tRPC vs GraphQL Comparison

// tRPC — router definition (server)
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
// db = your Prisma/ORM client (imported from a separate file)

const t = initTRPC.create();

export const appRouter = t.router({
  getUser: t.procedure
    .input(z.object({ id: z.string() }))
    .query(async ({ input }) => {
      return db.user.findUnique({ where: { id: input.id } });
    }),
});

export type AppRouter = typeof appRouter;

// Client — server type is inferred automatically, no codegen
import { createTRPCClient, httpBatchLink } from '@trpc/client';
import type { AppRouter } from './server';

const client = createTRPCClient<AppRouter>({
  links: [httpBatchLink({ url: 'http://localhost:3000/trpc' })],
});

const user = await client.getUser.query({ id: '1' });
// user: { id: string; name: string; ... } — full type safety at compile time

// graphql-js + @apollo/server — schema, resolver, and server in one file
import { ApolloServer } from '@apollo/server';
import { startStandaloneServer } from '@apollo/server/standalone';
// db = your Prisma/ORM client (imported from a separate file)

const typeDefs = `#graphql
  type Post {
    id: ID!
    title: String!
  }

  type User {
    id: ID!
    name: String!
    posts: [Post!]!
  }

  type Query {
    user(id: ID!): User
  }
`;

const resolvers = {
  Query: {
    user: (_parent, { id }, { db }) => db.user.findUnique({ where: { id } }),
  },
  User: {
    posts: (user, _args, { db }) =>
      db.post.findMany({ where: { authorId: user.id } }),
  },
};

const server = new ApolloServer({ typeDefs, resolvers });

const { url } = await startStandaloneServer(server, {
  context: async () => ({ db }),
  listen: { port: 4000 },
});
console.log(`Server ready: ${url}`);

// Client query — only the needed fields are selected:
// query { user(id: "1") { name posts { title } } }