auth()

The auth() helper returns the Auth object of the currently active user, as well as the redirectToSignIn() method.

• Only available for App Router.
• Only works on the server-side, such as in Server Components, Route Handlers, and Server Actions.
• Requires clerkMiddleware() to be configured.

auth.protect()

auth includes a single property, the protect() method, which you can use in two ways:

• to check if a user is authenticated (signed in)
• to check if a user is authorized (has the correct roles or permissions) to access something, such as a component or a route handler

The following table describes how auth.protect() behaves based on user authentication or authorization status:

auth.protect() accepts the following parameters:

Examples

auth.protect() can be used to check if a user is authenticated or authorized to access certain parts of your application or even entire routes. See detailed examples in the dedicated guide.

redirectToSignIn()

The auth() helper returns the redirectToSignIn() method, which you can use to redirect the user to the sign-in page.

redirectToSignIn() accepts the following parameters:

Example

The following example shows how to use redirectToSignIn() to redirect the user to the sign-in page if they are not authenticated. It's also common to use redirectToSignIn() in clerkMiddleware() to protect entire routes; see the clerkMiddleware() docs for more information.

import { auth } from '@clerk/nextjs/server'

export default async function Page() {
  const { userId, redirectToSignIn } = await auth()

  if (!userId) return redirectToSignIn()

  return <h1>Hello, {userId}</h1>
}

Use auth() to retrieve userId

You can use auth() to check if a userId exists. If it does not, that means there is no user signed in. You can use this information to protect pages, as shown in the following example:

import { auth } from '@clerk/nextjs/server'

export default async function Page() {
  const { userId }: { userId: string | null } = await auth()

  if (!userId) return null

  return <h1>Hello, {userId}</h1>
}

Use auth() for data fetching

When using a Clerk integration, or if you need to send a JWT along to a server, you can use the getToken() function that is returned by auth().

import { auth } from '@clerk/nextjs/server'

export async function GET() {
  const { userId, getToken } = await auth()

  if (!userId) {
    return new Response('User is not signed in.', { status: 401 })
  }

  try {
    const token = await getToken({ template: 'supabase' })

    // Add logic here to fetch data from Supabase and return it.

    const data = { supabaseData: 'Hello World' }

    return Response.json({ data })
  } catch (error) {
    return Response.json(error)
  }
}

Use auth() to protect your app

You can protect certain parts of your application or even entire routes based on a user's authentication and/or authorization status. See detailed examples in the dedicated guide.