info

• If you're using Next.js, read the Usage with Next.js guide instead.
• In order to infer types from your Node.js backend you should have the frontend & backend in the same monorepo.

Add tRPC to existing React project​

Server Side​

1. Install dependencies​

bash

yarn add @trpc/server zod

• Zod: most examples use Zod for input validation and we highly recommended it, though it isn't required. You can use a validation library of your choice (Yup, Superstruct, io-ts, etc). In fact, any object containing a parse, create or validateSync method will work.

2. Enable strict mode​

If you want to use Zod for input validation, make sure you have enabled strict mode in your tsconfig.json:

json

// tsconfig.json

{

// ...

"compilerOptions": {

`// ...`

`"strict": true`

}

}

If strict mode is too much, at least enable strictNullChecks:

json

// tsconfig.json

{

// ...

"compilerOptions": {

`// ...`

`"strictNullChecks": true`

}

}

3. Implement your appRouter​

Follow the Quickstart and read the @trpc/server docs for guidance on this. Once you have your API implemented and listening via HTTP, continue to the next step.

Client Side​

tRPC works fine with Create React App!

1. Install dependencies​

bash

yarn add @trpc/client @trpc/server @trpc/react react-query@3

• @trpc/server: This is a peer dependency of @trpc/client so you have to install it again!
• Tanstack's React Query: @trpc/react provides a thin wrapper over @tanstack/react-query. It is required as a peer dependency.

2. Create tRPC hooks​

Create a set of strongly-typed React hooks from your AppRouter type signature with createReactQueryHooks.

utils/trpc.ts

tsx

// utils/trpc.ts

import { createReactQueryHooks } from '@trpc/react';

import type { AppRouter } from '../path/to/router.ts';

export const trpc = createReactQueryHooks<AppRouter>();

// => { useQuery: ..., useMutation: ...}

3. Add tRPC providers​

In your App.tsx

App.tsx

tsx

import React, { useState } from 'react';

import { QueryClient, QueryClientProvider } from 'react-query';

import { trpc } from './utils/trpc';

export function App() {

const [queryClient] = useState(() => new QueryClient());

const [trpcClient] = useState(() =>

`trpc.createClient({`

  `url: 'http://localhost:5000/trpc',`

  `// optional`

  `headers() {`

    `return {`

      `authorization: getAuthCookie(),`

    `};`

  `},`

`}),`

);

return (

`<trpc.Provider client={trpcClient} queryClient={queryClient}>`

  `<QueryClientProvider client={queryClient}>`

    `{/* Your app here */}`

  `</QueryClientProvider>`

`</trpc.Provider>`

);

}

4. Fetch data​

pages/IndexPage.tsx

tsx

import { trpc } from '../utils/trpc';

export default function IndexPage() {

const hello = trpc.useQuery(['hello', { text: 'client' }]);

if (!hello.data) return <div>Loading...</div>;

return (

`<div>`

  `<p>{hello.data.greeting}</p>`

`</div>`

);

}