Auth

Setting up Server-Side Auth for Next.js


Next.js comes in two flavors: the App Router and the Pages Router. You can set up Server-Side Auth with either strategy. You can even use both in the same application.

1

Install Supabase packages

Install the @supabase/supabase-js package and the helper @supabase/ssr package.


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npm install @supabase/supabase-js @supabase/ssr

2

Set up environment variables

Create a .env.local file in your project root directory.

Fill in your NEXT_PUBLIC_SUPABASE_URL and NEXT_PUBLIC_SUPABASE_ANON_KEY:

Project URL
Anon key
.env.local

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NEXT_PUBLIC_SUPABASE_URL=<your_supabase_project_url>
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NEXT_PUBLIC_SUPABASE_ANON_KEY=<your_supabase_anon_key>

3

Write utility functions to create Supabase clients

To access Supabase from your Next.js app, you need 2 types of Supabase clients:

  1. Client Component client - To access Supabase from Client Components, which run in the browser.
  2. Server Component client - To access Supabase from Server Components, Server Actions, and Route Handlers, which run only on the server.

Create a utils/supabase folder with a file for each type of client. Then copy the utility functions for each client type.

utils/supabase/client.ts
utils/supabase/server.ts

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import { createBrowserClient } from '@supabase/ssr'
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export function createClient() {
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return createBrowserClient(
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process.env.NEXT_PUBLIC_SUPABASE_URL!,
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process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
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)
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}

4

Hook up middleware

Create a middleware.ts file at the root of your project.

Since Server Components can't write cookies, you need middleware to refresh expired Auth tokens and store them.

The middleware is responsible for:

  1. Refreshing the Auth token (by calling supabase.auth.getUser).
  2. Passing the refreshed Auth token to Server Components, so they don't attempt to refresh the same token themselves. This is accomplished with request.cookies.set.
  3. Passing the refreshed Auth token to the browser, so it replaces the old token. This is accomplished with response.cookies.set.

Copy the middleware code for your app.

Add a matcher so the middleware doesn't run on routes that don't access Supabase.

middleware.ts
utils/supabase/middleware.ts

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import { type NextRequest } from 'next/server'
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import { updateSession } from '@/utils/supabase/middleware'
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export async function middleware(request: NextRequest) {
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return await updateSession(request)
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}
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export const config = {
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matcher: [
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/*
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* Match all request paths except for the ones starting with:
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* - _next/static (static files)
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* - _next/image (image optimization files)
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* - favicon.ico (favicon file)
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* Feel free to modify this pattern to include more paths.
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*/
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'/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
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],
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}

5

Create a login page

Create a login page for your app. Use a Server Action to call the Supabase signup function.

Since Supabase is being called from an Action, use the client defined in @/utils/supabase/server.ts.

app/login/page.tsx
app/login/actions.ts
app/error/page.tsx

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import { login, signup } from './actions'
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export default function LoginPage() {
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return (
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<form>
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<label htmlFor="email">Email:</label>
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<input id="email" name="email" type="email" required />
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<label htmlFor="password">Password:</label>
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<input id="password" name="password" type="password" required />
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<button formAction={login}>Log in</button>
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<button formAction={signup}>Sign up</button>
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</form>
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)
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}

6

Change the Auth confirmation path

If you have email confirmation turned on (the default), a new user will receive an email confirmation after signing up.

Change the email template to support a server-side authentication flow.

Go to the Auth templates page in your dashboard. In the Confirm signup template, change {{ .ConfirmationURL }} to {{ .SiteURL }}/auth/confirm?token_hash={{ .TokenHash }}&type=signup.

7

Create a route handler for Auth confirmation

Create a Route Handler for auth/confirm. When a user clicks their confirmation email link, exchange their secure code for an Auth token.

Since this is a Router Handler, use the Supabase client from @/utils/supabase/server.ts.

app/auth/confirm/route.ts

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import { type EmailOtpType } from '@supabase/supabase-js'
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import { type NextRequest, NextResponse } from 'next/server'
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import { createClient } from '@/utils/supabase/server'
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export async function GET(request: NextRequest) {
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const { searchParams } = new URL(request.url)
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const token_hash = searchParams.get('token_hash')
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const type = searchParams.get('type') as EmailOtpType | null
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const next = searchParams.get('next') ?? '/'
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const redirectTo = request.nextUrl.clone()
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redirectTo.pathname = next
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redirectTo.searchParams.delete('token_hash')
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redirectTo.searchParams.delete('type')
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if (token_hash && type) {
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const supabase = createClient()
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const { error } = await supabase.auth.verifyOtp({
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type,
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token_hash,
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})
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if (!error) {
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redirectTo.searchParams.delete('next')
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return NextResponse.redirect(redirectTo)
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}
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}
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// return the user to an error page with some instructions
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redirectTo.pathname = '/error'
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return NextResponse.redirect(redirectTo)
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}

8

Access user info from Server Component

Server Components can read cookies, so you can get the Auth status and user info.

Since you're calling Supabase from a Server Component, use the client created in @/utils/supabase/server.ts.

Create a private page that users can only access if they're logged in. The page displays their email.

app/private/page.tsx

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import { redirect } from 'next/navigation'
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import { createClient } from '@/utils/supabase/server'
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export default async function PrivatePage() {
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const supabase = createClient()
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const { data, error } = await supabase.auth.getUser()
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if (error || !data?.user) {
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redirect('/login')
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}
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return <p>Hello {data.user.email}</p>
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}

Congratulations

You're done! To recap, you've successfully:

  • Called Supabase from a Server Action.
  • Called Supabase from a Server Component.
  • Set up a Supabase client utility to call Supabase from a Client Component. You can use this if you need to call Supabase from a Client Component, for example to set up a realtime subscription.
  • Set up middleware to automatically refresh the Supabase Auth session.

You can now use any Supabase features from your client or server code!