| description | Use when implementing TypeScript code requiring advanced type system patterns, complex generics, type-level programming, or end-to-end type safety across full-stack applications. Specifically:\n\n<example>\nContext: Building an API client library that needs maximum type safety with generic request/response handling and discriminated unions for different API outcomes\nuser: "Create a type-safe API client library using TypeScript where callers get full type inference for requests and responses without casting. Need conditional types based on method names and discriminated unions for success/error responses."\nassistant: "I'll design a type-driven API client using advanced TypeScript features: generic constraints for request/response pairs, conditional types to infer response shapes based on endpoint, discriminated unions for Result<Success, Error> patterns, and type-safe builder for requests. This ensures zero-runtime type errors and full IDE autocomplete."\n<commentary>\nUse typescript-pro when building libraries, frameworks, or critical application code that demands advanced type patterns like conditional types, mapped types, template literal types, or type-level programming to prevent runtime errors through compile-time guarantees.\n</commentary>\n</example>\n\n<example>\nContext: Migrating a large monorepo from JavaScript to TypeScript with existing codebase, requiring graduated strict mode rollout and maximum type coverage without breaking changes\nuser: "We need to gradually migrate our 500k LOC JavaScript monorepo to TypeScript. Can't do it all at once. Need strategy for tsconfig setup with project references, incremental compilation, type coverage tracking, and handling legacy JS interop."\nassistant: "I'll architect a multi-phase migration: set up tsconfig with project references for isolated compilation, establish type coverage metrics and CI checks, implement type-only exports to prevent dependency bloat, configure allowJs/checkJs for gradual enforcement, and create migration guides for team onboarding."\n<commentary>\nInvoke typescript-pro for large-scale TypeScript adoption, complex build optimization, monorepo TypeScript architecture, or when you need sophisticated type system patterns beyond what standard TypeScript setup provides.\n</commentary>\n</example>\n\n<example>\nContext: Full-stack application needs end-to-end type safety with shared types between Next.js frontend and tRPC backend, with code generation from database schema\nuser: "Set up full end-to-end type safety in our Next.js + tRPC stack. Want database schema types generated and shared with API layer, then validated at API boundary, with frontend getting full type inference without any type assertions."\nassistant: "I'll implement e2e type safety: generate TypeScript types from database schema using Prisma, use tRPC's type-safe routers for API contracts, configure strict TypeScript settings across frontend/backend, set up type tests for public APIs, and ensure all types flow from database through backend to frontend with zero runtime gaps."\n<commentary>\nUse typescript-pro when architecting end-to-end type-safe systems spanning multiple layers, integrating code generation with type systems, or requiring sophisticated type sharing between frontend and backend to eliminate type mismatches at runtime.\n</commentary>\n</example> |
