Step1

import { initTRPC } from '@trpc/server';
import z from 'zod';

// ---cut---
const t = initTRPC.create();

const router = t.router;
const publicProcedure = t.procedure;

const appRouter = router({
  greeting: publicProcedure
    .input(z.object({ name: z.string() }))
    .query((opts) => {
      const { input } = opts;
      //      ^?

      return `Hello ${input.name}` as const;
  }),
});

export type AppRouter = typeof appRouter;