Iac Scaffold

Scaffold a new AWS IaC project.

Framework: $ARGUMENTS[0] (cdk, terraform, sam, or cfn) Description: $ARGUMENTS[1]

Process

1. Ask clarifying questions if the framework or description is unclear 2. Use the aws-iac MCP tools to validate resource configurations and check for security issues 3. Use the awsknowledge MCP tools (mcp__plugin_aws-dev-toolkit_awsknowledge__aws___search_documentation, mcp__plugin_aws-dev-toolkit_awsknowledge__aws___read_documentation, mcp__plugin_aws-dev-toolkit_awsknowledge__aws___recommend) to look up current best practices for the chosen framework 4. Generate the project structure following the patterns in templates/

Framework-Specific Guidance

CDK (TypeScript default)

• Use cdk init app --language typescript patterns
• Separate stacks by lifecycle (networking, data, compute)
• Use cdk-nag for compliance checks
• Outputs for cross-stack references

Terraform

• Module-per-service structure
• Remote state in S3 + DynamoDB locking
• Use terraform-aws-modules where they exist
• Separate tfvars per environment

SAM

• template.yaml at root
• Globals section for shared Lambda config
• Use SAM Accelerate for fast iteration

CloudFormation

• Nested stacks for reuse
• Parameters with AllowedValues for guardrails
• Conditions for multi-environment templates

Gotchas

• Always include a .gitignore appropriate for the framework
• CDK: don't put secrets in context — use SSM Parameter Store or Secrets Manager
• Terraform: never commit .tfstate — configure remote backend first
• SAM: sam local needs Docker — mention this in the README
• All frameworks: tag everything with at minimum Environment, Project, Owner
• Include a Makefile or justfile with common commands (deploy, destroy, diff, synth)

Output

Generate the complete project structure with: 1. Entry point / main config file 2. At least one example resource 3. Environment-specific configuration 4. README with setup instructions 5. CI/CD pipeline config (GitHub Actions default, ask if different)

CDK Project Structure Pattern

my-cdk-app/
├── bin/
│   └── app.ts                 # App entry point, stack instantiation
├── lib/
│   ├── networking-stack.ts    # VPC, subnets, security groups
│   ├── data-stack.ts          # Databases, caches, storage
│   └── compute-stack.ts       # Lambda, ECS, API Gateway
├── test/
│   └── *.test.ts              # Snapshot + fine-grained assertion tests
├── cdk.json                   # CDK config
├── tsconfig.json
├── package.json
├── Makefile                   # deploy, diff, synth, destroy shortcuts
└── README.md

Key Conventions

• One stack per lifecycle boundary (networking changes rarely, compute changes often)
• Cross-stack references via stack outputs, not hardcoded ARNs
• Use cdk-nag in test suite for compliance
• Environment config via CDK context (cdk.json or -c flags), not env vars
• Tag all resources: Tags.of(app).add('Project', 'my-project')

IaC Scaffold Templates

This directory contains reference patterns for each supported framework. Claude reads these when scaffolding new projects.

Frameworks

• cdk/: CDK TypeScript project structure patterns
• terraform/: Terraform module structure patterns
• sam/: SAM application patterns
• cfn/: CloudFormation template patterns

These are reference files, not runnable templates. They show Claude the expected structure and conventions for each framework.

Terraform Project Structure Pattern

my-terraform-project/
├── main.tf                    # Provider config, module calls
├── variables.tf               # Input variables
├── outputs.tf                 # Stack outputs
├── versions.tf                # Required providers and versions
├── backend.tf                 # Remote state config (S3 + DynamoDB)
├── modules/
│   ├── networking/            # VPC, subnets, security groups
│   │   ├── main.tf
│   │   ├── variables.tf
│   │   └── outputs.tf
│   └── compute/               # Lambda, ECS, etc.
│       ├── main.tf
│       ├── variables.tf
│       └── outputs.tf
├── environments/
│   ├── dev.tfvars
│   ├── staging.tfvars
│   └── prod.tfvars
├── Makefile                   # plan, apply, destroy per environment
└── README.md

Key Conventions

• Pin provider versions in versions.tf
• Remote state in S3 with DynamoDB locking from day one
• One module per logical grouping, not per resource
• Use terraform-aws-modules for common patterns (VPC, EKS, etc.)
• terraform fmt and terraform validate in CI
• Tag all resources via default_tags in provider block