@monolayer/nextjs-lambda-adapter v4.0.5

Next.js Lambda Adapter

AWS Lambda adapter for Next.js applications (App Router).

This adapter replicates the behaviour (has feature parity) of a self-hosted Next.js (App Router) application in a serverless environment (AWS Lambda).

Caching and revalidation of pages (with Incremental Static Regeneration) is managed with a custom cache handler that ensures consistency across all function invocations. (based on S3 and DynamoDB).

For production environments, you should configure a CloudFront distribution to serve static and public assets from an S3 Bucket. By default, ALL application traffic will be handled by the Lambda function.

Prerequisites

• Next.js application built with standalone mode. (v15 tested, v14 untested)
• AWS Account

Usage

After building your application, run:

npx --yes @monolayer/nextjs-lambda-adapter

This will install the Lambda adapter in the standalone folder of your build.

Deployment

You can now package your application as a Lambda function.

Packaging Notes

• You should copy the .next/static folder to the .next/standalone/.next directory.
• You should copy the public folder to the .next/standalone directory.

Here's an example packaging script:

cp -r public .next/standalone/
cp -r .next/static .next/standalone/.next/
npx --yes @monolayer/nextjs-lambda-adapter@latest

The Lambda function must be configured as follows:

• Handler: adapter/index.handler.
• Environment Variables:
  • NEXTJS_ADAPTER_CACHE_BUCKET_NAME (required): name of the bucket for the cache items.
  • NEXTJS_ADAPTER_DYNAMODB_TAGS_TABLE (required): name of the DynamoDB table for the cache tags.
  • NEXTJS_ADAPTER_CLOUDFRONT_DOMAIN (optional): CloudFront distribution domain name. To allow server actions to be called from a CloudFront distribution.
  • NEXTJS_ADAPTER_CACHE_DEBUG (optional): Set to true to print cache operations.
• Permissions: read/write permissions to the S3 Bucket and DynamoDB table.

The ImageOptimizationCache will write to the ephemeral storage at /tmp/cache. By default lambda functions have 512MB of ephimeral storage.

Example

Here's a sample AWS SAM template template.yaml to deploy a barebones application:

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31

Parameters:
  CacheBucketName:
    Type: String
  DynamoDBTableName:
    Type: String

Resources:
  CacheBucket:
    Type: AWS::S3::Bucket
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
    Properties:
      BucketName: !Ref CacheBucketName
      PublicAccessBlockConfiguration:
        BlockPublicAcls: true
        BlockPublicPolicy: true
        IgnorePublicAcls: true
        RestrictPublicBuckets: true
  DynamoDbTagsTable:
    Type: AWS::DynamoDB::Table
    DeletionPolicy: Delete
    UpdateReplacePolicy: Delete
    Properties:
      TableName: !Ref DynamoDBTableName
      AttributeDefinitions:
        - AttributeName: PK
          AttributeType: S
      KeySchema:
        - AttributeName: PK
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
      TableClass: STANDARD
  AppFn:
    Type: AWS::Serverless::Function
    DependsOn: DynamoDbTagsTable
    Properties:
      CodeUri: ./.next/standalone
      Handler: adapter/index.handler
      PackageType: Zip
      MemorySize: 1536
      Runtime: nodejs22.x
      Timeout: 20
      Architectures:
        - arm64
      FunctionUrlConfig:
        AuthType: NONE
        InvokeMode: RESPONSE_STREAM
      Environment:
        Variables:
          NODE_ENV: production
          NEXTJS_ADAPTER_CACHE_BUCKET_NAME: !Ref CacheBucket
          NEXTJS_ADAPTER_DYNAMODB_TAGS_TABLE: !Ref DynamoDBTableName
      Policies:
        - S3CrudPolicy:
            BucketName: !Ref CacheBucket
        - DynamoDBCrudPolicy:
            TableName: !Ref DynamoDBTableName
    Metadata:
      SkipBuild: True