AWS CDK Development
This skill provides comprehensive guidance for developing AWS infrastructure using the Cloud Development Kit (CDK), with integrated MCP servers for accessing latest AWS knowledge and CDK utilities.
AWS Documentation Requirement
CRITICAL: This skill requires AWS MCP tools for accurate, up-to-date AWS information.
Before Answering AWS Questions
Always verify using AWS MCP tools (if available):
mcp__aws-mcp__awssearchdocumentation or mcpawsdocsaws___search_documentation - Search AWS docs mcp__aws-mcp__aws___read_documentation or mcpawsdocs__awsreaddocumentation - Read specific pages mcpaws-mcp__aws___get_regional_availability - Check service availability
If AWS MCP tools are unavailable:
Guide user to configure AWS MCP using the aws-mcp-setup skill (auto-loaded as dependency) Help determine which option fits their environment: Has uvx + AWS credentials → Full AWS MCP Server No Python/credentials → AWS Documentation MCP (no auth) If cannot determine → Ask user which option to use Integrated MCP Servers
This skill includes the CDK MCP server automatically configured with the plugin:
AWS CDK MCP Server
When to use: For CDK-specific guidance and utilities
Get CDK construct recommendations Retrieve CDK best practices Access CDK pattern suggestions Validate CDK configurations Get help with CDK-specific APIs
Important: Leverage this server for CDK construct guidance and advanced CDK operations.
When to Use This Skill
Use this skill when:
Creating new CDK stacks or constructs Refactoring existing CDK infrastructure Implementing Lambda functions within CDK Following AWS CDK best practices Validating CDK stack configurations before deployment Verifying AWS service capabilities and regional availability Core CDK Principles Resource Naming
CRITICAL: Do NOT explicitly specify resource names when they are optional in CDK constructs.
Why: CDK-generated names enable:
Reusable patterns: Deploy the same construct/pattern multiple times without conflicts Parallel deployments: Multiple stacks can deploy simultaneously in the same region Cleaner shared logic: Patterns and shared code can be initialized multiple times without name collision Stack isolation: Each stack gets uniquely identified resources automatically
Pattern: Let CDK generate unique names automatically using CloudFormation's naming mechanism.
// ❌ BAD - Explicit naming prevents reusability and parallel deployments new lambda.Function(this, 'MyFunction', { functionName: 'my-lambda', // Avoid this // ... });
// ✅ GOOD - Let CDK generate unique names new lambda.Function(this, 'MyFunction', { // No functionName specified - CDK generates: StackName-MyFunctionXXXXXX // ... });
Security Note: For different environments (dev, staging, prod), follow AWS Security Pillar best practices by using separate AWS accounts rather than relying on resource naming within a single account. Account-level isolation provides stronger security boundaries.
Lambda Function Development
Use the appropriate Lambda construct based on runtime:
TypeScript/JavaScript: Use @aws-cdk/aws-lambda-nodejs
import { NodejsFunction } from 'aws-cdk-lib/aws-lambda-nodejs';
new NodejsFunction(this, 'MyFunction', { entry: 'lambda/handler.ts', handler: 'handler', // Automatically handles bundling, dependencies, and transpilation });
Python: Use @aws-cdk/aws-lambda-python
import { PythonFunction } from '@aws-cdk/aws-lambda-python-alpha';
new PythonFunction(this, 'MyFunction', { entry: 'lambda', index: 'handler.py', handler: 'handler', // Automatically handles dependencies and packaging });
Benefits:
Automatic bundling and dependency management Transpilation handled automatically No manual packaging required Consistent deployment patterns Pre-Deployment Validation
Use a multi-layer validation strategy for comprehensive CDK quality checks:
Layer 1: Real-Time IDE Feedback (Recommended)
For TypeScript/JavaScript projects:
Install cdk-nag for synthesis-time validation:
npm install --save-dev cdk-nag
Add to your CDK app:
import { Aspects } from 'aws-cdk-lib'; import { AwsSolutionsChecks } from 'cdk-nag';
const app = new App(); Aspects.of(app).add(new AwsSolutionsChecks());
Optional - VS Code users: Install CDK NAG Validator extension for faster feedback on file save.
For Python/Java/C#/Go projects: cdk-nag is available in all CDK languages and provides the same synthesis-time validation.
Layer 2: Synthesis-Time Validation (Required)
Synthesis with cdk-nag: Validate stack with comprehensive rules
cdk synth # cdk-nag runs automatically via Aspects
Suppress legitimate exceptions with documented reasons:
import { NagSuppressions } from 'cdk-nag';
// Document WHY the exception is needed NagSuppressions.addResourceSuppressions(resource, [ { id: 'AwsSolutions-L1', reason: 'Lambda@Edge requires specific runtime for CloudFront compatibility' } ]);
Layer 3: Pre-Commit Safety Net
Build: Ensure compilation succeeds
npm run build # or language-specific build command
Tests: Run unit and integration tests
npm test # or pytest, mvn test, etc.
Validation Script: Meta-level checks
./scripts/validate-stack.sh
The validation script now focuses on:
Language detection Template size and resource count analysis Synthesis success verification (Note: Detailed anti-pattern checks are handled by cdk-nag) Workflow Guidelines Development Workflow Design: Plan infrastructure resources and relationships Verify AWS Services: Use AWS Documentation MCP to confirm service availability and features Check regional availability for all required services Verify service limits and quotas Confirm latest API specifications Implement: Write CDK constructs following best practices Use CDK MCP server for construct recommendations Reference CDK best practices via MCP tools Validate: Run pre-deployment checks (see above) Synthesize: Generate CloudFormation templates Review: Examine synthesized templates for correctness Deploy: Deploy to target environment Verify: Confirm resources are created correctly Stack Organization Use nested stacks for complex applications Separate concerns into logical construct boundaries Export values that other stacks may need Use CDK context for environment-specific configuration Testing Strategy Unit test individual constructs Integration test stack synthesis Snapshot test CloudFormation templates Validate resource properties and relationships Using MCP Servers Effectively When to Use AWS Documentation MCP
Always verify before implementing:
New AWS service features or configurations Service availability in target regions API parameter specifications Service limits and quotas Security best practices for AWS services
Example scenarios:
"Check if Lambda supports Python 3.13 runtime" "Verify DynamoDB is available in eu-south-2" "What are the current Lambda timeout limits?" "Get latest S3 encryption options" When to Use CDK MCP Server
Leverage for CDK-specific guidance:
CDK construct selection and usage CDK API parameter options CDK best practice patterns Construct property configurations CDK-specific optimizations
Example scenarios:
"What's the recommended CDK construct for API Gateway REST API?" "How to configure NodejsFunction bundling options?" "Best practices for CDK stack organization" "CDK construct for DynamoDB with auto-scaling" MCP Usage Best Practices Verify First: Always check AWS Documentation MCP before implementing new features Regional Validation: Check service availability in target deployment regions CDK Guidance: Use CDK MCP for construct-specific recommendations Stay Current: MCP servers provide latest information beyond knowledge cutoff Combine Sources: Use both skill patterns and MCP servers for comprehensive guidance CDK Patterns Reference
For detailed CDK patterns, anti-patterns, and architectural guidance, refer to the comprehensive reference:
File: references/cdk-patterns.md
This reference includes:
Common CDK patterns and their use cases Anti-patterns to avoid Security best practices Cost optimization strategies Performance considerations Additional Resources Validation Script: scripts/validate-stack.sh - Pre-deployment validation CDK Patterns: references/cdk-patterns.md - Detailed pattern library AWS Documentation MCP: Integrated for latest AWS information CDK MCP Server: Integrated for CDK-specific guidance GitHub Actions Integration
When GitHub Actions workflow files exist in the repository, ensure all checks defined in .github/workflows/ pass before committing. This prevents CI/CD failures and maintains code quality standards.