Getting Started

The example code below describes how to add authentication to a Next.js app.

New Project

The easiest way to get started is to clone the example app and follow the instructions in README.md. You can try out a live demo at https://next-auth-example.vercel.app/

Existing Project

Add API route

To add NextAuth.js to a project create a file called [...nextauth].js in pages/api/auth. This contains the dynamic route handler for NextAuth.js which will also contain all of your global NextAuth.js configurations.

pages/api/auth/[...nextauth].js

import NextAuth from "next-auth"
import GithubProvider from "next-auth/providers/github"

export default NextAuth({
  // Configure one or more authentication providers
  providers: [
    GithubProvider({
      clientId: process.env.GITHUB_ID,
      clientSecret: process.env.GITHUB_SECRET,
    }),
    // ...add more providers here
  ],
})

All requests to /api/auth/* (signIn, callback, signOut, etc.) will automatically be handled by NextAuth.js.

Further Reading:

• See the options documentation for more details on how to configure providers, databases and other options.
• Read more about how to add authentication providers here.

Configure Shared session state

To be able to use useSession first you'll need to expose the session context, <SessionProvider />, at the top level of your application:

// pages/_app.js
import { SessionProvider } from "next-auth/react"

export default function App({
  Component,
  pageProps: { session, ...pageProps },
}) {
  return (
    <SessionProvider session={session}>
      <Component {...pageProps} />
    </SessionProvider>
  )
}

Instances of useSession will then have access to the session data and status. The <SessionProvider /> also takes care of keeping the session updated and synced between browser tabs and windows.

tip

Check out the client documentation to see how you can improve the user experience and page performance by using the NextAuth.js client.

Frontend - Add React Hook

The useSession() React Hook in the NextAuth.js client is the easiest way to check if someone is signed in.

import { useSession, signIn, signOut } from "next-auth/react"

export default function Component() {
  const { data: session } = useSession()
  if (session) {
    return (
      <>
        Signed in as {session.user.email} <br />
        <button onClick={() => signOut()}>Sign out</button>
      </>
    )
  }
  return (
    <>
      Not signed in <br />
      <button onClick={() => signIn()}>Sign in</button>
    </>
  )
}

You can use the useSession hook from anywhere in your application (e.g. in a header component).

Backend - API Route

To protect an API Route, you can use the getSession() method in the NextAuth.js client.

import { getSession } from "next-auth/react"

export default async (req, res) => {
  const session = await getSession({ req })

  if (session) {
    res.send({
      content:
        "This is protected content. You can access this content because you are signed in.",
    })
  } else {
    res.send({
      error: "You must be sign in to view the protected content on this page.",
    })
  }
}

Extensibility

Using NextAuth.js Callbacks

NextAuth.js allows you to hook into various parts of the authentication flow via our built-in callbacks.

For example, to pass a value from the sign-in to the frontend, client-side, you can use a combination of the session and jwt callback like so:

...
callbacks: {
  async jwt({ token, account }) {
    // Persist the OAuth access_token to the token right after signin
    if (account) {
      token.accessToken = account.access_token
    }
    return token
  },
  async session({ session, token, user }) {
    // Send properties to the client, like an access_token from a provider.
    session.accessToken = token.accessToken
    return session
  }
}
...

Now whenever you call getSession or useSession, the data object which is returned will include the accessToken value.

import { useSession, signIn, signOut } from "next-auth/react"

export default function Component() {
  const { data } = useSession()
  const { accessToken } = data

  return <div>Access Token: {accessToken}</div>
}

Deploying to production

When deploying your site set the NEXTAUTH_URL environment variable to the canonical URL of the website.

NEXTAUTH_URL=https://example.com

tip

In production, this needs to be set as an environment variable on the service you use to deploy your app.

To set environment variables on Vercel, you can use the dashboard or the vercel env pull command.