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Version: v4

Next.js

getServerSession

tip

You can create a helper function so you don't need to pass authOptions around:

auth.ts
import type { GetServerSidePropsContext, NextApiRequest, NextApiResponse } from "next"
import type { NextAuthOptions } from "next-auth"
import { getServerSession } from "next-auth"

// You'll need to import and pass this
// to `NextAuth` in `app/api/auth/[...nextauth]/route.ts`
export const config = {
providers: [], // rest of your config
} satisfies NextAuthOptions

// Use it in server contexts
export function auth(...args: [GetServerSidePropsContext["req"], GetServerSidePropsContext["res"]] | [NextApiRequest, NextApiResponse] | []) {
return getServerSession(...args, config)
}

When calling from the server-side i.e. in Route Handlers, React Server Components, API routes or in getServerSideProps, we recommend using this function instead of getSession to retrieve the session object. This method is especially useful when you are using NextAuth.js with a database. This method can drastically reduce response time when used over getSession on server-side, due to avoiding an extra fetch to an API Route (this is generally not recommended in Next.js). In addition, getServerSession will correctly update the cookie expiry time and update the session content if callbacks.jwt or callbacks.session changed something.

getServerSession requires passing the same object you would pass to NextAuth when initializing NextAuth.js. To do so, you can export your NextAuth.js options in the following way:

In [...nextauth].ts:

import NextAuth from 'next-auth'
import type { NextAuthOptions } from 'next-auth'

export const authOptions: NextAuthOptions = {
// your configs
}

export default NextAuth(authOptions);

In getServerSideProps:

import { authOptions } from 'pages/api/auth/[...nextauth]'
import { getServerSession } from "next-auth/next"

export async function getServerSideProps(context) {
const session = await getServerSession(context.req, context.res, authOptions)

if (!session) {
return {
redirect: {
destination: '/',
permanent: false,
},
}
}

return {
props: {
session,
},
}
}

In API Routes:

import { authOptions } from 'pages/api/auth/[...nextauth]'
import { getServerSession } from "next-auth/next"


export default async function handler(req, res) {
const session = await getServerSession(req, res, authOptions)

if (!session) {
res.status(401).json({ message: "You must be logged in." });
return;
}

return res.json({
message: 'Success',
})
}

In App Router:

You can also use getServerSession in Next.js' server components:

import { getServerSession } from "next-auth/next"
import { authOptions } from "pages/api/auth/[...nextauth]"

export default async function Page() {
const session = await getServerSession(authOptions)
return <pre>{JSON.stringify(session, null, 2)}</pre>
}
info

In contrast to useSession, which will return a session object whether or not a user has logged in (whether or not cookies are present), getServerSession only returns a session object when a user has logged in (only when authenticated cookies are present), otherwise, it returns null.

danger

Currently, the underlying Next.js cookies() method only provides read access to the request cookies. This means that the expires value is stripped away from session in Server Components. Furthermore, there is a hard expiry on sessions, after which the user will be required to sign in again. (The default expiry is 30 days).

Caching

Note that using this function implies personalized data and that you should not store pages or APIs using this in a public cache. For example a host like Vercel will implicitly prevent you from caching publicly due to the set-cookie header set by this function.

unstable_getServerSession

This method was renamed to getServerSession. See the documentation above.

Middleware

You can use a Next.js Middleware with NextAuth.js to protect your site.

Next.js 12 has introduced Middleware. It is a way to run logic before accessing any page, even when they are static. On platforms like Vercel, Middleware is run at the Edge.

If the following options look familiar, this is because they are a subset of these options. You can extract these to a common configuration object to reuse them. In the future, we would like to be able to run everything in Middleware. (See Caveats).

You can get the withAuth middleware function from next-auth/middleware either as a default or a named import:

Prerequisites

You must set the same secret in the middleware that you use in NextAuth. The easiest way is to set the NEXTAUTH_SECRET environment variable. It will be picked up by both the NextAuth config, as well as the middleware config.

Alternatively, you can provide the secret using the secret option in the middleware config.

We strongly recommend replacing the secret value completely with this NEXTAUTH_SECRET environment variable.

Basic usage

The most simple usage is when you want to require authentication for your entire site. You can add a middleware.js file with the following:

export { default } from "next-auth/middleware"

That's it! Your application is now secured. 🎉

If you only want to secure certain pages, export a config object with a matcher:

export { default } from "next-auth/middleware"

export const config = { matcher: ["/dashboard"] }

Now you will still be able to visit every page, but only /dashboard will require authentication.

If a user is not logged in, the default behavior is to redirect them to the sign-in page.


callbacks

  • Required: No

Description

Callbacks are asynchronous functions you can use to control what happens when an action is performed.

Example (default value)

 callbacks: {
authorized({ req , token }) {
if(token) return true // If there is a token, the user is authenticated
}
}

pages

  • Required: No

Description

Specify URLs to be used if you want to create custom sign-in and error pages. The pages specified will override the corresponding built-in page.

info

The pages configuration should match the same configuration in [...nextauth].ts. This is so that the next-auth Middleware is aware of your custom pages, so it won't end up redirecting to itself when an unauthenticated condition is met.

Example (default value)

import { withAuth } from "next-auth/middleware"

export default withAuth({
// Matches the pages config in `[...nextauth]`
pages: {
signIn: '/login',
error: '/error',
}
})

For more information, see the documentation for the pages option.


secret

  • Required: No

Description

The same secret is used in the NextAuth.js config.

Example (default value)

secret: process.env.NEXTAUTH_SECRET

Advanced usage

NextAuth.js Middleware is very flexible, there are multiple ways to use it.

note

If you do not define the options, NextAuth.js will use the default values for the omitted options.

wrap middleware

middleware.ts
import { withAuth } from "next-auth/middleware"

export default withAuth(
// `withAuth` augments your `Request` with the user's token.
function middleware(req) {
console.log(req.nextauth.token)
},
{
callbacks: {
authorized: ({ token }) => token?.role === "admin",
},
}
)

export const config = { matcher: ["/admin"] }

The middleware function will only be invoked if the authorized callback returns true.


Custom JWT decode method

If you have a custom jwt decode method set in [...nextauth].ts, you must also pass the same decode method to withAuth in order to read the custom-signed JWT correctly. You may want to extract the encode/decode logic to a separate function for consistency.

/api/auth/[...nextauth].ts
import type { NextAuthOptions } from "next-auth"
import NextAuth from "next-auth"
import jwt from "jsonwebtoken"

export const authOptions: NextAuthOptions = {
providers: [...],
jwt: {
async encode({ secret, token }) {
return jwt.sign(token, secret)
},
async decode({ secret, token }) {
return jwt.verify(token, secret)
},
},
}

export default NextAuth(authOptions)

And:

middleware.ts
import withAuth from "next-auth/middleware"
import { authOptions } from "pages/api/auth/[...nextauth]";

export default withAuth({
jwt: { decode: authOptions.jwt?.decode },
callbacks: {
authorized: ({ token }) => !!token,
},
})

Caveats

  • Currently only supports session verification, as parts of the sign-in code need to run in a Node.js environment. In the future, we would like to make sure that NextAuth.js can fully run at the Edge
  • Only supports the "jwt" session strategy. We need to wait until databases at the Edge become mature enough to ensure a fast experience. (If you know of an Edge-compatible database, we would like if you proposed a new Adapter)