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Powertools is a developer toolkit to implement Serverless best practices and increase developer velocity.

You can use Powertools in both TypeScript and JavaScript code bases.

Tip

Powertools is also available for Python, Java, and .NET

Support this project by becoming a reference customer, sharing your work, or using Layers

You can choose to support us in three ways:

1) Become a reference customers. This gives us permission to list your company in our documentation.

2) Share your work. Blog posts, video, sample projects you used Powertools!

3) Use Lambda Layers, if possible. This helps us understand who uses Powertools in a non-intrusive way, and helps us gain future investments for other Lambda Powertools languages.

When using Layers, you can add Lambda Powertools as a devDependency to not impact the development process.

Install

Powertools is available in the following formats:

• Lambda Layer: arn:aws:lambda:{region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
• npm: npm install @aws-lambda-powertools/tracer @aws-lambda-powertools/metrics @aws-lambda-powertools/logger

Lambda Layer

Lambda Layer is a .zip file archive that can contain additional code, pre-packaged dependencies, data, or configuration files. Layers promote code sharing and separation of responsibilities so that you can iterate faster on writing business logic.

You can include Lambda Powertools Lambda Layer using AWS Lambda Console, or your preferred deployment framework.

Note: Click to expand and copy any regional Lambda Layer ARN

Region	Layer ARN
us-east-1	arn:aws:lambda:us-east-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
us-east-2	arn:aws:lambda:us-east-2:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
us-west-1	arn:aws:lambda:us-west-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
us-west-2	arn:aws:lambda:us-west-2:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-south-1	arn:aws:lambda:ap-south-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-northeast-1	arn:aws:lambda:ap-northeast-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-northeast-2	arn:aws:lambda:ap-northeast-2:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-northeast-3	arn:aws:lambda:ap-northeast-3:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-southeast-1	arn:aws:lambda:ap-southeast-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ap-southeast-2	arn:aws:lambda:ap-southeast-2:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
eu-central-1	arn:aws:lambda:eu-central-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
eu-west-1	arn:aws:lambda:eu-west-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
eu-west-2	arn:aws:lambda:eu-west-2:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
eu-west-3	arn:aws:lambda:eu-west-3:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
eu-north-1	arn:aws:lambda:eu-north-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
ca-central-1	arn:aws:lambda:ca-central-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
sa-east-1	arn:aws:lambda:sa-east-1:094274105915:layer:AWSLambdaPowertoolsTypeScript:7

Note: Click to expand and copy code snippets for popular frameworks

SAMServerless frameworkCDKTerraformPulumiAmplifyGet the Layer .zip contents

MyLambdaFunction:
  Type: AWS::Serverless::Function
    Properties:
      Layers:
        - !Sub arn:aws:lambda:${AWS::Region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7

If you use esbuild to bundle your code, make sure to exclude @aws-lambda-powertools from being bundled since the packages will be already present the Layer:

MyLambdaFunction:
  Type: AWS::Serverless::Function
  Properties:
    ...
    Metadata: 
      # Manage esbuild properties
      BuildMethod: esbuild
      BuildProperties:
      Minify: true
      External:
        - '@aws-lambda-powertools/commons'
        - '@aws-lambda-powertools/logger'
        - '@aws-lambda-powertools/metrics'
        - '@aws-lambda-powertools/tracer'

Check the documentation for more details.

functions:
  hello:
    handler: lambda_function.lambda_handler
    layers:
      - arn:aws:lambda:${aws::region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7

If you use esbuild to bundle your code, make sure to exclude @aws-lambda-powertools from being bundled since the packages will be already present the Layer:

custom:
  esbuild:
    external:
      - '@aws-lambda-powertools/commons'
      - '@aws-lambda-powertools/logger'
      - '@aws-lambda-powertools/metrics'
      - '@aws-lambda-powertools/tracer'

Check the documentation for more details.

import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as lambda from 'aws-cdk-lib/aws-lambda';

export class SampleFunctionWithLayer extends Construct {
  constructor(scope: Construct, id: string) {
    super(scope, id);

    // Create a Layer with AWS Lambda Powertools for TypeScript
    const powertoolsLayer = lambda.LayerVersion.fromLayerVersionArn(
      this,
      'PowertoolsLayer',
      `arn:aws:lambda:${cdk.Stack.of(this).region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7`
    );

    new lambda.Function(this, 'Function', {
      runtime: lambda.Runtime.NODEJS_16_X,
      // Add the Layer to a Lambda function
      layers: [powertoolsLayer],
      code: lambda.Code.fromInline(`...`),
      handler: 'index.handler',
    });
  }
}

If you use esbuild to bundle your code, make sure to exclude @aws-lambda-powertools from being bundled since the packages will be already present the Layer:

new awsLambdaNodejs.NodejsFunction(this, 'Function', {
  ...
  bundling: {
    externalModules: [
      '@aws-lambda-powertools/commons',
      '@aws-lambda-powertools/logger',
      '@aws-lambda-powertools/metrics',
      '@aws-lambda-powertools/tracer',
    ],
  }
});

Check the documentation for more details.

terraform {
  required_version = "~> 1.0.5"
  required_providers {
    aws = "~> 3.50.0"
  }
}

provider "aws" {
  region  = "{aws::region}"
}

resource "aws_lambda_function" "test_lambda" {
  filename      = "lambda_function_payload.zip"
  function_name = "lambda_function_name"
  role          = ...
  handler       = "index.handler"
  runtime       = "nodejs16.x"
  layers        = ["arn:aws:lambda:{aws::region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7"]
  source_code_hash = filebase64sha256("lambda_function_payload.zip")
}

import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

const role = new aws.iam.Role("role", {
    assumeRolePolicy: aws.iam.assumeRolePolicyForPrincipal(aws.iam.Principals.LambdaPrincipal),
    managedPolicyArns: [aws.iam.ManagedPolicies.AWSLambdaBasicExecutionRole]
});

const lambdaFunction = new aws.lambda.Function("function", {
    layers: [
        pulumi.interpolate`arn:aws:lambda:${aws.getRegionOutput().name}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7`
    ],
    code: new pulumi.asset.FileArchive("lambda_function_payload.zip"),
    tracingConfig: {
        mode: "Active"
    },
    runtime: aws.lambda.Runtime.NodeJS16dX,
    handler: "index.handler",
    role: role.arn,
    architectures: ["x86_64"]
});

# Create a new one with the layer
❯ amplify add function
? Select which capability you want to add: Lambda function (serverless function)
? Provide an AWS Lambda function name: <NAME-OF-FUNCTION>
? Choose the runtime that you want to use: NodeJS
? Do you want to configure advanced settings? Yes
...
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:{aws::region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
❯ amplify push -y

# Updating an existing function and add the layer
❯ amplify update function
? Select the Lambda function you want to update test2
General information
- Name: <NAME-OF-FUNCTION>
? Which setting do you want to update? Lambda layers configuration
? Do you want to enable Lambda layers for this function? Yes
? Enter up to 5 existing Lambda layer ARNs (comma-separated): arn:aws:lambda:{aws::region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7
? Do you want to edit the local lambda function now? No

aws lambda get-layer-version-by-arn --arn arn:aws:lambda:{aws::region}:094274105915:layer:AWSLambdaPowertoolsTypeScript:7 --region {region}

The pre-signed URL to download this Lambda Layer will be within Location key.

Warning: Limitations

Container Image deployment (OCI) or inline Lambda functions do not support Lambda Layers.

Instrumentation

You can instrument your code with Powertools in three different ways:

• Middy middleware. It is the best choice if your existing code base relies on the Middy middleware engine. Powertools offers compatible Middy middleware to make this integration seamless.
• Method decorator. Use TypeScript method decorators if you prefer writing your business logic using TypeScript Classes. If you aren’t using Classes, this requires the most significant refactoring.
• Manually. It provides the most granular control. It’s the most verbose approach, with the added benefit of no additional dependency and no refactoring to TypeScript Classes.

The examples in this documentation will feature all the approaches described above, when applicable.

Examples

The project's repository includes examples of how to instrument your functions both in AWS CDK and AWS SAM:

• AWS CDK
• AWS SAM

If instead you want to see Powertools for TypeScript in a slightly more complex use case, check the Serverless TypeScript Demo. You can find instructions on how to deploy and load test this application in the repository.

Features

Core utilities such as Tracing, Logging, and Metrics will be available across all Lambda Powertools languages. Additional utilities are subjective to each language ecosystem and customer demand.

Utility	Description
Tracer	Decorators and utilities to trace Lambda function handlers, and both synchronous and asynchronous functions
Logger	Structured logging made easier, and a middleware to enrich structured logging with key Lambda context details
Metrics	Custom Metrics created asynchronously via CloudWatch Embedded Metric Format (EMF)

Environment variables

Info

Explicit parameters take precedence over environment variables

Environment variable	Description	Utility	Default
POWERTOOLS_SERVICE_NAME	Sets service name used for tracing namespace, metrics dimension and structured logging	All	service_undefined
POWERTOOLS_METRICS_NAMESPACE	Sets namespace used for metrics	Metrics	default_namespace
POWERTOOLS_TRACE_ENABLED	Explicitly disables tracing	Tracer	true
POWERTOOLS_TRACER_CAPTURE_RESPONSE	Captures Lambda or method return as metadata.	Tracer	true
POWERTOOLS_TRACER_CAPTURE_ERROR	Captures Lambda or method exception as metadata.	Tracer	true
POWERTOOLS_TRACER_CAPTURE_HTTPS_REQUESTS	Captures HTTP(s) requests as segments.	Tracer	true
POWERTOOLS_LOGGER_LOG_EVENT	Logs incoming event	Logger	false
POWERTOOLS_LOGGER_SAMPLE_RATE	Debug log sampling	Logger	0
POWERTOOLS_DEV	Increase JSON indentation to ease debugging when running functions locally or in a non-production environment	Logger	false
LOG_LEVEL	Sets logging level	Logger	INFO

Each Utility page provides information on example values and allowed values

Tenets

These are our core principles to guide our decision making.

• AWS Lambda only. We optimise for AWS Lambda function environments and supported runtimes only. Utilities might work with web frameworks and non-Lambda environments, though they are not officially supported.
• Eases the adoption of best practices. The main priority of the utilities is to facilitate best practices adoption, as defined in the AWS Well-Architected Serverless Lens; all other functionality is optional.
• Keep it lean. Additional dependencies are carefully considered for security and ease of maintenance, and prevent negatively impacting startup time.
• We strive for backwards compatibility. New features and changes should keep backwards compatibility. If a breaking change cannot be avoided, the deprecation and migration process should be clearly defined.
• We work backwards from the community. We aim to strike a balance of what would work best for 80% of customers. Emerging practices are considered and discussed via Requests for Comment (RFCs)
• Progressive. Utilities are designed to be incrementally adoptable for customers at any stage of their Serverless journey. They follow language idioms and their community’s common practices.

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Last update: 2023-02-15