Development & Testing

tRPC Type-Safe APIs

Build fully type-safe APIs without schemas or code generation using tRPC, sharing types directly between server and client.

Claude Code Codex Copilot Cursor Windsurf

Overview

tRPC enables you to build fully type-safe APIs by leveraging TypeScript's type inference to share types between your server and client without any code generation step. When you change a server procedure, your client code gets immediate type errors if it's incompatible. This makes it perfect for AI agents because the TypeScript compiler catches mistakes instantly.

Your AI agent can define routers with input validation (using Zod), create queries and mutations, set up context for authentication, and implement middleware for logging or rate limiting. The procedure definitions are just functions, so the agent can work with them as naturally as any other TypeScript code. No SDL, no codegen, no separate API documentation to maintain.

tRPC integrates seamlessly with Next.js (App Router and Pages Router), Express, Fastify, and other frameworks. It supports subscriptions for real-time features, batch requests for performance, and React Query integration for client-side caching. Your AI agent can scaffold entire API layers in minutes with full end-to-end type safety.

Who Is This For?

Next.js developers building full-stack applications with end-to-end type safety
Teams that want API type safety without the overhead of GraphQL schemas
Developers building internal tools where client and server share a codebase
Startups prototyping quickly with type-safe APIs and zero boilerplate

Installation

Setup for Claude Code

npm install @trpc/server @trpc/client @trpc/react-query zod
Claude Code generates routers, procedures, and client hooks

Configuration

// src/server/trpc.ts
import { initTRPC } from "@trpc/server";
import { z } from "zod";

const t = initTRPC.create();
export const router = t.router;
export const publicProcedure = t.procedure;

export const appRouter = router({
  hello: publicProcedure
    .input(z.object({ name: z.string() }))
    .query(({ input }) => `Hello ${input.name}`),
});
export type AppRouter = typeof appRouter;