powertools-aws

name	powertools-aws
description	ALWAYS use this skill when writing AWS Lambda functions in Python, TypeScript, Java, or .NET. Provides serverless best practices for structured logging, distributed tracing (X-Ray), CloudWatch metrics, idempotency, batch processing, and event handling using Powertools for AWS Lambda. Essential for any Lambda development.
license	MIT
metadata	{"author":"aws-powertools","repository":"https://github.com/aws-powertools","runtimes":"python, typescript, java, dotnet"}

Powertools for AWS Lambda

A developer toolkit to implement Serverless best practices and increase developer velocity across Python, TypeScript, Java, and .NET Lambda runtimes.

Invoke This Skill When

• Writing or modifying AWS Lambda functions
• User mentions "serverless" with Python, TypeScript, Java, or .NET
• Implementing structured logging in Lambda
• Adding distributed tracing (AWS X-Ray)
• Creating CloudWatch custom metrics or Datadog metrics
• Handling SQS, Kinesis, or DynamoDB Streams batch processing
• Implementing idempotency patterns
• Building REST or GraphQL APIs with Lambda
• Building AppSync resolvers or event handlers
• Creating Amazon Bedrock Agents with Lambda
• Processing Kafka events (MSK, self-managed)
• User mentions Powertools, aws-lambda-powertools, or @aws-lambda-powertools
• Working with SAM, CDK, or Serverless Framework templates
• Needing to parse/validate Lambda event payloads
• Implementing feature flags or data masking

Documentation Sources (llms.txt)

CRITICAL: Before implementing any Powertools feature, fetch the llms.txt for the target runtime. These files contain the authoritative, up-to-date documentation index.

Runtime	llms.txt URL	Package
Python	https://docs.aws.amazon.com/powertools/python/latest/llms.txt	aws-lambda-powertools
TypeScript	https://docs.aws.amazon.com/powertools/typescript/latest/llms.txt	@aws-lambda-powertools/*
Java	https://docs.aws.amazon.com/powertools/java/latest/llms.txt	software.amazon.lambda:powertools-*
.NET	https://docs.aws.amazon.com/powertools/dotnet/llms.txt	AWS.Lambda.Powertools.*

Note: .NET does not use /latest/ in its URL path.

How to Use Documentation

1. Identify the runtime from file extensions or user request
2. Fetch the llms.txt for that runtime
3. Find the relevant section (e.g., Logger, Metrics, Batch)
4. Fetch the specific doc page (URLs in llms.txt point to .md files)
5. Apply the patterns from the documentation

Runtime Detection

File Pattern	Runtime
*.py with def handler(event, context)	Python
*.ts or *.js with export const handler	TypeScript
*.java with handleRequest method	Java
*.cs with FunctionHandler	.NET
template.yaml / samconfig.toml	Check Runtime property
serverless.yml	Check provider.runtime
cdk.json / *.cdk.ts	Check runtime in Lambda construct

Core Utilities Overview

All runtimes provide these core utilities:

Utility	Purpose	When to Use
Logger	Structured JSON logging with Lambda context	Every Lambda - always add logging
Tracer	AWS X-Ray distributed tracing	Debugging, performance analysis, service maps
Metrics	CloudWatch Embedded Metric Format (EMF)	Monitoring, alerting, dashboards

Additional Utilities (varies by runtime)

Utility	Python	TypeScript	Java	.NET	Purpose
Idempotency	Y	Y	Y	Y	Prevent duplicate processing
Batch Processing	Y	Y	Y	Y	Handle partial failures (SQS/Kinesis/DynamoDB)
Parameters	Y	Y	Y	Y	SSM/Secrets Manager with caching
Kafka Consumer	Y	Y	Y	Y	Kafka event deserialization (Avro, Protobuf, JSON Schema)
JMESPath Functions	Y	Y	-	Y	Extract/deserialize nested JSON payloads
Parser/Validation	Y	Y	Y	-	Event validation and parsing (Pydantic/Standard Schema)
Event Handler: REST API	Y	Y	-	-	API Gateway, ALB, Lambda Function URL
Event Handler: GraphQL	Y	Y	-	-	AppSync GraphQL resolvers
Event Handler: AppSync Events	Y	Y	-	Y	AppSync real-time event handlers
Event Handler: Bedrock Agents	Y	Y	-	Y	Amazon Bedrock Agent function resolvers
Feature Flags	Y	-	-	-	Runtime feature toggling with AppConfig
Streaming	Y	-	-	-	Process large S3 objects/datasets
Data Masking	Y	-	-	-	Encrypt/mask sensitive data fields
Event Source Data Classes	Y	-	-	-	Typed classes for Lambda event sources
Typing	Y	-	-	-	Static typing for Lambda context
Middleware Factory	Y	-	-	-	Create custom middleware decorators
Datadog Metrics	Y	-	-	-	Alternative metrics provider for Datadog
Custom Resources	-	-	Y	-	CloudFormation custom resource handlers
Large Messages	-	-	Y	-	Handle messages >256KB via S3
Serialization	-	-	Y	-	JSON serialization utilities