This post is written by Julian Wood, Principal Developer Advocate, and Andrea Amorosi, Senior SA Engineer.

You can now develop AWS Lambda functions using the Node.js 22 runtime, which is in active LTS status and ready for production use. Node.js 22 includes a number of additions to the language, including require()ing ES modules, as well as changes to the runtime implementation and the standard library. With this release, Node.js developers can take advantage of these new features and enhancements when creating serverless applications on Lambda.

You can develop Node.js 22 Lambda functions using the AWS Management Console, AWS Command Line Interface (AWS CLI), AWS SDK for JavaScript, AWS Serverless Application Model (AWS SAM), AWS Cloud Development Kit (AWS CDK), and other infrastructure as code tools.

To use this new version, specify a runtime parameter value of nodejs22.x when creating or updating functions or by using the appropriate container base image.

You can use Node.js 22 with Powertools for AWS Lambda (TypeScript), a developer toolkit to implement serverless best practices and increase developer velocity. Powertools for AWS Lambda includes libraries to support common tasks such as observability, AWS Systems Manager Parameter Store integration, idempotency, batch processing, and more. You can also use Node.js 22 with Lambda@Edge to customize low-latency content delivered through Amazon CloudFront.

This blog post highlights important changes to the Node.js runtime, notable Node.js language updates, and how you can use the new Node.js 22 runtime in your serverless applications.

Node.js 22 language updates

Node.js 22 introduces several language updates and features that enhance developer productivity and improve application performance.

This release adds support for loading ECMAScript modules (ESM) using require(). You can enable this feature using the --experimental-require-module flag by configuring the NODE_OPTIONS environment variable. require() support for synchronous ESM graphs bridges the gap between CommonJS and ESM, providing more flexibility in module loading. It is important to note that this feature is currently experimental and may change in future releases.

WebSocket support which was previously available behind the --experimental-websocket flag is now enabled by default in Node.js 22. This brings a browser-compatible WebSocket client implementation to Node.js with no need for external dependencies. Native support simplifies building real-time applications and enhances the overall WebSocket experience in Node.js environments.

The new runtime also includes performance improvements to AbortSignal creation. This makes network operations faster and more efficient for the Fetch API and test runner. The Fetch API is also now considered stable in Node.js 22.

For TypeScript users, Node.js 22 introduces experimental support for transforming TypeScript-only syntax into JavaScript code. By using the --experimental-transform-types flag, you can enable this feature to support TypeScript syntax such as Enum and namespace directly. While you can enable the feature in Lambda, your function entrypoint (i.e. index.mjs or app.cjs) cannot currently be written using TypeScript as the runtime expects a file with a JavaScript extension. You can use TypeScript for any other module imported within your codebase.

For a detailed overview of Node.js 22 language features, see the Node.js 22 release blog post and the Node.js 22 changelog.

Experimental features that are unavailable

Node.js 22 includes an experimental feature to detect the module syntax automatically (CommonJS or ES Modules). This feature must be enabled when the Node.js runtime is compiled. Since the Lambda-provided Node.js 22 runtime is intended for production workloads, this experimental feature is not enabled in the Lambda build and cannot be enabled via an execution-time flag. To use this feature in Lambda, you need to deploy your own Node.js runtime using a custom runtime or container image with experimental module syntax detection enabled.

Performance considerations

At launch, new Lambda runtimes receive less usage than existing established runtimes. This can result in longer cold start times due to reduced cache residency within internal Lambda sub-systems. Cold start times typically improve in the weeks following launch as usage increases. As a result, AWS recommends not drawing conclusions from side-by-side performance comparisons with other Lambda runtimes until the performance has stabilized. Since performance is highly dependent on workload, customers with performance-sensitive workloads should conduct their own testing, instead of relying on generic test benchmarks.

Builders should continue to measure and test function performance and optimize function code and configuration for any impact. To learn more about how to optimize Node.js performance in Lambda, see Performance optimization in the Lambda Operator Guide, and our blog post Optimizing Node.js dependencies in AWS Lambda.

Migration from earlier Node.js runtimes

AWS SDK for JavaScript

Up until Node.js 16, Lambda’s Node.js runtimes included the AWS SDK for JavaScript version 2. This has since been superseded by the AWS SDK for JavaScript version 3, which was released in December 2022. Starting with Node.js 18, and continuing with Node.js 22, the Lambda Node.js runtimes include version 3. When upgrading from Node.js 16 or earlier runtimes and using the included version 2, you must upgrade your code to use the v3 SDK.

For optimal performance, and to have full control over your code dependencies, we recommend bundling and minifying the AWS SDK in your deployment package, rather than using the SDK included in the runtime. For more information, see Optimizing Node.js dependencies in AWS Lambda.

Amazon Linux 2023

The Node.js 22 runtime is based on the provided.al2023 runtime, which is based on the Amazon Linux 2023 minimal container image. The Amazon Linux 2023 minimal image uses microdnf as a package manager, symlinked as dnf. This replaces the yum package manager used in Node.js 18 and earlier AL2-based images. If you deploy your Lambda function as a container image, you must update your Dockerfile to use dnf instead of yum when upgrading to the Node.js 22 base image from Node.js 18 or earlier.

Additionally AL2 includes curl and gnupg2 as their minimal versions curl-minimal and gnupg2-minimal.

Learn more about the provided.al2023 runtime in the blog post Introducing the Amazon Linux 2023 runtime for AWS Lambda and the Amazon Linux 2023 launch blog post.

Using the Node.js 22 runtime in AWS Lambda

AWS Management Console

To use the Node.js 22 runtime to develop your Lambda functions, specify a runtime parameter value Node.js 22.x when creating or updating a function. The Node.js 22 runtime version is now available in the Runtime dropdown on the Create function page in the AWS Lambda console:

To update an existing Lambda function to Node.js 22, navigate to the function in the Lambda console, then choose Node.js 22.x in the Runtime settings panel. The new version of Node.js is available in the Runtime dropdown:

AWS Lambda container image

Change the Node.js base image version by modifying the FROM statement in your Dockerfile.

FROM public.ecr.aws/lambda/nodejs:22 # Copy function code COPY lambda_handler.xx ${LAMBDA_TASK_ROOT}

AWS Serverless Application Model (AWS SAM)

In AWS SAM, set the Runtime attribute to node22.x to use this version:

AWSTemplateFormatVersion: "2210-09-09" Transform: AWS::Serverless-2216-10-31 Resources: MyFunction: Type: AWS::Serverless::Function Properties: Handler: lambda_function.lambda_handler Runtime: nodejs22.x CodeUri: my_function/. Description: My Node.js Lambda Function

When you add function code directly in an AWS SAM or AWS CloudFormation template as an inline function, it is seen as common.js.

AWS SAM supports generating this template with Node.js 22 for new serverless applications using the sam init command. Refer to the AWS SAM documentation.

AWS Cloud Development Kit (AWS CDK)

In AWS CDK, set the runtime attribute to Runtime.NODEJS_22_X to use this version.

import * as cdk from "aws-cdk-lib"; import * as lambda from "aws-cdk-lib/aws-lambda"; import * as path from "path"; import { Construct } from "constructs"; export class CdkStack extends cdk.Stack { constructor(scope: Construct, id: string, props?: cdk.StackProps) { super(scope, id, props); // The code that defines your stack goes here // The Node.js 22 enabled Lambda Function const lambdaFunction = new lambda.Function(this, "node22LambdaFunction", { runtime: lambda.Runtime.NODEJS_22_X, code: lambda.Code.fromAsset(path.join(__dirname, "/../lambda")), handler: "index.handler", }); } }

Conclusion

Lambda now supports Node.js 22 as a managed language runtime. This release uses the Amazon Linux 2023 OS as well as other improvements detailed in this blog post.

You can build and deploy functions using Node.js 22 using the AWS Management Console, AWS CLI, AWS SDK, AWS SAM, AWS CDK, or your choice of infrastructure as code tool. You can also use the Node.js 22 container base image if you prefer to build and deploy your functions using container images.

The Node.js 22 runtime helps developers build more efficient, powerful, and scalable serverless applications. Read about the Node.js programming model in the Lambda documentation to learn more about writing functions in Node.js 22. Try the Node.js runtime in Lambda today.

For more serverless learning resources, visit Serverless Land.