Role-based access control

There are two ways to add role-based access control (RBAC) to your application with Auth.js, based on the session strategy you choose. Let’s see an example for each of these.

Getting the role

Start by adding a profile() callback to the providers’ config to determine the user role:

./auth.ts

import NextAuth from "next-auth"
import Google from "next-auth/providers/google"
 
export const { handlers, auth } = NextAuth({
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      },
    })
  ],
})

/src/routes/plugin@auth.ts

import { QwikAuth$ } from "@auth/qwik"
import Google from "@auth/qwik/providers/google"
 
export const { onRequest, useSession, useSignIn, useSignOut } = QwikAuth$(
  () => ({
    providers: [
      Google({
        profile(profile) {
          return { role: profile.role ?? "user", ... }
        },
      })
    ],
  })
)

./src/auth.ts

import SvelteKitAuth from "@auth/sveltekit"
import Google from "@auth/sveltekit/providers/google"
 
export const { handle } = SvelteKitAuth({
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      },
    })
  ],
})

💡

Determining the users role is your responsibility, you can either add your own logic or if your provider returns a role you can use that instead.

Persisting the role

Persisting the role will be different depending on the session strategy you’re using. If you don’t know which session strategy you’re using, then most likely you’re using JWT (the default one).

With JWT

When you don’t have a database configured, the role will be persisted in a cookie, by using the jwt() callback. On sign-in, the role property is exposed from the profile callback on the user object. Persist the user.role value by assigning it to token.role. That’s it!

If you also want to use the role on the client, you can expose it via the session callback.

./auth.ts

import NextAuth from "next-auth"
import Google from "next-auth/providers/google"
 
export const { handlers, auth } = NextAuth({
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      },
    })
  ],
  callbacks: {
    jwt({ token, user }) {
      if(user) token.role = user.role
      return token
    },
    session({ session, token }) {
      session.user.role = token.role
      return session
    }
  }
})

/src/routes/plugin@auth.ts

import { QwikAuth$ } from "@auth/qwik"
import Google from "@auth/qwik/providers/google"
 
export const { onRequest, useSession, useSignIn, useSignOut } = QwikAuth$(
  () => ({
    providers: [
      Google({
        profile(profile) {
          return { role: profile.role ?? "user", ... }
        },
      })
    ],
    callbacks: {
      jwt({ token, user }) {
        if(user) token.role = user.role
        return token
      },
      session({ session, token }) {
        session.user.role = token.role
        return session
      }
    }
  })
)

./src/auth.ts

import SvelteKitAuth from "@auth/sveltekit"
import Google from "@auth/sveltekit/providers/google"
 
export const { handle } = SvelteKitAuth({
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      },
    })
  ],
  callbacks: {
    jwt({ token, user }) {
      if(user) token.role = user.role
      return token
    },
    session({ session, token }) {
      session.user.role = token.role
      return session
    }
  }
})

With this strategy, if you want to update the role, the user needs to be forced to sign in again.

With Database

When you have a database, you can save the user role on the User model. The below example is showing you how to do this with Prisma, but the idea is the same for all adapters.

First, add a role column to the User model.

/prisma/schema.prisma

model User {
  id            String    @id @default(cuid())
  name          String?
  email         String?   @unique
  emailVerified DateTime?
  image         String?
  role          String?  // New column
  accounts      Account[]
  sessions      Session[]
}

The profile() callback’s return value is used to create users in the database. That’s it! Your newly created users will now have an assigned role.

If you also want to use the role on the client, you can expose it via the session callback.

./auth.ts

import NextAuth from "next-auth"
import Google from "next-auth/providers/google"
import prisma from "lib/prisma"
 
export const { handlers, auth } = NextAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      }
    })
  ],
  callbacks: {
    session({ session, user }) {
      session.user.role = user.role
      return session
    }
  }
})

/src/routes/plugin@auth.ts

import { QwikAuth$ } from "@auth/qwik"
import { PrismaAdapter } from "@auth/prisma-adapter"
import { PrismaClient } from "@prisma/client"
 
const prisma = new PrismaClient()
 
export const { onRequest, useSession, useSignIn, useSignOut } = QwikAuth$(
  () => ({
    providers: [],
    adapter: PrismaAdapter(prisma),
    callbacks: {
      session({ session, user }) {
        session.user.role = user.role
        return session
      },
    },
  })
)

./src/auth.ts

import SvelteKitAuth from "@auth/sveltekit"
import Google from "@auth/sveltekit/providers/google"
import prisma from "lib/prisma"
 
export const { handle, auth } = SvelteKitAuth({
  adapter: PrismaAdapter(prisma),
  providers: [
    Google({
      profile(profile) {
        return { role: profile.role ?? "user", ... }
      }
      ...
    })
  ],
  callbacks: {
    session({ session, user }) {
      session.user.role = user.role
      return session
    }
  }
})

src/hooks.server.ts

export { handle } from "./auth"

It is up to you how you want to manage to update the roles, either through direct database access or building your role update API.

Using the role

The user can access the information stored in the current session through the authorization function exported from the configuration file of the respective framework. This function retrieves information exposed via the session and jwt callbacks in the configuration file. With this information, you can implement different strategies and logic to display the UI based on your needs.

To get the data on the server side, you should import the auth function from the configuration file and verify if the user has the expected role.

./app/admin/page.tsx

import { auth } from "@/auth";
 
export default async function Page() {
  const session = await auth();
 
  if (session?.user?.role === "admin") {
    return <p>You are an admin, welcome!</p>;
  }
 
  return <p>You are not authorized to view this page!</p>;
}

If you want to use the role on the client side, use the useSession hook. The session.user.role will contain the required role if you exposed it via the session callback.

./app/admin/page.tsx

"use client"
import { useSession } from "next-auth/react";
 
export default function Page() {
  const session = useSession();
 
  if (session?.user?.role === "admin") {
    return <p>You are an admin, welcome!</p>;
  }
 
  return <p>You are not authorized to view this page!</p>;
}

/src/routes/plugin@auth.ts

export const onRequest: RequestHandler = (event) => {
  const session = event.sharedMap.get("session")
  if (!session || new Date(session.expires) < new Date()) {
    throw event.redirect(302, `/auth/signin?redirectTo=${event.url.pathname}`)
  }
 
  return session
}

./routes/+page.server.ts

import { redirect } from "@sveltejs/kit"
 
export const load: PageServerLoad = async (event) => {
  const session = await event.locals.auth()
 
  if (!session && event.url.pathname !== "/login") {
    const fromUrl = event.url.pathname + event.url.search
    redirect(307, `/login?redirectTo=${encodeURIComponent(fromUrl)}`)
  }
 
  return {
    session,
  }
}

💡

When using Next.js and JWT, you can alternatively also use Middleware to redirect the user based on their role, even before rendering the page.

Resources

Restricting users accessing to the app Supporting Corporate Proxies

Role-based access control

Getting the role

Persisting the role

With JWT

With Database

Using the role

Resources

About Auth.js

Download

Acknowledgements