Usage with the Fetch API

tRPC includes an adapter for the native Fetch API out of the box. This adapter lets you convert your tRPC router into a Request handler that returns Response objects.

Example apps

Description	Links
Cloudflare Workers example	Source
Deno Deploy example	Source
Next.js Edge Runtime example	Source
Vercel Edge Runtime example	Source

Common setup

Install dependencies

tip

You can skip this step if you use Deno Deploy.

npm

sh
npm install @trpc/server zod

sh
npm install @trpc/server zod

yarn

sh
yarn add @trpc/server zod

sh
yarn add @trpc/server zod

pnpm

sh
pnpm add @trpc/server zod

sh
pnpm add @trpc/server zod

Zod isn't a required dependency, but it's used in the sample router below.

Create the router

First of all you need a router to handle your queries, mutations and subscriptions.

A sample router is given below, save it in a file named router.ts.

router.ts

router.ts
ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
import { Context } from './context';
type User = {
  id: string;
  name: string;
  bio?: string;
};
const users: Record<string, User> = {};
export const t = initTRPC.context<Context>().create();
export const appRouter = t.router({
  getUserById: t.procedure.input(z.string()).query(({ input }) => {
    return users[input]; // input type is string
  }),
  createUser: t.procedure
    // validate input with Zod
    .input(
      z.object({
        name: z.string().min(3),
        bio: z.string().max(142).optional(),
      }),
    )
    .mutation(({ input }) => {
      const id = Date.now().toString();
      const user: User = { id, ...input };
      users[user.id] = user;
      return user;
    }),
});
// export type definition of API
export type AppRouter = typeof appRouter;

router.ts
ts
import { initTRPC } from '@trpc/server';
import { z } from 'zod';
import { Context } from './context';
type User = {
  id: string;
  name: string;
  bio?: string;
};
const users: Record<string, User> = {};
export const t = initTRPC.context<Context>().create();
export const appRouter = t.router({
  getUserById: t.procedure.input(z.string()).query(({ input }) => {
    return users[input]; // input type is string
  }),
  createUser: t.procedure
    // validate input with Zod
    .input(
      z.object({
        name: z.string().min(3),
        bio: z.string().max(142).optional(),
      }),
    )
    .mutation(({ input }) => {
      const id = Date.now().toString();
      const user: User = { id, ...input };
      users[user.id] = user;
      return user;
    }),
});
// export type definition of API
export type AppRouter = typeof appRouter;

If your router file starts getting too big, split your router into several subrouters each implemented in its own file. Then merge them into a single root appRouter.

Create the context

Then you need a context that will be created for each request.

A sample context is given below, save it in a file named context.ts:

context.ts

context.ts
ts
import { inferAsyncReturnType } from '@trpc/server';
import { FetchCreateContextFnOptions } from '@trpc/server/adapters/fetch';
export function createContext({ req }: FetchCreateContextFnOptions) {
  const user = { name: req.headers.get('username') ?? 'anonymous' };
  return { req, user };
}
export type Context = inferAsyncReturnType<typeof createContext>;

context.ts
ts
import { inferAsyncReturnType } from '@trpc/server';
import { FetchCreateContextFnOptions } from '@trpc/server/adapters/fetch';
export function createContext({ req }: FetchCreateContextFnOptions) {
  const user = { name: req.headers.get('username') ?? 'anonymous' };
  return { req, user };
}
export type Context = inferAsyncReturnType<typeof createContext>;

Runtimes-specific setup

Cloudflare Worker

Install dependencies

npm

sh
npm install -g wrangler

sh
npm install -g wrangler

yarn

sh
yarn global add wrangler

sh
yarn global add wrangler

pnpm

sh
pnpm add -g wrangler

sh
pnpm add -g wrangler

Create Cloudflare Worker

server.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from './context';
import { appRouter } from './router';
export default {
  async fetch(request: Request): Promise<Response> {
    return fetchRequestHandler({
      endpoint: '/trpc',
      req: request,
      router: appRouter,
      createContext,
    });
  },
};

server.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from './context';
import { appRouter } from './router';
export default {
  async fetch(request: Request): Promise<Response> {
    return fetchRequestHandler({
      endpoint: '/trpc',
      req: request,
      router: appRouter,
      createContext,
    });
  },
};

Run wrangler dev server.ts and your endpoints will be available via HTTP!

Endpoint	HTTP URI
getUser	GET http://localhost:8787/trpc/getUserById?input=INPUT where INPUT is a URI-encoded JSON string.
createUser	POST http://localhost:8787/trpc/createUser with req.body of type User

Deno Deploy

Install dependencies

macOS / Linux

sh
curl -fsSL https://deno.land/x/install/install.sh | sh

sh
curl -fsSL https://deno.land/x/install/install.sh | sh

Windows

sh
irm https://deno.land/install.ps1 | iex

sh
irm https://deno.land/install.ps1 | iex

Update the imports in router.ts

router.ts
ts
import { initTRPC } from 'npm:@trpc/server';
import { z } from 'npm:zod';
import { Context } from './context.ts';

router.ts
ts
import { initTRPC } from 'npm:@trpc/server';
import { z } from 'npm:zod';
import { Context } from './context.ts';

Update the imports in context.ts

context.ts
ts
import { inferAsyncReturnType } from 'npm:@trpc/server';
import { FetchCreateContextFnOptions } from 'npm:@trpc/server/adapters/fetch';

context.ts
ts
import { inferAsyncReturnType } from 'npm:@trpc/server';
import { FetchCreateContextFnOptions } from 'npm:@trpc/server/adapters/fetch';

Create Deno Deploy Function

server.ts
ts
import { serve } from 'https://deno.land/std@0.140.0/http/server.ts';
import { fetchRequestHandler } from 'npm:@trpc/server/adapters/fetch';
import { createContext } from './context.ts';
import { appRouter } from './router.ts';
function handler(request) {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: request,
    router: appRouter,
    createContext,
  });
}
serve(handler);

server.ts
ts
import { serve } from 'https://deno.land/std@0.140.0/http/server.ts';
import { fetchRequestHandler } from 'npm:@trpc/server/adapters/fetch';
import { createContext } from './context.ts';
import { appRouter } from './router.ts';
function handler(request) {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: request,
    router: appRouter,
    createContext,
  });
}
serve(handler);

Run deno run --allow-net=:8000 --allow-env ./server.ts and your endpoints will be available via HTTP!

Endpoint	HTTP URI
getUser	GET http://localhost:8000/trpc/getUserById?input=INPUT where INPUT is a URI-encoded JSON string.
createUser	POST http://localhost:8000/trpc/createUser with req.body of type User

Next.js Edge Runtime

See a full example here.

Vercel Edge Runtime

Install dependencies

npm

sh
npm install -g edge-runtime

sh
npm install -g edge-runtime

yarn

sh
yarn global add edge-runtime

sh
yarn global add edge-runtime

pnpm

sh
pnpm add -g edge-runtime

sh
pnpm add -g edge-runtime

Create Edge Runtime Function

server.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from './context';
import { appRouter } from './router';
addEventListener('fetch', (event) => {
  return event.respondWith(
    fetchRequestHandler({
      endpoint: '/trpc',
      req: event.request,
      router: appRouter,
      createContext,
    }),
  );
});

server.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from './context';
import { appRouter } from './router';
addEventListener('fetch', (event) => {
  return event.respondWith(
    fetchRequestHandler({
      endpoint: '/trpc',
      req: event.request,
      router: appRouter,
      createContext,
    }),
  );
});

Run edge-runtime --listen server.ts and your endpoints will be available via HTTP!

Endpoint	HTTP URI
getUser	GET http://localhost:3000/trpc/getUserById?input=INPUT where INPUT is a URI-encoded JSON string.
createUser	POST http://localhost:3000/trpc/createUser with req.body of type User