Build a User Management App with NextJS

This tutorial demonstrates how to build a basic user management app. The app authenticates and identifies the user, stores their profile information in the database, and allows the user to log in, update their profile details, and upload a profile photo. The app uses:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - users log in through magic links sent to their email (without having to set up passwords).
Supabase Storage - users can upload a profile photo.

note

If you get stuck while working through this guide, refer to the full example on GitHub.

Project setup#

Before we start building we're going to set up our Database and API. This is as simple as starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project#

Create a new project in the Supabase Dashboard.
Enter your project details.
Wait for the new database to launch.

Set up the database schema#

Now we are going to set up the database schema. We can use the "User Management Starter" quickstart in the SQL Editor, or you can just copy/paste the SQL from below and run it yourself.

Go to the SQL Editor page in the Dashboard.
Click User Management Starter.
Click Run.

Get the API Keys#

Now that you've created some database tables, you are ready to insert data using the auto-generated API. We just need to get the Project URL and anon key from the API settings.

Go to the API Settings page in the Dashboard.
Find your Project URL, anon, and service_role keys on this page.

Building the App#

Let's start building the Next.js app from scratch.

Initialize a Next.js app#

We can use create-next-app to initialize an app called supabase-nextjs:

npx create-next-app@latest --use-npm supabase-nextjs
cd supabase-nextjs

Then install the Supabase client library: supabase-js

npm install @supabase/supabase-js

And finally we want to save the environment variables in a .env.local. All we need are the API URL and the anon key that you copied earlier.

.env.local

NEXT_PUBLIC_SUPABASE_URL=YOUR_SUPABASE_URL
NEXT_PUBLIC_SUPABASE_ANON_KEY=YOUR_SUPABASE_ANON_KEY

And one optional step is to update the CSS file app/globals.css to make the app look nice. You can find the full contents of this file here.

Supabase Auth Helpers#

Next.js is a highly versatile framework offering pre-rendering at build time (SSG), server-side rendering at request time (SSR), API routes, and middleware edge-functions.

It can be challenging to authenticate your users in all these different environments, that's why we've created the Supabase Auth Helpers to make user management and data fetching within Next.js as easy as possible.

Install the auth helpers for Next.js

npm install @supabase/auth-helpers-nextjs

NextJS Middleware#

Create a middleware.js file and include the following content to:

Verify if there is an authenticated Supabase user
Validate if the user is authenticated and currently on the sign-in page, redirecting them to the account page
Verify if the user is not authenticated and currently on the account page, redirecting them to the sign-in page.

middleware.js

import { createMiddlewareClient } from '@supabase/auth-helpers-nextjs'
import { NextResponse } from 'next/server'
export async function middleware(req) {
  const res = NextResponse.next()
  const supabase = createMiddlewareClient({ req, res })
  const {
    data: { user },
  } = await supabase.auth.getUser()
  // if user is signed in and the current path is / redirect the user to /account
  if (user && req.nextUrl.pathname === '/') {
    return NextResponse.redirect(new URL('/account', req.url))
  }
  // if user is not signed in and the current path is not / redirect the user to /
  if (!user && req.nextUrl.pathname !== '/') {
    return NextResponse.redirect(new URL('/', req.url))
  }
  return res
}
export const config = {
  matcher: ['/', '/account'],
}

Supabase Auth UI

We can use the Supabase Auth UI a pre-built React component for authenticating users via OAuth, email, and magic links.

Install the Supabase Auth UI for React

npm install @supabase/auth-ui-react @supabase/auth-ui-shared

Create an AuthForm client side component with the Auth component rendered within it:

app/auth-form.jsx

'use client'
import { Auth } from '@supabase/auth-ui-react'
import { ThemeSupa } from '@supabase/auth-ui-shared'
import { createClientComponentClient } from '@supabase/auth-helpers-nextjs'
export default function AuthForm() {
  const supabase = createClientComponentClient()
  return (
    <Auth
      supabaseClient={supabase}
      view="magic_link"
      appearance={{ theme: ThemeSupa }}
      theme="dark"
      showLinks={false}
      providers={[]}
      redirectTo="http://localhost:3000/auth/callback"
    />
  )
}

note

If you are using TypeScript for this project, see generating types to automatically generate types from your database tables.

Add the AuthForm component to your home page

app/page.js

import AuthForm from './auth-form'
export default function Home() {
  return (
    <div className="row">
      <div className="col-6">
        <h1 className="header">Supabase Auth + Storage</h1>
        <p className="">
          Experience our Auth and Storage through a simple profile management example. Create a user
          profile and upload an avatar image. Fast, simple, secure.
        </p>
      </div>
      <div className="col-6 auth-widget">
        <AuthForm />
      </div>
    </div>
  )
}

Proof Key for Code Exchange (PKCE)#

As we are employing Proof Key for Code Exchange (PKCE) in our authentication flow, it is necessary to create a route handler responsible for exchanging the code for a session.

In the following code snippet, we perform the following steps:

Retrieve the code sent back from the Supabase Auth server using the code query parameter.
Exchange this code for a session, which we store in our chosen storage mechanism (in this case, cookies).
Finally, we redirect the user to the account page.

app/auth/callback/route.js

import { createRouteHandlerClient } from '@supabase/auth-helpers-nextjs'
import { cookies } from 'next/headers'
import { NextResponse } from 'next/server'
export async function GET(req) {
  const supabase = createRouteHandlerClient({ cookies })
  const { searchParams } = new URL(req.url)
  const code = searchParams.get('code')
  if (code) {
    await supabase.auth.exchangeCodeForSession(code)
  }
  return NextResponse.redirect(new URL('/account', req.url))
}

Sign out#

Let's create an route handler to handle the signout from the server side.

app/auth/signout/route.js

import { createRouteHandlerClient } from '@supabase/auth-helpers-nextjs'
import { cookies } from 'next/headers'
import { NextResponse } from 'next/server'
export async function POST(req) {
  const supabase = createRouteHandlerClient({ cookies })
  // Check if we have a session
  const {
    data: { session },
  } = await supabase.auth.getSession()
  if (session) {
    await supabase.auth.signOut()
  }
  return NextResponse.redirect(new URL('/', req.url), {
    status: 302,
  })
}

Account page#

After a user is signed in we can allow them to edit their profile details and manage their account.

Let's create a new component for that called AccountForm within the app/account folder.

app/account/account-form.jsx

'use client'
import { useCallback, useEffect, useState } from 'react'
import { createClientComponentClient } from '@supabase/auth-helpers-nextjs'
export default function AccountForm({ session }) {
  const supabase = createClientComponentClient()
  const [loading, setLoading] = useState(true)
  const [fullname, setFullname] = useState(null)
  const [username, setUsername] = useState(null)
  const [website, setWebsite] = useState(null)
  const [avatar_url, setAvatarUrl] = useState(null)
  const user = session?.user
  const getProfile = useCallback(async () => {
    try {
      setLoading(true)
      let { data, error, status } = await supabase
        .from('profiles')
        .select(`full_name, username, website, avatar_url`)
        .eq('id', user?.id)
        .single()
      if (error && status !== 406) {
        throw error
      }
      if (data) {
        setFullname(data.full_name)
        setUsername(data.username)
        setWebsite(data.website)
        setAvatarUrl(data.avatar_url)
      }
    } catch (error) {
      alert('Error loading user data!')
    } finally {
      setLoading(false)
    }
  }, [user, supabase])
  useEffect(() => {
    getProfile()
  }, [user, getProfile])
  async function updateProfile({
    username,
    website,
    avatar_url,
  }) {
    try {
      setLoading(true)
      let { error } = await supabase.from('profiles').upsert({
        id: user?.id as string,
        full_name: fullname,
        username,
        website,
        avatar_url,
        updated_at: new Date().toISOString(),
      })
      if (error) throw error
      alert('Profile updated!')
    } catch (error) {
      alert('Error updating the data!')
    } finally {
      setLoading(false)
    }
  }
  return (
    <div className="form-widget">
      <div>
        <label htmlFor="email">Email</label>
        <input id="email" type="text" value={session?.user.email} disabled />
      </div>
      <div>
        <label htmlFor="fullName">Full Name</label>
        <input
          id="fullName"
          type="text"
          value={fullname || ''}
          onChange={(e) => setFullname(e.target.value)}
        />
      </div>
      <div>
        <label htmlFor="username">Username</label>
        <input
          id="username"
          type="text"
          value={username || ''}
          onChange={(e) => setUsername(e.target.value)}
        />
      </div>
      <div>
        <label htmlFor="website">Website</label>
        <input
          id="website"
          type="url"
          value={website || ''}
          onChange={(e) => setWebsite(e.target.value)}
        />
      </div>
      <div>
        <button
          className="button primary block"
          onClick={() => updateProfile({ fullname, username, website, avatar_url })}
          disabled={loading}
        >
          {loading ? 'Loading ...' : 'Update'}
        </button>
      </div>
      <div>
        <form action="/auth/signout" method="post">
          <button className="button block" type="submit">
            Sign out
          </button>
        </form>
      </div>
    </div>
  )
}

Create a account page for the AccountForm component we just created

app/account/page.jsx

import { createServerComponentClient } from '@supabase/auth-helpers-nextjs'
import { cookies } from 'next/headers'
import AccountForm from './account-form'
export default async function Account() {
  const supabase = createServerComponentClient({ cookies })
  const {
    data: { session },
  } = await supabase.auth.getSession()
  return <AccountForm session={session} />
}

Launch!#

Now that we have all the pages, route handlers and components in place, let's run this in a terminal window:

npm run dev

And then open the browser to localhost:3000 and you should see the completed app.

Bonus: Profile photos#

Every Supabase project is configured with Storage for managing large files like photos and videos.

Let's create an avatar widget for the user so that they can upload a profile photo. We can start by creating a new component:

app/account/avatar.jsx

'use client'
import React, { useEffect, useState } from 'react'
import { createClientComponentClient } from '@supabase/auth-helpers-nextjs'
import Image from 'next/image'
export default function Avatar({ uid, url, size, onUpload }) {
  const supabase = createClientComponentClient()
  const [avatarUrl, setAvatarUrl] = useState(null)
  const [uploading, setUploading] = useState(false)
  useEffect(() => {
    async function downloadImage(path) {
      try {
        const { data, error } = await supabase.storage.from('avatars').download(path)
        if (error) {
          throw error
        }
        const url = URL.createObjectURL(data)
        setAvatarUrl(url)
      } catch (error) {
        console.log('Error downloading image: ', error)
      }
    }
    if (url) downloadImage(url)
  }, [url, supabase])
  const uploadAvatar = async (event) => {
    try {
      setUploading(true)
      if (!event.target.files || event.target.files.length === 0) {
        throw new Error('You must select an image to upload.')
      }
      const file = event.target.files[0]
      const fileExt = file.name.split('.').pop()
      const filePath = `${uid}-${Math.random()}.${fileExt}`
      let { error: uploadError } = await supabase.storage.from('avatars').upload(filePath, file)
      if (uploadError) {
        throw uploadError
      }
      onUpload(filePath)
    } catch (error) {
      alert('Error uploading avatar!')
    } finally {
      setUploading(false)
    }
  }
  return (
    <div>
      {avatarUrl ? (
        <Image
          width={size}
          height={size}
          src={avatarUrl}
          alt="Avatar"
          className="avatar image"
          style={{ height: size, width: size }}
        />
      ) : (
        <div className="avatar no-image" style={{ height: size, width: size }} />
      )}
      <div style={{ width: size }}>
        <label className="button primary block" htmlFor="single">
          {uploading ? 'Uploading ...' : 'Upload'}
        </label>
        <input
          style={{
            visibility: 'hidden',
            position: 'absolute',
          }}
          type="file"
          id="single"
          accept="image/*"
          onChange={uploadAvatar}
          disabled={uploading}
        />
      </div>
    </div>
  )
}

And then we can add the widget to the AccountForm component:

app/account/account-form.js

// Import the new component
import Avatar from './avatar'
// ...
return (
  <div className="form-widget">
    {/* Add to the body */}
    <Avatar
      uid={user.id}
      url={avatar_url}
      size={150}
      onUpload={(url) => {
        setAvatarUrl(url)
        updateProfile({ fullname, username, website, avatar_url: url })
      }}
    />
    {/* ... */}
  </div>
)

Storage management#

If you upload additional profile photos, they'll accumulate in the avatars bucket because of their random names with only the latest being referenced from public.profiles and the older versions getting orphaned.

To automatically remove obsolete storage objects, extend the database triggers. Note that it is not sufficient to delete the objects from the storage.objects table because that would orphan and leak the actual storage objects in the S3 backend. Instead, invoke the storage API within Postgres via the http extension.

Enable the http extension for the extensions schema in the Dashboard. Then, define the following SQL functions in the SQL Editor to delete storage objects via the API:

create or replace function delete_storage_object(bucket text, object text, out status int, out content text)
returns record
language 'plpgsql'
security definer
as $$
declare
  project_url text := '<YOURPROJECTURL>';
  service_role_key text := '<YOURSERVICEROLEKEY>'; --  full access needed
  url text := project_url||'/storage/v1/object/'||bucket||'/'||object;
begin
  select
      into status, content
           result.status::int, result.content::text
      FROM extensions.http((
    'DELETE',
    url,
    ARRAY[extensions.http_header('authorization','Bearer '||service_role_key)],
    NULL,
    NULL)::extensions.http_request) as result;
end;
$$;
create or replace function delete_avatar(avatar_url text, out status int, out content text)
returns record
language 'plpgsql'
security definer
as $$
begin
  select
      into status, content
           result.status, result.content
      from public.delete_storage_object('avatars', avatar_url) as result;
end;
$$;

Next, add a trigger that removes any obsolete avatar whenever the profile is updated or deleted:

create or replace function delete_old_avatar()
returns trigger
language 'plpgsql'
security definer
as $$
declare
  status int;
  content text;
begin
  if coalesce(old.avatar_url, '') <> ''
      and (tg_op = 'DELETE' or (old.avatar_url <> new.avatar_url)) then
    select
      into status, content
      result.status, result.content
      from public.delete_avatar(old.avatar_url) as result;
    if status <> 200 then
      raise warning 'Could not delete avatar: % %', status, content;
    end if;
  end if;
  if tg_op = 'DELETE' then
    return old;
  end if;
  return new;
end;
$$;
create trigger before_profile_changes
  before update of avatar_url or delete on public.profiles
  for each row execute function public.delete_old_avatar();

Finally, delete the public.profile row before a user is deleted. If this step is omitted, you won't be able to delete users without first manually deleting their avatar image.

create or replace function delete_old_profile()
returns trigger
language 'plpgsql'
security definer
as $$
begin
  delete from public.profiles where id = old.id;
  return old;
end;
$$;
create trigger before_delete_user
  before delete on auth.users
  for each row execute function public.delete_old_profile();

At this stage you have a fully functional application!

Build a User Management App with NextJS

Project setup#

Create a project#

Set up the database schema#

Get the API Keys#

Building the App#

Initialize a Next.js app#

Supabase Auth Helpers#

NextJS Middleware#

Supabase Auth UI

Proof Key for Code Exchange (PKCE)#

Sign out#

Account page#

Launch!#

Bonus: Profile photos#

Create an upload widget#

Add the new widget#

Storage management#

See also#

Build a User Management App with NextJS

Project setup#

Create a project#

Set up the database schema#

Get the API Keys#

Building the App#

Initialize a Next.js app#

Supabase Auth Helpers#

NextJS Middleware#

Set up a Login component#

Supabase Auth UI

Proof Key for Code Exchange (PKCE)#

Sign out#

Account page#

Launch!#

Bonus: Profile photos#

Create an upload widget#

Add the new widget#

Storage management#

See also#