The createContext() function is called for each request and the result is propagated to all resolvers. You can use this to pass contextual data down to the resolvers.

server/context.ts

ts

import * as trpc from '@trpc/server';

import * as trpcNext from '@trpc/server/adapters/next';

// The app's context - is generated for each incoming request

export async function createContext(opts?: trpcNext.CreateNextContextOptions) {

// Create your context based on the request object

// Will be available as `ctx` in all your resolvers

// This is just an example of something you'd might want to do in your ctx fn

async function getUserFromHeader() {

`if (opts?.req.headers.authorization) {`

  `// const user = await decodeJwtToken(req.headers.authorization.split(' ')[1])`

  `// return user;`

`}`

`return null;`

}

const user = await getUserFromHeader();

return {

`user,`

};

}

type Context = trpc.inferAsyncReturnType<typeof createContext>;

// Helper function to create a router with your app's context

export function createRouter() {

return trpc.router<Context>();

}