React and AWS Lambda: Building Serverless APIs

The development of web applications has evolved significantly over the past few years. With the introduction of serverless architecture, developers have found a new way to build and deploy their applications. Serverless architecture eliminates the need for managing infrastructure and allows developers to focus on writing code that solves business problems. AWS Lambda is one of the most popular serverless platforms that enables developers to build serverless APIs. In this article, we will discuss how to build serverless APIs with React and AWS Lambda.

React is a popular JavaScript library for building user interfaces. It provides a powerful set of features that allows developers to build complex UIs with ease. AWS Lambda, on the other hand, is a serverless computing platform that allows developers to run their code without managing servers. It can be used to build serverless APIs that can be used by web applications.

Building a Serverless API with AWS Lambda

To build a serverless API with AWS Lambda, we need to follow these steps:

Step 1: Create a new Lambda function

The first step is to create a new Lambda function in the AWS Console. We can choose the programming language that we want to use to write our Lambda function. AWS Lambda supports several programming languages, including Node.js, Python, Java, and C#. For this example, we will use Node.js.

Step 2: Write the Lambda function

Once we have created the Lambda function, we can start writing the code for our API. We can use the AWS SDK to interact with other AWS services like DynamoDB or S3. We can also use third-party libraries to perform certain tasks.

For example, if we want to retrieve data from a DynamoDB table, we can use the AWS SDK for Node.js to query the table and return the data as a JSON response. Here is an example of a Lambda function that retrieves data from a DynamoDB table:

const AWS = require('aws-sdk');
const docClient = new AWS.DynamoDB.DocumentClient();

exports.handler = async (event) => {
    const params = {
        TableName: 'my-table-name',
        Key: {
    try {
        const data = await docClient.get(params).promise();
        const response = {
            statusCode: 200,
            body: JSON.stringify(data.Item)
        return response;
    } catch (err) {
        const response = {
            statusCode: 500,
            body: JSON.stringify(err)
        return response;

In this example, we are using the DocumentClient class from the AWS SDK to query a DynamoDB table. The Lambda function takes an id parameter from the request path and uses it to query the table. If the item is found, it returns the item as a JSON response with a 200 status code. If there is an error, it returns a 500 status code with the error message.

Step 3: Deploy the Lambda function

Once we have written the Lambda function, we need to deploy it to AWS Lambda. We can do this using the AWS CLI or the AWS Console. After deploying the function, we can test it using the Test feature in the AWS Console.

Building a React application that uses the serverless API

Now that we have built the serverless API, we can build a React application that uses it. We can use the fetch API to make HTTP requests to our serverless API. Here is an example of a React component that retrieves data from our serverless API:

import React, { useState, useEffect } from 'react';

function App() {
  const [data, setData] = useState(null);
  useEffect(() => {
    async function fetchData() {
      const response = await fetch('https://my-api-gateway-url/path/to/my/lambda-function?id=1');
      const json = await response.json();
  }, []);

  if (!data) {
    return <div>Loading...</div>;

  return (

export default App;

In this example, we use the useState hook to manage the state of our component. We also use the useEffect hook to fetch data from our serverless API when the component is mounted. We use the fetch API to make a GET request to our serverless API endpoint and parse the JSON response.


In this article, we have discussed how to build serverless APIs with React and AWS Lambda. We have also seen how to build a React application that uses our serverless API. Serverless architecture provides developers with a new way to build and deploy their applications. With AWS Lambda, we can build serverless APIs that can be used by our web applications. Combining React and AWS Lambda allows us to build scalable and efficient web applications.