tRPC Full-Stack

Overview

tRPC lets you build fully type-safe APIs without writing a schema or code-generation step. Your TypeScript types flow from the server router directly to the client — so every API call is autocompleted, validated at compile time, and refactoring-safe. Use this skill when building TypeScript monorepos, Next.js apps, or any project where the server and client share a codebase.

When to Use This Skill

• Use when building a TypeScript full-stack app (Next.js, Remix, Express + React) where the client and server share a single repo
• Use when you want end-to-end type safety on API calls without REST/GraphQL schema overhead
• Use when adding real-time features (subscriptions) to an existing tRPC setup
• Use when designing multi-step middleware (auth, rate limiting, tenant scoping) on tRPC procedures
• Use when migrating an existing REST/GraphQL API to tRPC incrementally

Examples require matching tRPC/TanStack Query versions and application-specific auth, database models and user/session types. Cron jobs cannot assume request-bound auth() exists: build an explicitly authorized service context. The shown subscription router also needs root registration, a transport adapter and client link; its process-local emitter does not distribute across replicas. HTTP GET/POST handlers do not alone provide WebSockets. Type safety is not authorization: scope queries/output fields to permitted records, handle CSRF/origin for cookie-authenticated mutations, and enforce ownership atomically with writes.

Core Concepts

Routers and Procedures