Define Router

info

• A procedure can be viewed as the equivalent of a REST-endpoint.
• There's no internal difference between queries and mutations apart from semantics.
• Defining router is the same for queries, mutations, and subscription with the exception that subscriptions need to return an observable instance.

Input validation

tRPC works out-of-the-box with yup/superstruct/zod/myzod/custom validators/[..] - see test suite

Example without input

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

export const t = initTRPC()();

export const appRouter = t.router({
  // Create procedure at path 'hello'
  hello: t.query(() => {
    return {
      greeting: 'hello world',
    };
  }),
});

With Zod

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

export const t = initTRPC()();

export const appRouter = t.router({
  hello: t.procedure
    .input(
      z
        .object({
          text: z.string().nullish(),
        })
        .nullish(),
    )
    .query(({ input }) => {
      return {
        greeting: `hello ${input?.text ?? 'world'}`,
      };
    }),
});

export type AppRouter = typeof appRouter;

With Yup

import { initTRPC } from '@trpc/server';
import * as yup from 'yup';

export const t = initTRPC()();

export const appRouter = t.router({
  hello: t.procedure
    .input(
      yup.object({
        text: yup.string().required(),
      }),
    )
    .query(({ input }) => {
      return {
        greeting: `hello ${input?.text ?? 'world'}`,
      };
    }),
});

export type AppRouter = typeof appRouter;

With Superstruct

import { initTRPC } from '@trpc/server';
import { defaulted, object, string } from 'superstruct';

export const t = initTRPC()();

export const appRouter = t.router({
  hello: t.procedure
    .input(
      object({
        /**
         * Also supports inline doc strings when referencing the type.
         */
        text: defaulted(string(), 'world'),
      }),
    )
    .query(({ input }) => {
      return {
        greeting: `hello ${input.text}`,
      };
    }),
});

export type AppRouter = typeof appRouter;

Multiple Procedures

To add multiple procedures, you can define them as properties on the object passed to t.router().

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

export const t = initTRPC()();

export const appRouter = t.router({
  hello: t.procedure.query(() => {
    return {
      text: 'hello world',
    };
  }),
  bye: t.procedure.query(() => {
    return {
      text: 'goodbye',
    };
  }),
});

export type AppRouter = typeof appRouter;