Why We Migrated from REST to tRPC

Building full-stack TypeScript applications often leads to duplicate effort: maintaining backend schemas, regenerating OpenAPI specs, and manually writing client-side fetch types.

Moving our internal dashboard to tRPC removed this glue code entirely by sharing types directly between client and server.

The Problem with Manual Contracts

In a standard setup, backend changes can quietly desynchronize from the client until a runtime error occurs:

• Type Drift: Backend modifies a response field, but frontend interfaces remain stale.
• Boilerplate Fatigue: Maintaining DTOs, Zod schemas, and client SDKs across separate repositories.
• Over-fetching: Rigid REST endpoints serving unnecessary nested payloads.

Code Comparison

Instead of manually typing fetch calls and route handlers:

// server/routers/user.ts
import { router, publicProcedure } from '../trpc';
import { z } from 'zod';

export const userRouter = router({
  getById: publicProcedure
    .input(z.object({ id: z.string() }))
    .query(async ({ input, ctx }) => {
      const user = await ctx.db.user.findUnique({
        where: { id: input.id },
        select: { id: true, name: true, email: true },
      });
      return user;
    }),
});

export type AppRouter = typeof userRouter;