@trpc/server

tRPC enables you to build fully typesafe APIs without schemas or code generation by leveraging TypeScript's type inference to share types between server and client automatically. With tRPC, you define procedures (queries, mutations, subscriptions) on the server using a fluent builder API, and the client automatically knows the input types, output types, and available endpoints without any manual type definitions or code generation step. This eliminates the entire category of API contract bugs where client and server disagree on request or response shapes. tRPC supports input validation using Zod, Yup, or any validation library, middleware for authentication and authorization, context creation for per-request data like user sessions, and subscriptions for real-time updates. The framework integrates with Next.js, Express, Fastify, and standalone Node.js servers, with React Query integration providing automatic caching, invalidation, and optimistic updates on the client. tRPC is particularly powerful in monorepo setups where server and client share a TypeScript codebase, enabling the fastest possible iteration speed for full-stack TypeScript applications.