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Version: 11.x

Set up with React Server Components

This guide is an overview of how one may use tRPC with a React Server Components (RSC) framework such as Next.js App Router. Be aware that RSC on its own solves a lot of the same problems tRPC was designed to solve, so you may not need tRPC at all.

There are also not a one-size-fits-all way to integrate tRPC with RSCs, so see this guide as a starting point and adjust it to your needs and preferences.

info

If you're looking for how to use tRPC with Server Actions, check out this blog post by Julius.

caution

Please read React Query's Advanced Server Rendering docs before proceeding to understand the different types of server rendering and what footguns to avoid.

Add tRPC to existing projects​

1. Install deps​

npm install @trpc/server@next @trpc/client@next @trpc/tanstack-react-query@next @tanstack/react-query@latest zod client-only server-only

2. Create a tRPC router​

Initialize your tRPC backend in trpc/init.ts using the initTRPC function, and create your first router. We're going to make a simple "hello world" router and procedure here - but for deeper information on creating your tRPC API you should refer to the Quickstart guide and Backend usage docs for tRPC information.

info

The file names used here are not enforced by tRPC. You may use any file structure you wish.

View sample backend
trpc/init.ts
ts
import { initTRPC } from '@trpc/server';
import { cache } from 'react';
export const createTRPCContext = cache(async () => {
  /**
   * @see: https://trpc.io/docs/server/context
   */
  return { userId: 'user_123' };
});
// Avoid exporting the entire t-object
// since it's not very descriptive.
// For instance, the use of a t variable
// is common in i18n libraries.
const t = initTRPC.create({
  /**
   * @see https://trpc.io/docs/server/data-transformers
   */
  // transformer: superjson,
});
// Base router and procedure helpers
export const createTRPCRouter = t.router;
export const createCallerFactory = t.createCallerFactory;
export const baseProcedure = t.procedure;
trpc/init.ts
ts
import { initTRPC } from '@trpc/server';
import { cache } from 'react';
export const createTRPCContext = cache(async () => {
  /**
   * @see: https://trpc.io/docs/server/context
   */
  return { userId: 'user_123' };
});
// Avoid exporting the entire t-object
// since it's not very descriptive.
// For instance, the use of a t variable
// is common in i18n libraries.
const t = initTRPC.create({
  /**
   * @see https://trpc.io/docs/server/data-transformers
   */
  // transformer: superjson,
});
// Base router and procedure helpers
export const createTRPCRouter = t.router;
export const createCallerFactory = t.createCallerFactory;
export const baseProcedure = t.procedure;

trpc/routers/_app.ts
ts
import { z } from 'zod';
import { baseProcedure, createTRPCRouter } from '../init';
export const appRouter = createTRPCRouter({
  hello: baseProcedure
    .input(
      z.object({
        text: z.string(),
      }),
    )
    .query((opts) => {
      return {
        greeting: `hello ${opts.input.text}`,
      };
    }),
});
// export type definition of API
export type AppRouter = typeof appRouter;
trpc/routers/_app.ts
ts
import { z } from 'zod';
import { baseProcedure, createTRPCRouter } from '../init';
export const appRouter = createTRPCRouter({
  hello: baseProcedure
    .input(
      z.object({
        text: z.string(),
      }),
    )
    .query((opts) => {
      return {
        greeting: `hello ${opts.input.text}`,
      };
    }),
});
// export type definition of API
export type AppRouter = typeof appRouter;

note

The backend adapter depends on your framework and how it sets up API routes. The following example sets up GET and POST routes at /api/trpc/* using the fetch adapter in Next.js.

app/api/trpc/[trpc]/route.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createTRPCContext } from '~/trpc/init';
import { appRouter } from '~/trpc/routers/_app';
const handler = (req: Request) =>
  fetchRequestHandler({
    endpoint: '/api/trpc',
    req,
    router: appRouter,
    createContext: createTRPCContext,
  });
export { handler as GET, handler as POST };
app/api/trpc/[trpc]/route.ts
ts
import { fetchRequestHandler } from '@trpc/server/adapters/fetch';
import { createTRPCContext } from '~/trpc/init';
import { appRouter } from '~/trpc/routers/_app';
const handler = (req: Request) =>
  fetchRequestHandler({
    endpoint: '/api/trpc',
    req,
    router: appRouter,
    createContext: createTRPCContext,
  });
export { handler as GET, handler as POST };

3. Create a Query Client factory​

Create a shared file trpc/query-client.ts that exports a function that creates a QueryClient instance.

trpc/query-client.ts
ts
import {
  defaultShouldDehydrateQuery,
  QueryClient,
} from '@tanstack/react-query';
import superjson from 'superjson';
export function makeQueryClient() {
  return new QueryClient({
    defaultOptions: {
      queries: {
        staleTime: 30 * 1000,
      },
      dehydrate: {
        // serializeData: superjson.serialize,
        shouldDehydrateQuery: (query) =>
          defaultShouldDehydrateQuery(query) ||
          query.state.status === 'pending',
      },
      hydrate: {
        // deserializeData: superjson.deserialize,
      },
    },
  });
}
trpc/query-client.ts
ts
import {
  defaultShouldDehydrateQuery,
  QueryClient,
} from '@tanstack/react-query';
import superjson from 'superjson';
export function makeQueryClient() {
  return new QueryClient({
    defaultOptions: {
      queries: {
        staleTime: 30 * 1000,
      },
      dehydrate: {
        // serializeData: superjson.serialize,
        shouldDehydrateQuery: (query) =>
          defaultShouldDehydrateQuery(query) ||
          query.state.status === 'pending',
      },
      hydrate: {
        // deserializeData: superjson.deserialize,
      },
    },
  });
}

We're setting a few default options here:

  • staleTime: With SSR, we usually want to set some default staleTime above 0 to avoid refetching immediately on the client.
  • shouldDehydrateQuery: This is a function that determines whether a query should be dehydrated or not. Since the RSC transport protocol supports hydrating promises over the network, we extend the defaultShouldDehydrateQuery function to also include queries that are still pending. This will allow us to start prefetching in a server component high up the tree, then consuming that promise in a client component further down.
  • serializeData and deserializeData (optional): If you set up a data transformer in the previous step, set this option to make sure the data is serialized correctly when hydrating the query client over the server-client boundary.

4. Create a tRPC client for Client Components​

The trpc/client.tsx is the entrypoint when consuming your tRPC API from client components. In here, import the type definition of your tRPC router and create typesafe hooks using createTRPCContext. We'll also export our context provider from this file.

trpc/client.tsx
tsx
'use client';
// ^-- to make sure we can mount the Provider from a server component
import type { QueryClient } from '@tanstack/react-query';
import { QueryClientProvider } from '@tanstack/react-query';
import { createTRPCClient, httpBatchLink } from '@trpc/client';
import { useState } from 'react';
import { makeQueryClient } from './query-client';
import type { AppRouter } from './routers/_app';
export const { TRPCProvider, useTRPC } = createTRPCContext<AppRouter>();
let browserQueryClient: QueryClient;
function getQueryClient() {
  if (typeof window === 'undefined') {
    // Server: always make a new query client
    return makeQueryClient();
  }
  // Browser: make a new query client if we don't already have one
  // This is very important, so we don't re-make a new client if React
  // suspends during the initial render. This may not be needed if we
  // have a suspense boundary BELOW the creation of the query client
  if (!browserQueryClient) browserQueryClient = makeQueryClient();
  return browserQueryClient;
}
function getUrl() {
  const base = (() => {
    if (typeof window !== 'undefined') return '';
    if (process.env.VERCEL_URL) return `https://${process.env.VERCEL_URL}`;
    return 'http://localhost:3000';
  })();
  return `${base}/api/trpc`;
}
export function TRPCReactProvider(
  props: Readonly<{
    children: React.ReactNode;
  }>,
) {
  // NOTE: Avoid useState when initializing the query client if you don't
  //       have a suspense boundary between this and the code that may
  //       suspend because React will throw away the client on the initial
  //       render if it suspends and there is no boundary
  const queryClient = getQueryClient();
  const [trpcClient] = useState(() =>
    createTRPCClient<AppRouter>({
      links: [
        httpBatchLink({
          // transformer: superjson, <-- if you use a data transformer
          url: getUrl(),
        }),
      ],
    }),
  );
  return (
    <QueryClientProvider client={queryClient}>
      <TRPCProvider trpcClient={trpcClient} queryClient={queryClient}>
        {props.children}
      </TRPCProvider>
    </QueryClientProvider>
  );
}
trpc/client.tsx
tsx
'use client';
// ^-- to make sure we can mount the Provider from a server component
import type { QueryClient } from '@tanstack/react-query';
import { QueryClientProvider } from '@tanstack/react-query';
import { createTRPCClient, httpBatchLink } from '@trpc/client';
import { useState } from 'react';
import { makeQueryClient } from './query-client';
import type { AppRouter } from './routers/_app';
export const { TRPCProvider, useTRPC } = createTRPCContext<AppRouter>();
let browserQueryClient: QueryClient;
function getQueryClient() {
  if (typeof window === 'undefined') {
    // Server: always make a new query client
    return makeQueryClient();
  }
  // Browser: make a new query client if we don't already have one
  // This is very important, so we don't re-make a new client if React
  // suspends during the initial render. This may not be needed if we
  // have a suspense boundary BELOW the creation of the query client
  if (!browserQueryClient) browserQueryClient = makeQueryClient();
  return browserQueryClient;
}
function getUrl() {
  const base = (() => {
    if (typeof window !== 'undefined') return '';
    if (process.env.VERCEL_URL) return `https://${process.env.VERCEL_URL}`;
    return 'http://localhost:3000';
  })();
  return `${base}/api/trpc`;
}
export function TRPCReactProvider(
  props: Readonly<{
    children: React.ReactNode;
  }>,
) {
  // NOTE: Avoid useState when initializing the query client if you don't
  //       have a suspense boundary between this and the code that may
  //       suspend because React will throw away the client on the initial
  //       render if it suspends and there is no boundary
  const queryClient = getQueryClient();
  const [trpcClient] = useState(() =>
    createTRPCClient<AppRouter>({
      links: [
        httpBatchLink({
          // transformer: superjson, <-- if you use a data transformer
          url: getUrl(),
        }),
      ],
    }),
  );
  return (
    <QueryClientProvider client={queryClient}>
      <TRPCProvider trpcClient={trpcClient} queryClient={queryClient}>
        {props.children}
      </TRPCProvider>
    </QueryClientProvider>
  );
}

Mount the provider in the root of your application (e.g. app/layout.tsx when using Next.js).

5. Create a tRPC caller for Server Components​

To prefetch queries from server components, we create a proxy from our router. You can also pass in a client if your router is on a separate server.

trpc/server.tsx
tsx
import 'server-only'; // <-- ensure this file cannot be imported from the client
import { createTRPCOptionsProxy } from '@trpc/tanstack-react-query';
import { cache } from 'react';
import { createTRPCContext } from './init';
import { makeQueryClient } from './query-client';
import { appRouter } from './routers/_app';
// IMPORTANT: Create a stable getter for the query client that
//            will return the same client during the same request.
export const getQueryClient = cache(makeQueryClient);
export const trpc = createTRPCOptionsProxy({
  ctx: createTRPCContext,
  router: appRouter,
  queryClient: getQueryClient,
});
// If your router is on a separate server, pass a client:
createTRPCOptionsProxy({
  client: createTRPCClient({
    links: [httpLink({ url: '...' })],
  }),
  queryClient: getQueryClient,
});
trpc/server.tsx
tsx
import 'server-only'; // <-- ensure this file cannot be imported from the client
import { createTRPCOptionsProxy } from '@trpc/tanstack-react-query';
import { cache } from 'react';
import { createTRPCContext } from './init';
import { makeQueryClient } from './query-client';
import { appRouter } from './routers/_app';
// IMPORTANT: Create a stable getter for the query client that
//            will return the same client during the same request.
export const getQueryClient = cache(makeQueryClient);
export const trpc = createTRPCOptionsProxy({
  ctx: createTRPCContext,
  router: appRouter,
  queryClient: getQueryClient,
});
// If your router is on a separate server, pass a client:
createTRPCOptionsProxy({
  client: createTRPCClient({
    links: [httpLink({ url: '...' })],
  }),
  queryClient: getQueryClient,
});

Using your API​

Now you can use your tRPC API in your app. While you can use the React Query hooks in client components just like you would in any other React app, we can take advantage of the RSC capabilities by prefetching queries in a server component high up the tree. You may be familiar with this concept as "render as you fetch" commonly implemented as loaders. This means the request fires as soon as possible but without suspending until the data is needed by using the useQuery or useSuspenseQuery hooks.

app/page.tsx
tsx
import { dehydrate, HydrationBoundary } from '@tanstack/react-query';
import { getQueryClient, trpc } from '~/trpc/server';
import { ClientGreeting } from './client-greeting';
export default async function Home() {
  const queryClient = getQueryClient();
  void queryClient.prefetchQuery(
    trpc.hello.queryOptions({
      /** input */
    }),
  );
  return (
    <HydrationBoundary state={dehydrate(queryClient)}>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrationBoundary>
  );
}
app/page.tsx
tsx
import { dehydrate, HydrationBoundary } from '@tanstack/react-query';
import { getQueryClient, trpc } from '~/trpc/server';
import { ClientGreeting } from './client-greeting';
export default async function Home() {
  const queryClient = getQueryClient();
  void queryClient.prefetchQuery(
    trpc.hello.queryOptions({
      /** input */
    }),
  );
  return (
    <HydrationBoundary state={dehydrate(queryClient)}>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrationBoundary>
  );
}
app/client-greeting.tsx
tsx
'use client';
// <-- hooks can only be used in client components
import { trpc } from '~/trpc/client';
export function ClientGreeting() {
  const greeting = trpc.hello.useQuery();
  if (!greeting.data) return <div>Loading...</div>;
  return <div>{greeting.data.greeting}</div>;
}
app/client-greeting.tsx
tsx
'use client';
// <-- hooks can only be used in client components
import { trpc } from '~/trpc/client';
export function ClientGreeting() {
  const greeting = trpc.hello.useQuery();
  if (!greeting.data) return <div>Loading...</div>;
  return <div>{greeting.data.greeting}</div>;
}
tip

You can also create a prefetch and HydrateClient helper functions to make it a bit more consice and reusable:

trpc/server.tsx
tsx
export function HydrateClient(props: { children: React.ReactNode }) {
  const queryClient = getQueryClient();
  return (
    <HydrationBoundary state={dehydrate(queryClient)}>
      {props.children}
    </HydrationBoundary>
  );
}
export function prefetch<T extends ReturnType<TRPCQueryOptions<any>>>(
  queryOptions: T,
) {
  const queryClient = getQueryClient();
  if (queryOptions.queryKey[1]?.type === 'infinite') {
    void queryClient.prefetchInfiniteQuery(queryOptions as any);
  } else {
    void queryClient.prefetchQuery(queryOptions);
  }
}
trpc/server.tsx
tsx
export function HydrateClient(props: { children: React.ReactNode }) {
  const queryClient = getQueryClient();
  return (
    <HydrationBoundary state={dehydrate(queryClient)}>
      {props.children}
    </HydrationBoundary>
  );
}
export function prefetch<T extends ReturnType<TRPCQueryOptions<any>>>(
  queryOptions: T,
) {
  const queryClient = getQueryClient();
  if (queryOptions.queryKey[1]?.type === 'infinite') {
    void queryClient.prefetchInfiniteQuery(queryOptions as any);
  } else {
    void queryClient.prefetchQuery(queryOptions);
  }
}

Then you can use it like this:

tsx
import { HydrateClient, prefetch, trpc } from '~/trpc/server';
function Home() {
  prefetch(
    trpc.hello.queryOptions({
      /** input */
    }),
  );
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrateClient>
  );
}
tsx
import { HydrateClient, prefetch, trpc } from '~/trpc/server';
function Home() {
  prefetch(
    trpc.hello.queryOptions({
      /** input */
    }),
  );
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrateClient>
  );
}

Leveraging Suspense​

You may prefer handling loading and error states using Suspense and Error Boundaries. You can do this by using the useSuspenseQuery hook.

app/page.tsx
tsx
import { HydrateClient, prefetch, trpc } from '~/trpc/server';
import { Suspense } from 'react';
import { ErrorBoundary } from 'react-error-boundary';
import { ClientGreeting } from './client-greeting';
export default async function Home() {
  prefetch(trpc.hello.queryOptions());
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ErrorBoundary fallback={<div>Something went wrong</div>}>
        <Suspense fallback={<div>Loading...</div>}>
          <ClientGreeting />
        </Suspense>
      </ErrorBoundary>
    </HydrateClient>
  );
}
app/page.tsx
tsx
import { HydrateClient, prefetch, trpc } from '~/trpc/server';
import { Suspense } from 'react';
import { ErrorBoundary } from 'react-error-boundary';
import { ClientGreeting } from './client-greeting';
export default async function Home() {
  prefetch(trpc.hello.queryOptions());
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ErrorBoundary fallback={<div>Something went wrong</div>}>
        <Suspense fallback={<div>Loading...</div>}>
          <ClientGreeting />
        </Suspense>
      </ErrorBoundary>
    </HydrateClient>
  );
}
app/client-greeting.tsx
tsx
'use client';
import { useSuspenseQuery } from '@tanstack/react-query';
import { trpc } from '~/trpc/client';
export function ClientGreeting() {
  const trpc = useTRPC();
  const [data] = useSuspenseQuery(trpc.hello.queryOptions());
  return <div>{data.greeting}</div>;
}
app/client-greeting.tsx
tsx
'use client';
import { useSuspenseQuery } from '@tanstack/react-query';
import { trpc } from '~/trpc/client';
export function ClientGreeting() {
  const trpc = useTRPC();
  const [data] = useSuspenseQuery(trpc.hello.queryOptions());
  return <div>{data.greeting}</div>;
}

Getting data in a server component​

If you need access to the data in a server component, we recommend creating a server caller and using it directly. Please note that this method is detached from your query client and does not store the data in the cache. This means that you cannot use the data in a server component and expect it to be available in the client. This is intentional and explained in more detail in the Advanced Server Rendering guide.

trpc/server.tsx
tsx
// ...
export const caller = appRouter.createCaller(createTRPCContext);
trpc/server.tsx
tsx
// ...
export const caller = appRouter.createCaller(createTRPCContext);
app/page.tsx
tsx
import { caller } from '~/trpc/server';
export default async function Home() {
  const greeting = await caller.hello();
  //    ^? { greeting: string }
  return <div>{greeting.greeting}</div>;
}
app/page.tsx
tsx
import { caller } from '~/trpc/server';
export default async function Home() {
  const greeting = await caller.hello();
  //    ^? { greeting: string }
  return <div>{greeting.greeting}</div>;
}

If you really need to use the data both on the server as well as inside client components and understand the tradeoffs explained in the Advanced Server Rendering guide, you can use fetchQuery instead of prefetch to have the data both on the server as well as hydrating it down to the client:

app/page.tsx
tsx
import { getQueryClient, HydrateClient, trpc } from '~/trpc/server';
export default async function Home() {
  const queryClient = getQueryClient();
  const greeting = await queryClient.fetchQuery(trpc.hello.queryOptions());
  // Do something with greeting on the server
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrateClient>
  );
}
app/page.tsx
tsx
import { getQueryClient, HydrateClient, trpc } from '~/trpc/server';
export default async function Home() {
  const queryClient = getQueryClient();
  const greeting = await queryClient.fetchQuery(trpc.hello.queryOptions());
  // Do something with greeting on the server
  return (
    <HydrateClient>
      <div>...</div>
      {/** ... */}
      <ClientGreeting />
    </HydrateClient>
  );
}