Fetch / Edge Runtimes Adapter

You can create a tRPC server within any edge runtime that follow the WinterCG, specifically the Minimum Common Web Platform API specification.

Some of these runtimes includes, but not limited to:

• Cloudflare Workers
• Deno Deploy
• Vercel Edge Runtime (& Next.js Edge Runtime)

This also makes it easy to integrate into frameworks that uses the web platform APIs to represent requests and responses, such as:

• Astro (SSR mode)
• Remix
• SolidStart

Example apps

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

How to use tRPC server with an edge runtime

tRPC provides a fetch adapter that uses the native Request and Response APIs as input and output. The tRPC-specific code is the same across all runtimes, the only difference being how the response is returned.

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.

Required Web APIs

tRPC server uses the following Fetch APIs:

• Request, Response
• fetch
• Headers
• URL

If your runtime supports these APIs, you can use tRPC server.

tip

Fun fact: that also means you can use a tRPC server in your browser!

Common setup

Install dependencies

tip

You can skip this step if you use Deno Deploy.

npm

npm install @trpc/server@next @trpc/client@next zod

yarn

yarn add @trpc/server@next @trpc/client@next zod

pnpm

pnpm add @trpc/server@next @trpc/client@next zod

bun

bun add @trpc/server@next @trpc/client@next 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((opts) => {
    return users[opts.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((opts) => {
      const id = Date.now().toString();
      const user: User = { id, ...opts.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((opts) => {
    return users[opts.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((opts) => {
      const id = Date.now().toString();
      const user: User = { id, ...opts.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 { FetchCreateContextFnOptions } from '@trpc/server/adapters/fetch';
export function createContext({
  req,
  resHeaders,
}: FetchCreateContextFnOptions) {
  const user = { name: req.headers.get('username') ?? 'anonymous' };
  return { req, resHeaders, user };
}
export type Context = Awaited<ReturnType<typeof createContext>>;

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

Runtimes-specific setup

Astro

src/pages/trpc/[trpc].ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import type { APIRoute } from 'astro';
import { createContext } from '../../server/context';
import { appRouter } from '../../server/router';
export const all: APIRoute = (opts) => {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: opts.request,
    router: appRouter,
    createContext,
  });
};

src/pages/trpc/[trpc].ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import type { APIRoute } from 'astro';
import { createContext } from '../../server/context';
import { appRouter } from '../../server/router';
export const all: APIRoute = (opts) => {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: opts.request,
    router: appRouter,
    createContext,
  });
};

Cloudflare Worker

note

You need the Wrangler CLI to run Cloudflare Workers.

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 Oak

note

This assumes you have Deno installed and setup. Refer to their getting started guide for more information.

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 { FetchCreateContextFnOptions } from 'npm:@trpc/server/adapters/fetch';

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

Use fetchRequestHandler with Oak in app.ts

app.ts
ts
import { Application, Router } from 'https://deno.land/x/oak/mod.ts';
import { fetchRequestHandler } from 'npm:@trpc/server/adapters/fetch';
import { createContext } from './context.ts';
import { appRouter } from './router.ts';
const app = new Application();
const router = new Router();
router.all('/trpc/(.*)', async (ctx) => {
  const res = await fetchRequestHandler({
    endpoint: '/trpc',
    req: new Request(ctx.request.url, {
      headers: ctx.request.headers,
      body:
        ctx.request.method !== 'GET' && ctx.request.method !== 'HEAD'
          ? ctx.request.body({ type: 'stream' }).value
          : void 0,
      method: ctx.request.method,
    }),
    router: appRouter,
    createContext,
  });
  ctx.response.status = res.status;
  ctx.response.headers = res.headers;
  ctx.response.body = res.body;
});
app.use(router.routes());
app.use(router.allowedMethods());
await app.listen({ port: 3000 });

app.ts
ts
import { Application, Router } from 'https://deno.land/x/oak/mod.ts';
import { fetchRequestHandler } from 'npm:@trpc/server/adapters/fetch';
import { createContext } from './context.ts';
import { appRouter } from './router.ts';
const app = new Application();
const router = new Router();
router.all('/trpc/(.*)', async (ctx) => {
  const res = await fetchRequestHandler({
    endpoint: '/trpc',
    req: new Request(ctx.request.url, {
      headers: ctx.request.headers,
      body:
        ctx.request.method !== 'GET' && ctx.request.method !== 'HEAD'
          ? ctx.request.body({ type: 'stream' }).value
          : void 0,
      method: ctx.request.method,
    }),
    router: appRouter,
    createContext,
  });
  ctx.response.status = res.status;
  ctx.response.headers = res.headers;
  ctx.response.body = res.body;
});
app.use(router.routes());
app.use(router.allowedMethods());
await app.listen({ port: 3000 });

Deno Deploy

note

This assumes you have Deno installed and setup. Refer to their getting started guide for more information.

tip

See our example Deno Deploy app for a working example.

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 { FetchCreateContextFnOptions } from 'npm:@trpc/server/adapters/fetch';

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

Create Deno Deploy Function

server.ts
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,
  });
}
Deno.serve(handler);

server.ts
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,
  });
}
Deno.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.

Remix

app/routes/trpc/$trpc.ts
ts
import type { ActionArgs, LoaderArgs } from '@remix-run/node';
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from '~/server/context';
import { appRouter } from '~/server/router';
export const loader = async (args: LoaderArgs) => {
  return handleRequest(args);
};
export const action = async (args: ActionArgs) => {
  return handleRequest(args);
};
function handleRequest(args: LoaderArgs | ActionArgs) {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: args.request,
    router: appRouter,
    createContext,
  });
}

app/routes/trpc/$trpc.ts
ts
import type { ActionArgs, LoaderArgs } from '@remix-run/node';
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createContext } from '~/server/context';
import { appRouter } from '~/server/router';
export const loader = async (args: LoaderArgs) => {
  return handleRequest(args);
};
export const action = async (args: ActionArgs) => {
  return handleRequest(args);
};
function handleRequest(args: LoaderArgs | ActionArgs) {
  return fetchRequestHandler({
    endpoint: '/trpc',
    req: args.request,
    router: appRouter,
    createContext,
  });
}

SolidStart

src/routes/api/trpc/[trpc].ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import type { APIEvent } from 'solid-start';
import { createContext } from '../../server/context';
import { appRouter } from '../../server/router';
const handler = (event: APIEvent) =>
  fetchRequestHandler({
    endpoint: '/api/trpc',
    req: event.request,
    router: appRouter,
    createContext,
  });
export { handler as GET, handler as POST };

src/routes/api/trpc/[trpc].ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import type { APIEvent } from 'solid-start';
import { createContext } from '../../server/context';
import { appRouter } from '../../server/router';
const handler = (event: APIEvent) =>
  fetchRequestHandler({
    endpoint: '/api/trpc',
    req: event.request,
    router: appRouter,
    createContext,
  });
export { handler as GET, handler as POST };

Vercel Edge Runtime

note

See the official Vercel Edge Runtime documentation for more information.

tip

See our example Vercel Edge Runtime app for a working example.

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

bun

sh
bun add -g edge-runtime

sh
bun 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 --port 3000 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