Published Dec 22, 2023 ⦁ 16 min read
AWS SDK JavaScript Essentials

AWS SDK JavaScript Essentials

Most developers would agree that integrating AWS services into JavaScript apps can be challenging.

But with the AWS SDK for JavaScript, you can easily build full-stack apps that leverage AWS's robust infrastructure and services.

In this post, you'll learn the basics of the AWS JavaScript SDK - from setup and configuration, to core use cases like Amazon S3, DynamoDB, and EC2. You'll see hands-on examples for integrating AWS services into Node.js and browser apps with just a few lines of code.

Introduction to AWS SDK for JavaScript

The AWS SDK for JavaScript allows developers to build applications that leverage AWS services like S3, DynamoDB, and more from JavaScript environments. Here are some of the key things to know about the AWS SDK for JavaScript:

Exploring the AWS SDK JavaScript API Reference

The AWS SDK for JavaScript provides a comprehensive API reference detailing all the available classes, methods, and events across services. This is useful for finding specifics on how to configure service clients, make API requests, handle responses, set security credentials, and more.

Key things the API reference covers:

  • Class documentation for service clients, commands, responses, and configuration
  • Code examples for initialization, requests, responses
  • Events, parameters, properties across AWS services
  • Links to source code on GitHub

Understanding the Modular Architecture of AWS SDK JavaScript

The AWS SDK JavaScript v3 introduced a modular architecture that allows developers to only import the specific AWS services needed. This is beneficial for:

  • Reducing bundle size instead of the entire SDK
  • Tree shaking to eliminate unused modules
  • Customizing builds to use desired services

For example, an application using Amazon S3 and DynamoDB can do:

import { S3 } from "@aws-sdk/client-s3"; 
import { DynamoDB } from "@aws-sdk/client-dynamodb";

The Evolution from AWS SDK JavaScript (v2) to v3

The AWS SDK JavaScript upgraded from v2 to v3 in 2020, with some key improvements:

  • Modular architecture as mentioned above
  • Updated to use modern JavaScript standards
  • Better support for TypeScript
  • New middleware pipeline

So v3 introduces a lot more customization, flexibility, and modern JS idioms while still providing wide service coverage.

Why Developers Choose AWS SDK for JavaScript

There are a few key reasons developers choose AWS SDK for JavaScript:

  • Supports all major JS environments: Node.js, browsers, React Native
  • Access to over 250+ AWS service APIs
  • Handles authentication, requests, responses
  • Integrates with AWS services for building applications
  • Large community and ecosystem around AWS

Overall, it provides a complete toolset for integrating AWS cloud functionality in JavaScript apps.

How to use AWS SDK in JavaScript?

Here are the key steps to get started with using the AWS SDK for JavaScript:

Step 1: Install the SDK and Dependencies

You install the SDK for JavaScript package using npm (the Node.js package manager).

npm install aws-sdk

You'll also need to install Node.js if you don't already have it.

Step 2: Configure Your Credentials

Before making requests, you need to configure your AWS credentials and region. You can do this by creating an AWS credentials file or passing credentials directly in code.

Step 3: Import the AWS SDK

Import the AWS SDK services you'll be using in your JavaScript file. For example:

import { S3 } from 'aws-sdk';

Step 4: Create a Service Object

Instantiate the service object with the configured credentials and region information.

const s3 = new S3({

Step 5: Make API Calls

You can now call AWS service APIs and handle responses. For example, to list S3 buckets:

s3.listBuckets((err, data) => {
  if (err) {
  } else {

That covers the basics of using the AWS SDK for JavaScript! Check the documentation for more details on configuration, services, and use cases.

Does AWS work with JavaScript?

AWS SDK for JavaScript provides a set of libraries to integrate AWS services into JavaScript applications. It supports three types of JavaScript applications:

Browser Applications

The SDK can be used in front-end browser applications built with frameworks like React, Angular, and Vue. It provides browser-compatible versions of the AWS services.

Node.js Applications

The SDK integrates seamlessly with Node.js backends. It enables building serverless applications using AWS Lambda and other services.

React Native Mobile Apps

The SDK works with React Native to build mobile applications for iOS and Android. It provides access to AWS services from within React Native.

The SDK is open-source and available via npm. It has a modular architecture allowing developers to only import the specific AWS services they need. The getting started guide on GitHub covers the basics of installation and configuration.

Overall, the AWS SDK for JavaScript enables integrating AWS cloud services into JavaScript applications. Its browser compatibility and support for Node.js and React Native makes AWS accessible across different JavaScript environments.

Why we use AWS SDK in node JS?

The AWS SDK for JavaScript provides a convenient way to interact with AWS services from Node.js applications. Here are some of the key reasons why using the AWS SDK is beneficial:

  • Easy setup: The SDK can be installed from npm with a single command npm install aws-sdk. This allows you to get up and running quickly.
  • Idiomatic APIs: The SDK provides idiomatic JavaScript APIs for AWS services that feel natural to use in Node.js code. This includes promises and async/await support.
  • Modular architecture: The SDK has a modular architecture so you only need to install the specific AWS services your app uses. This keeps bundle sizes small.
  • TypeScript support: The SDK provides TypeScript type definitions out of the box, enabling you to benefit from static typing in TypeScript projects.
  • Configurable: The SDK makes it easy to configure things like AWS regions, credentials, and API settings. This allows customizing it to your needs.
  • Lightweight: The runtime footprint of the SDK is small. This is important for serverless deployments where bundle size matters.

In summary, using the official AWS SDK for JavaScript simplifies interacting AWS services by handling authentication, retries, marshaling HTTP requests, and more. Its idiomatic design and lightweight nature makes it a great fit for Node.js applications.

What is SDK in JavaScript?

An SDK (software development kit) in JavaScript typically refers to a library that allows developers to interact with a specific API or service.

Some key things to know about JavaScript SDKs:

  • They abstract away the underlying API calls and authentication, making it easier for developers to integrate with services.
  • They provide helper functions and tools tailored to that specific service.
  • Popular services like AWS, Twilio, and Stripe offer official JavaScript SDKs.
  • JavaScript SDKs can be used in web apps, Node.js backends, and JavaScript-based mobile apps.
  • They often support modern JS features like async/await and TypeScript.

For example, the AWS JavaScript SDK allows developers to call AWS services like S3, DynamoDB, and Lambda from their JavaScript code. It handles authentication, request signing, and response parsing.

So in summary, JS SDKs reduce boilerplate code and provide an easier way to leverage external APIs and cloud services from JavaScript environments. They save developers time and effort.


Setting Up the AWS SDK for JavaScript

Installing the AWS SDK JavaScript npm Package

To install the AWS SDK for JavaScript, run the following command in your Node.js project:

npm install aws-sdk

This will install the latest version of the AWS SDK for JavaScript from npm.

Once installed, you can require and initialize the SDK in your code like so:

const AWS = require('aws-sdk');
const s3 = new AWS.S3(); 

Configuring the AWS SDK JavaScript in Node.js

There are a few ways to configure the AWS SDK for JavaScript in Node.js:

  • Set credentials by instantiating AWS with an access key and secret access key:
const AWS = require('aws-sdk');

  accessKeyId: 'YOUR_ACCESS_KEY', 
  secretAccessKey: 'YOUR_SECRET_KEY'
  • Set credentials via environment variables:
  • Use an IAM role if running on EC2 or Lambda

Integrating AWS SDK JavaScript in Browser Applications

To use the AWS SDK in the browser, include the SDK script in your HTML:

<script src=""></script>  

Then initialize like so:

var s3 = new AWS.S3({
  apiVersion: '2006-03-01',
  params: {Bucket: 'myBucket'}

The SDK will use browser cookies for credentials, so be sure to set the right IAM permissions.

AWS SDK JavaScript Setup in React Native

Import and initialize the AWS SDK in React Native similarly to Node.js:

import AWS from 'aws-sdk/dist/aws-sdk-react-native';

const dynamoDB = new AWS.DynamoDB({
  apiVersion: '2012-08-10'

Be sure to configure credentials properly using one of the methods mentioned above.

Core AWS SDK JavaScript Use Cases

Working with Amazon S3 using AWS SDK JavaScript

The AWS SDK for JavaScript makes it easy to integrate Amazon S3 into your applications. Here is a step-by-step guide to some of the most common S3 operations:

Uploading Files to S3

To upload a file to an S3 bucket, first configure the S3 client and specify the bucket name and file key:

const { S3Client, PutObjectCommand } = require("@aws-sdk/client-s3");

const client = new S3Client({ region: "us-east-1" });

const params = {
  Bucket: "my-bucket", 
  Key: "path/to/file.txt",
  Body: "Hello world!"

Then call putObject() and pass the parameters:

const response = await client.send(new PutObjectCommand(params));

The response contains metadata like the file's ETag and version ID.

Listing Buckets

To list all S3 buckets for your account, call listBuckets():

const response = await client.send(new ListBucketsCommand({}));

The Buckets property contains an array of bucket metadata.

Managing Access with Bucket Policies

You can control access to buckets using bucket policies. Here is an example policy allowing public read access:

const publicPolicyParams = {
  Bucket: "my-bucket", 
  Policy: JSON.stringify({
      Principal: "*",

await client.send(new PutBucketPolicyCommand(publicPolicyParams));

Interacting with DynamoDB through AWS SDK JavaScript

The AWS SDK for JavaScript provides full access to DynamoDB for creating tables, inserting data, running queries, and more.

Creating a Table

Use the CreateTableCommand to create a DynamoDB table:

const params = {
  TableName : "Users",
  KeySchema: [       
    { AttributeName: "username", KeyType: "HASH"}
  AttributeDefinitions: [       
    { AttributeName: "username", AttributeType: "S" }
  ProvisionedThroughput: {       
    ReadCapacityUnits: 5,       
    WriteCapacityUnits: 5

const command = new CreateTableCommand(params);
await client.send(command);

This creates a table with a simple primary key on the username attribute.

Inserting Data

To insert items into DynamoDB, use the PutItemCommand:

const params = {
  TableName : "Users",
  Item: {
    username : { S: "john123" },
    firstName: { S: "John" },
    lastName: { S: "Doe" }

await client.send(new PutItemCommand(params)); 

The item data is specified as a set of attribute name/value pairs.

Querying Data

Use QueryCommand to retrieve items based on the primary key:

const params = {
  TableName : "Users",
  KeyConditionExpression: "username = :v_user",
  ExpressionAttributeValues: {
    ":v_user": { S: "john123" }

const data = await client.send(new QueryCommand(params));

This queries for the item with username = "john123". The Items property contains matching results.

Managing AWS IAM Roles and Policies with AWS SDK JavaScript

The AWS SDK for JavaScript allows you to programmatically manage IAM permissions.

Creating a New User

To create an IAM user, call CreateUserCommand:

const params = { UserName: "my-user" };
await iamClient.send(new CreateUserCommand(params));

This will create a new user called my-user.

Attaching Managed Policies

You can attach managed policies to IAM users with AttachUserPolicyCommand:

const params = {
  UserName: "my-user",
  PolicyArn: "arn:aws:iam::aws:policy/ReadOnlyAccess"  

await iamClient.send(new AttachUserPolicyCommand(params)); 

This grants the ReadOnlyAccess policy to my-user.

Creating Custom Inline Policies

To assign a custom inline policy to a user:

const params = {
  UserName: "my-user",
  PolicyName: "CustomPolicy",
  PolicyDocument: {
    "Version": "2012-10-17",
    "Statement": [
        "Effect": "Allow",        
        "Action": ["s3:Get*", "s3:List*"],        
        "Resource": "*"

await iamClient.send(new PutUserPolicyCommand(params));

This allows my-user to perform read-only S3 actions.

Launching and Managing EC2 Instances with AWS SDK JavaScript

You can use the AWS SDK for JavaScript to launch, configure and manage EC2 instances.

Launching an Instance

Use RunInstancesCommand to launch an EC2 instance:

const params = {
  ImageId: "ami-0c55b159cbfafe1f0", 
  InstanceType: "t2.micro",
  KeyName: "my-key-pair",  
  MinCount: 1,
  MaxCount: 1

const data = await ec2Client.send(new RunInstancesCommand(params));

This launches a t2.micro instance using the specified AMI and key pair.

Creating Tags

To tag the instance, call CreateTagsCommand:

params = {
  Resources: [data.Instances[0].InstanceId],
  Tags: [
    { Key: "Name", Value: "My web server" }

await ec2Client.send(new CreateTagsCommand(params));

This creates a "Name" tag for the instance.

Checking Instance Status

To check the status of an instance, use DescribeInstancesCommand:

params = { InstanceIds: [data.Instances[0].InstanceId] };

const statusData = await ec2Client.send(new DescribeInstancesCommand(params)); 

This prints the current state of the instance, e.g. "running".

Advanced Features and Best Practices

Leveraging AWS SDK JavaScript Middleware Stack

The AWS SDK for JavaScript provides a middleware stack that allows for custom processing of requests and responses. This can be useful for:

  • Logging - Adding logging for debugging purposes or analytics
  • Retries - Implementing custom retry logic for failed requests
  • Metrics - Tracking metrics like number of requests
  • Validation - Validating parameters before sending requests

To use middleware, you specify the middleware function when creating the AWS service client. For example:

import { S3 } from "@aws-sdk/client-s3";

const s3 = new S3({
  middleware: [myMiddleware],

The middleware function receives context about the request and handlers to call the next middleware in the stack.

TypeScript Support in AWS SDK JavaScript

The AWS SDK for JavaScript has first-class support for TypeScript. This brings advantages like:

  • Type safety - TypeScript can catch bugs during development
  • Code completion - Improved editor tooling and suggestions
  • Documentation - Types act as documentation for the API

To use with TypeScript, install the TypeScript type definitions:

npm install @aws-sdk/types

You can then import the types for services you use:

import { S3 } from "@aws-sdk/client-s3"; 

Optimizing AWS SDK JavaScript for Lambda Functions

To optimize performance of AWS SDK for JavaScript within Lambda functions:

  • Use smaller SDK modules instead of the entire SDK to minimize code size
  • Keep clients outside of the function handler to enable reuse
  • Use environment credentials provider over hardcoded credentials
  • Set HTTP keep-alive option to maximize connection reuse

This minimizes cold starts and improves performance.

Troubleshooting and Debugging AWS SDK JavaScript Applications

Common issues when using AWS SDK for JavaScript include:

  • Credential errors - Ensure credentials are set correctly
  • Access errors - Check IAM policies attached to credentials
  • Invalid parameters - Double check inputs match required formats
  • Throttling - Implement exponential backoff for retries

Enable debug logging and inspect network requests to troubleshoot. Check CloudWatch logs for details on errors.

AWS SDK JavaScript Resources and Tutorials

AWS SDK for JavaScript provides developers with tools and libraries for building applications that interact with AWS services. To fully leverage the power of the SDK, it helps to explore the many learning resources available.

Exploring the AWS SDK JavaScript Developer Guide

The AWS SDK for JavaScript Developer Guide is the official manual for working with the SDK. It includes:

  • Step-by-step tutorials for getting started
  • Best practices for configuration, security, performance
  • API reference documentation
  • Sample code and examples for common use cases

Developers should thoroughly read through the Developer Guide to understand how to properly structure applications using AWS services and the SDK.

Learning Through AWS SDK JavaScript Examples

The AWS SDK Code Examples Repository contains sample JavaScript code demonstrating use of services like S3, DynamoDB, EC2 and more. These real-world examples can supplement developer guide learnings:

  • See SDK APIs used in complete application context
  • Find samples closely matching a desired use case
  • Learn how services integrate with SDK features

Copying, running and modifying these samples accelerates the learning process.

AWS SDK JavaScript GitHub Repository Insights

The AWS SDK JavaScript repo is also a great resource. Developers can:

  • View and contribute to SDK source code
  • Track issues and feature requests
  • Test preview releases before general availability
  • Report bugs and submit fixes

Engaging in the repo brings insight into SDK design and future direction.

Following an AWS SDK JavaScript Tutorial for Hands-on Practice

Third-party tutorials offer step-by-step application development guides:

  • Building Serverless Web Applications - end-to-end tutorial from AWS
  • Creating an AWS App with the JS SDK - uses React and Amplify
  • Building Chat App on AWS - real-time chat with WebSocket API

These tutorials allow hands-on practice while building complete apps. They are a great way to apply learnings.

Combining these resources provides paths for mastering AWS SDK for JavaScript to unlock the potential of cloud applications.

Conclusion: Harnessing the Power of AWS SDK for JavaScript

Recap of AWS SDK JavaScript Essentials

The AWS SDK for JavaScript provides essential tools for building cloud-based applications. This article covered key concepts like:

  • Setup and configuration - Installing the SDK modules with NPM and configuring credentials for accessing AWS services
  • Modular architecture - Importing just the specific service clients you need
  • Promises and async/await - Using modern asynchronous JavaScript patterns
  • Basic requests - Querying resources, uploading files to S3 buckets, writing items to DynamoDB tables

With these fundamentals, you can start integrating AWS services into your Node.js and browser apps using idiomatic JavaScript.

Next Steps in Mastering AWS SDK for JavaScript

To continue mastering the AWS SDK for JavaScript:

  • Refer to the API reference documentation for detailed service APIs
  • Try out more advanced use cases like Lambda functions, authentication, and notifications
  • Join AWS developer community forums to discuss best practices
  • Learn how TypeScript support enhances development workflows
  • Explore custom middleware to handle logging, retries, monitoring, and more

Building on this initial foundation, you will be equipped to leverage the full breadth and depth of capabilities across AWS services.