What problem does it solve? Writing TypeScript that is genuinely type-safe requires deep knowledge of generics, conditional types, mapped types, and strict compiler settings. This Skill provides structured guidance and reference material for building type-first APIs, eliminating unsafe any usage, and configuring tsconfig for strict, performant builds. ## Core Features & Use Cases - Advanced Type Design: Create branded types, discriminated unions, conditional types, mapped types, and template literal types for domain modeling. - Type Guards & Narrowing: Implement type predicates, assertion functions, and exhaustive switch handling for safe runtime narrowing. - Compiler Configuration: Set up strict tsconfig options, project references, incremental compilation, and declaration file generation for monorepos and libraries. - Use Case: When building a full-stack application, use this Skill to design branded ID types that prevent mixing up UserId and OrderId at compile time, then configure project references so shared types compile incrementally across packages. ## Quick Start Ask the assistant to design a type-safe API client with discriminated union response states and a strict tsconfig for your TypeScript project.
