aws-cdk
Authors, deploys, and troubleshoots AWS infrastructure using CDK with TypeScript or Python. Covers best practices, stack architecture, and construct patterns. Applies when writing CDK constructs, bootstrapping environments, running cdk deploy/synth/diff, fixing CDK or CloudFormation errors, planning stack structure, importing existing resources, resolving drift, or refactoring stacks without resource replacement.
Overview
AWS CDK
Overview
Domain expertise for CDK construct authoring, deployment workflows, compliance, drift, importing resources, safe refactoring, and troubleshooting CDK CLI / CloudFormation errors.
When NOT to use: Raw CloudFormation YAML/JSON. SAM. Terraform/Pulumi. CI/CD beyond CDK Pipelines. Use builtin knowledge or specialized skills for these.
Critical Warnings
Deadly embrace: Removing a cross-stack reference deadlocks deployment (Export ... cannot be deleted as it is in use by ...). Preferred fix: weaken the reference first — CrossStackReferences.of($RESOURCE).produce(ReferenceStrength.BOTH) then WEAK, then remove (three deploys). Legacy fallback: two-deploy this.exportValue() recipe. See troubleshooting-deployment.
Construct ID changes cause replacement: Renaming/moving a construct changes its logical ID → CloudFormation replaces the resource (data loss for stateful resources). Always cdk diff before deploy. See refactor-and-prevent-replacement.
UPDATE_ROLLBACK_FAILED: Stack is stuck. Fix with cdk rollback $STACK or cdk rollback $STACK --orphan <LogicalId>. Express mode stacks are the exception — they cannot be rolled back at all. See troubleshooting-deployment.
Hotswap and express mode are development-only: --hotswap / --hotswap-fallback bypass CloudFormation and create drift on purpose; --express reports success before resources stabilize and disables automatic rollback. You MUST NOT use either in production. A failed --express deployment cannot be rolled back — recover by rolling forward with another --express deploy. See fast-deployments.
Non-empty S3 buckets persist after destroy: You MUST set both removalPolicy: DESTROY and autoDeleteObjects: true. Versioned buckets are worse — delete markers persist even after apparent deletion.
Common Workflows
| Task | Quick Command | Details |
|---|---|---|
| Bootstrap | cdk bootstrap aws://$ACCOUNT/$REGION | bootstrap-and-project-setup |
| New TS project | cdk init app --language typescript — use tsx, eslint-plugin-awscdk | bootstrap-and-project-setup |
| New Python project | cdk init app --language python — pin deps, use virtualenv | bootstrap-and-project-setup |
| Deploy | cdk synth --strict → cdk diff → cdk deploy | Always diff before deploy to production |
| Fast dev iteration | cdk deploy --hotswap-fallback, cdk watch, or cdk deploy --express — dev only, never production | fast-deployments |
| cdk-nag | Aspects.of(app).add(new AwsSolutionsChecks()) | compliance-and-drift |
| Drift | cdk drift $STACK (use --fail in CI) | compliance-and-drift |
| Import resource | cdk import (interactive or --resource-mapping for CI), cdk deploy --import-existing-resources | import-and-migrate |
| Refactor safely | cdk refactor --unstable=refactor — no property changes in same deploy | refactor-and-prevent-replacement |
Fast Deployments — Hotswap vs Express (dev only)
Both trade safety for speed and you MUST NOT use either in production.
Choosing between them: Use --hotswap / --hotswap-fallback for the fastest loop when you work mostly with hotswappable resources and drift does not matter. Use --express when drift is unacceptable, or your resources are not hotswappable.
Recovery workflows (hotswap drift via --revert-drift, rolling a failed --express deploy forward), the hotswappable-resource rules, and IAM/monitoring enforcement of the prod prohibition are all in the full guide: fast-deployments.
Troubleshooting
| Error | Cause → Fix |
|---|---|
| DeployFailed / DeploymentError | CDK error isn't the root cause. cdk deploy $STACK --verbose, then cdk --unstable=diagnose diagnose $STACK (CLI ≥ 2.1120.0); else aws cloudformation describe-events --stack-name $STACK --filters FailedEvents=true — the first _FAILED event is the cause. Details |
| NoCredentials / ExpiredToken / AssumeRoleFailed | aws sts get-caller-identity + cdk doctor. Expired SSO, missing env, missing sts:AssumeRole. Details |
| Asset errors (CannotFindAsset, FailedToBundleAsset, AssetBuildFailed, AssetPublishFailed) | Path wrong, Docker not running, or bootstrap bucket perms. Use path.join(__dirname, ...). Details |
| AppRequired | Add "app": "npx tsx bin/my-app.ts" to cdk.json. Details |
| AnnotationErrors | Fix the underlying issue; suppress with NagSuppressions only as last resort. Details |
| ConcurrentReadLock / ConcurrentWriteLock | rm -rf cdk.out then re-run. Parallel CI: --output ./cdk.out.$BUILD_ID. Details |
| BootstrapVersionValidation | Re-bootstrap. Match --qualifier everywhere. Details |
| DependencyCycle | Extract shared resource into third stack or use SSM for late-binding. Details |
| UnresolvedAccount | Set explicit env: { account, region } on stack. Commit cdk.context.json. Details |
| NoStacksMatched | CDK uses logical ID (2nd constructor arg), not CFN name. cdk list to find IDs. Details |
| Cannot find module (synth time) | Run npx tsc --noEmit, check cdk.json app path matches tsconfig.json outDir, delete stale .js files. Python: activate venv. Details |
| V1 import paths / duplicate aws-cdk-lib | V1 @aws-cdk/* imports, wrong Construct import, duplicate lib copies in monorepos. Details |
| Lambda Cannot find module (runtime) | Wrong handler value, missing AWS SDK v3 migration, Python deps not bundled. Details |
| API Gateway multi-stage conflicts | Set deploy: false on RestApi, create Deployment and Stage explicitly. Details |
Change didn't deploy under --hotswap | Changes to non-hotswappable resources are silently ignored and only logged — the command still reports success. Read the output; use --hotswap-fallback to force a CloudFormation deployment instead. Details |
Failed --express deploy / can't roll back | Express mode cannot use the Rollback Stack API, and a standard deploy MUST NOT be used to recover it. Roll forward: fix the cause, then cdk deploy $STACK --express. Details |
| Unexpected drift on a dev stack | Hotswap and cdk watch create drift by design. Until reverted, the live resources — not CloudFormation's records — are authoritative. Reconcile with cdk deploy $STACK --revert-drift, which uses Drift Aware Changesets to bring live resources in line with the template (updates reality to match desired state; does NOT rewrite CF records to match drifted resources). Details |
Construct Patterns
Prefer L2. Use L1 with Mixins/Facades when L2 lacks a property. Escape hatches: node.defaultChild → addPropertyOverride. See construct-patterns.
Additional Resources
- Search AWS documentation for "CDK Developer Guide", "CDK API Reference" and "CDK Pipelines" respectively
Security Considerations
- OIDC for CI/CD credentials (no static keys)
--custom-permissions-boundaryon bootstrapgrant*()for inter-resource IAMcdk-nag+--strictin CI- Stateful resources in own stack with
terminationProtection: true - Commit
cdk.context.json
Files 11 files
- SKILL.mdMarkdown
- references/bootstrap-and-project-setup.mdMarkdown
- references/compliance-and-drift.mdMarkdown
- references/construct-patterns.mdMarkdown
- references/fast-deployments.mdMarkdown
- references/import-and-migrate.mdMarkdown
- references/refactor-and-prevent-replacement.mdMarkdown
- references/troubleshooting-credentials.mdMarkdown
- references/troubleshooting-deployment.mdMarkdown
- references/troubleshooting-synth.mdMarkdown
- references/v1-to-v2-migration.mdMarkdown
Install it by hand
Deska runs this for you, for every agent you pick. To run it yourself in a terminal:
npx skills add aws/agent-toolkit-for-aws --skill aws-cdkMore from aws
- aws-iamawsProvides verified corrections for IAM behaviors that AI agents frequently get wrong — policy evaluation edge cases, trust policy gotchas, STS session limits, Organizations quirks, and SAML/MFA specifics. Also provides structured workflows for IAM role management and baseline policy generation from application source code or a Terraform plan JSON. Covers condition operator safety (ForAnyValue/ForAllValues with Null checks), bucket policy deny patterns (VPC endpoint restrictions, org paths), confused deputy protection, and service role creation for AWS services (Glue, CloudTrail, Lambda, ECS, etc.) with aws:SourceAccount/aws:SourceArn trust conditions. Applies when creating IAM roles, writing IAM or bucket policies, generating policies from application source code or a Terraform plan JSON, working with STS, Organizations, or condition operators, or any task needing a service or execution role. Does not cover non-IAM authorization like Cognito user-pool policies or app-level RBAC.9,200 installs on skills.sh0
- aws-serverlessawsBuilds, deploys, manages, debugs, configures, and optimizes serverless applications on AWS using Lambda, API Gateway, Step Functions, EventBridge, and SAM/CDK. Covers cold starts, CORS debugging, event source mappings, troubleshooting, concurrency, SnapStart, Powertools, function URLs, EventBridge Scheduler, Lambda layers, and production readiness. Triggers on mentions of Lambda, API Gateway, Step Functions, SAM templates, CDK serverless stacks, DynamoDB stream triggers, SQS event sources, cold starts, timeouts, 502/504 errors, throttling, concurrency, CORS, Powertools, or any event-driven architecture on AWS, even without the word "serverless." Does not apply to EC2, ECS/Fargate containers, or Amplify hosting.9,000 installs on skills.sh0
- aws-observabilityawsBuilds, configures, debugs, and optimizes AWS observability - operator-symptom questions and detecting Omni vs classic CloudWatch. CloudWatch on an already-reporting service: Log Insights, metric/composite/anomaly alarms, custom metrics/EMF, dashboards, X-Ray/ADOT tracing, canaries, CloudTrail, Dynamic Instrumentation (live breakpoints/snapshots), the Application Signals service map, and fleet health views. CloudWatch Omni on an existing Space: SQL over logs and traces, PromQL over metrics, Omni dashboards, Omni alerts, context graph for root cause, programmatic/IaC access (API/SDK/CLI/CloudFormation), driving Omni from a coding agent or skills, and evaluating AI agent quality from traces - on-demand and online scoring of live traffic, readback, custom evaluators. For first-time setup - creating an Omni Space, granting access, ingestion, or ADOT instrumentation for Application Signals (ServiceEvents, CI/CD metadata) or Omni - use setting-up-cloudwatch-observability. Not for app logging or threat detection.8,900 installs on skills.sh0
- aws-containersawsBuilds and deploys containerized workloads on Elastic Kubernetes Service (EKS), Elastic Container Service (ECS), Fargate, and ECR (Elastic Container Registry). Covers general EKS knowledge, Karpenter, AWS Load Balancer Controller and leveraging various open source Kubernetes projects with EKS. Covers general ECS knowledge, task definitions, Fargate services, ECS Exec, ECS Express Mode and ECS Managed Instances. Covers general Elastic Beanstalk knowledge, Elastic Beanstalk configuration and platforms supported by Elastic Beanstalk. Covers general ECR knowledge, ECR repository setup and lifecycle policies. Includes recommending, enabling, and reading Amazon ECS Action Logs to troubleshoot control-plane failures (deployment rollback/circuit-breaker, task placement, scaling, task replacement). Applies when deploying, debugging, or optimizing containers on AWS. Should be used instead of relying on internal knowledge for these services.8,300 installs on skills.sh0
- aws-billing-and-cost-managementawsAnalyze AWS costs, find savings, manage budgets, evaluate Savings Plans and Reserved Instances, right-size EC2/Lambda/RDS/EBS with Compute Optimizer, look up service pricing, query CUR with Athena, detect cost anomalies, scope costs to billing views, and monitor Free Tier usage. Triggers on: AWS bill, cost analysis, reduce spend, savings plan, reserved instance, right-size, budget alert, cost optimization, pricing, free tier, cost anomaly, CUR, cost audit, billing view, billing view ARN.8,000 installs on skills.sh0
