Container Tool Kit (CTK) is a full-stack web application for visually building and editing Docker Compose and Kubernetes manifests. It provides a node-based canvas (using jsPlumb) where users can create services, volumes, and networks, connect them to represent dependencies and mounts, and see a live YAML/JSON preview via Monaco editor. The system supports importing existing manifests (Compose or Kubernetes), validating them against pinned schemas, and exporting the final output. The backend (FastAPI + PostgreSQL) handles user authentication (email/password, GitHub OAuth), project persistence, and encrypted private variable management. The frontend is a React SPA with TypeScript, Tailwind CSS, and shadcn/ui components. The architecture is a typical SPA + REST API, with the frontend handling all manifest generation and validation logic client-side, while the backend provides persistence and authentication. The codebase demonstrates strong engineering practices with extensive test coverage for manifest round-tripping, form preservation, and canvas state management. Notable reusable components include a declarative form system (SuperForm), a pure graph state module, and a comprehensive manifest validation pipeline with structured diagnostics and user-suppressible exclusions.