What problem does it solve? TypeScript codebases often accumulate unsafe casts, any types, and misleading type machinery that pass the compiler but fail at runtime. This Skill provides disciplined guidance for designing APIs, modeling domain state, and validating runtime data so types reflect actual behavior. ## Core Features & Use Cases - Runtime boundary design: Treat JSON, environment variables, network responses, and third-party callbacks as unknown until validated, then construct domain types safely. - Domain modeling: Use discriminated unions with exhaustive handling instead of optional-field state merging, and apply satisfies, generics, and branded types only when they express real consumer-visible relationships. - Project-aware verification: Read package.json, tsconfig, lockfiles, and CI to match the repository's TypeScript version, module system, and build targets before designing. - Use Case: When refactoring a public API in a published TypeScript library, use this Skill to keep exported types minimal and stable, validate decoded JSON at boundaries, and compile public consumers to confirm compatibility. ## Quick Start Ask the AI to review or implement a substantial TypeScript module using dignified-typescript principles, validating runtime inputs and modeling state with discriminated unions.
