const RestExample = () => {
5 const url = '';
6 const [countries, setCountries] = useState([]);
8 useEffect(() => {
9 axios.get(url).then(res => {
10 setCountries(;
11 })
12 }, [])
14 return <div className="App"> <h1>List of Countries</h1> <div> <ul> { => <li key={c}>{c}</li>)} </ul> </div> </div>
17export default RestExample;

You can now start the project with the command:

1npm start

There are a few things that are worth explaining here if you are new to React:

  • On line 6, we are creating a state, countries, that is initialised to an empty array and a function setCountries() that can alter the value of that variable. More documentation here.
  • With the help of the useEffect() function (starting at line 8) and the Axios library, we can execute the function once, extract the countries from the response, and set the countries values from our list. More documentation here.
  • Finally, our function component will render the returned content. The function iterates over the list of countries and transforms each of the strings into an <li> tag to create an HTML unordered list.

#Final Result

The final website should look like this:

Final result of the website with the list of countries.

If you got confused at any point, and your app isn't working, just clone the final project:

1git clone
2cd mongodb-realm-react-rest-api
3npm start


In this blog post, you learned how to create a basic React website that uses Axios to retrieve data from a MongoDB Atlas Cluster using a REST API implemented with MongoDB Realm.

In the next blog post in this series, we'll extend this project so that we can integrate some charts from MongoDB Charts. We'll show COVID-19 data for a country and select which country we want to filter by. Stay tuned!

If you have questions, please head to our developer community website where the MongoDB engineers and the MongoDB community will help you build your next big idea with MongoDB.

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More from this series

React + REST + Charts
  • Build a Simple Website with React, Axios, and a REST API Built with MongoDB Realm
  • MongoDB Charts Embedding SDK with React
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