Sign in with Keycloak

To enable Keycloak Auth for your project, you need to set up an Keycloak OAuth application and add the application credentials to your Supabase Dashboard.

Overview

To get started with Keycloak, you can run it in a docker container with: docker run -p 8080:8080 -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=admin quay.io/keycloak/keycloak:latest start-dev

This guide will be assuming that you are running Keycloak in a docker container as described in the command above.

Keycloak OAuth consists of five broad steps:

Create a new client in your specified Keycloak realm.
Obtain the issuer from the "OpenID Endpoint Configuration". This will be used as the Keycloak URL.
Ensure that the new client has the "Client Protocol" set to openid-connect and the "Access Type" is set to "confidential".
The Client ID of the client created will be used as the client id.
Obtain the Secret from the credentials tab which will be used as the client secret.
Add the callback URL of your application to your allowlist.

Access your Keycloak admin console

Create a Keycloak realm

Once you've signed in to the Keycloak console, you can add a realm from the side panel. The default realm should be named "Master".
After you've added a new realm, you can retrieve the issuer from the "OpenID Endpoint Configuration" endpoint. The issuer will be used as the Keycloak URL.
You can find this endpoint from the realm settings under the "General Tab" or visit http://localhost:8080/realms/my_realm_name/.well-known/openid-configuration

Add a Keycloak Realm.

Create a Keycloak client

The "Client ID" of the created client will serve as the client_id when you make API calls to authenticate the user.

Add a Keycloak client

Client settings

After you've created the client successfully, ensure that you set the following settings:

The "Client Protocol" should be set to openid-connect.
The "Access Type" should be set to "confidential".
The "Valid Redirect URIs" should be set to: https://<project-ref>.supabase.co/auth/v1/callback.

Obtain the client id, set the client protocol and access type Set redirect uri

Obtain the client secret

This will serve as the client_secret when you make API calls to authenticate the user. Under the "Credentials" tab, the Secret value will be used as the client secret.

Obtain the client secret

Since Keycloak version 22, the openid scope must be passed. Add this to the supabase.auth.signInWithOAuth() method.

JavaScript

Flutter

Kotlin

Note

Make sure you're using the right supabase client in the following code.

If you're not using Server-Side Rendering or cookie-based Auth, you can directly use the createClient from @supabase/supabase-js. If you're using Server-Side Rendering, see the Server-Side Auth guide for instructions on creating your Supabase client.

When your user signs in, call signInWithOAuth() with keycloak as the provider:

import { createClient } from '@supabase/supabase-js'

const supabase = createClient('https://your-project-id.supabase.co', 'sb_publishable_...')

// ---cut---
async function signInWithKeycloak() {
  const { data, error } = await supabase.auth.signInWithOAuth({
    provider: 'keycloak',
    options: {
      scopes: 'openid',
    },
  })
}

When your user signs in, call signInWithOAuth() with keycloak as the provider:

Future<void> signInWithKeycloak() async {
  await supabase.auth.signInWithOAuth(
    OAuthProvider.keycloak,
    redirectTo: kIsWeb ? null : 'my.scheme://my-host', // Optionally set the redirect link to bring back the user via deeplink.
    authScreenLaunchMode:
        kIsWeb ? LaunchMode.platformDefault : LaunchMode.externalApplication, // Launch the auth screen in a new webview on mobile.
  );
}

When your user signs in, call signInWith(Provider) with Keycloak as the Provider:

suspend fun signInWithKeycloak() {
	supabase.auth.signInWith(Keycloak) {
		scopes.add("openid")
	}
}

When your user signs in, call SignIn() with Provider.KeyCloak as the provider:

var state = await supabase.Auth.SignIn(Provider.KeyCloak, new SignInOptions { Scopes = "openid" });
var signInUrl = state.Uri;

For a PKCE flow, for example in Server-Side Auth, you need an extra step to handle the code exchange. When calling signInWithOAuth, provide a redirectTo URL which points to a callback route. This redirect URL should be added to your redirect allow list.

Client

Server

In the browser, signInWithOAuth automatically redirects to the OAuth provider's authentication endpoint, which then redirects to your endpoint.

import { createClient, type Provider } from '@supabase/supabase-js';
const supabase = createClient('https://your-project-id.supabase.co', 'sb_publishable_...')
const provider = 'provider' as Provider

// ---cut---
await supabase.auth.signInWithOAuth({
  provider,
  options: {
    redirectTo: `http://example.com/auth/callback`,
  },
})

In the server, you need to handle the redirect to the OAuth provider's authentication endpoint. The signInWithOAuth method returns the endpoint URL, which you can redirect to.

Caution

Use a server client from @supabase/ssr, and send its cookies with the redirect. signInWithOAuth stores the PKCE code verifier in a cookie. When that Set-Cookie header doesn't reach the browser, the callback can't exchange the code for a session.

import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr'
import type { Provider } from '@supabase/supabase-js'

// A route handler that receives the incoming Request
async function handler(request: Request) {
  const headers = new Headers()
  const provider = 'provider' as Provider

  const supabase = createServerClient('https://your-project-id.supabase.co', 'sb_publishable_...', {
    cookies: {
      getAll() {
        return parseCookieHeader(request.headers.get('Cookie') ?? '') as {
          name: string
          value: string
        }[]
      },
      setAll(cookiesToSet, cacheHeaders) {
        cookiesToSet.forEach(({ name, value, options }) =>
          headers.append('Set-Cookie', serializeCookieHeader(name, value, options))
        )
        Object.entries(cacheHeaders).forEach(([key, value]) => headers.set(key, value))
      },
    },
  })

  const { data, error } = await supabase.auth.signInWithOAuth({
    provider,
    options: {
      redirectTo: 'http://example.com/auth/callback',
    },
  })

  if (error) {
    throw error
  }

  // Redirect with `headers` so the browser stores the code verifier cookie.
  // Frameworks usually wrap this, for example `redirect(data.url, { headers })` in Remix.
  headers.set('Location', data.url)
  return new Response(null, { status: 303, headers })
}

When your framework sets cookies on the response for you, such as cookies() in Next.js or event.cookies in SvelteKit, write to that API in setAll instead. The cookie is then already on the response, and the redirect needs no extra headers.

At the callback endpoint, handle the code exchange to save the user session.

Next.js

SvelteKit

Astro

Remix

Express

Create a new file at app/auth/callback/route.ts and populate with the following:

import { NextResponse } from 'next/server'

// The client you created from the Server-Side Auth instructions
import { createClient } from '@/utils/supabase/server'

export async function GET(request: Request) {
  const { searchParams, origin } = new URL(request.url)
  const code = searchParams.get('code')
  // if "next" is in param, use it as the redirect URL
  let next = searchParams.get('next') ?? '/'
  if (!next.startsWith('/')) {
    // if "next" is not a relative URL, use the default
    next = '/'
  }

  if (code) {
    const supabase = await createClient()
    const { error } = await supabase.auth.exchangeCodeForSession(code)
    if (!error) {
      const forwardedHost = request.headers.get('x-forwarded-host') // original origin before load balancer
      const isLocalEnv = process.env.NODE_ENV === 'development'
      if (isLocalEnv) {
        // we can be sure that there is no load balancer in between, so no need to watch for X-Forwarded-Host
        return NextResponse.redirect(`${origin}${next}`)
      } else if (forwardedHost) {
        return NextResponse.redirect(`https://${forwardedHost}${next}`)
      } else {
        return NextResponse.redirect(`${origin}${next}`)
      }
    }
  }

  // return the user to an error page with instructions
  return NextResponse.redirect(`${origin}/auth/auth-code-error`)
}

Create a new file at src/routes/auth/callback/+server.js and populate with the following:

import { redirect } from '@sveltejs/kit'

export const GET = async (event) => {
  const {
    url,
    locals: { supabase },
  } = event
  const code = url.searchParams.get('code')
  const next = url.searchParams.get('next') ?? '/'

  if (code) {
    const { error } = await supabase.auth.exchangeCodeForSession(code)
    if (!error) {
      redirect(303, `/${next.slice(1)}`)
    }
  }

  // return the user to an error page with instructions
  redirect(303, '/auth/auth-code-error')
}

Create a new file at src/pages/auth/callback.ts and populate with the following:

import { createServerClient, parseCookieHeader } from '@supabase/ssr'
import { type APIRoute } from 'astro'

export const GET: APIRoute = async ({ request, cookies, redirect }) => {
  const requestUrl = new URL(request.url)
  const code = requestUrl.searchParams.get('code')
  const next = requestUrl.searchParams.get('next') || '/'

  if (code) {
    const supabase = createServerClient(
      import.meta.env.PUBLIC_SUPABASE_URL,
      import.meta.env.PUBLIC_SUPABASE_PUBLISHABLE_KEY,
      {
        cookies: {
          getAll() {
            return parseCookieHeader(Astro.request.headers.get('Cookie') ?? '')
          },
          setAll(cookiesToSet, _headers) {
            cookiesToSet.forEach(({ name, value, options }) =>
              Astro.cookies.set(name, value, options)
            )
          },
        },
      }
    )

    const { error } = await supabase.auth.exchangeCodeForSession(code)

    if (!error) {
      return redirect(next)
    }
  }

  // return the user to an error page with instructions
  return redirect('/auth/auth-code-error')
}

Create a new file at app/routes/auth.callback.tsx and populate with the following:

import { redirect, type LoaderFunctionArgs } from '@remix-run/node'
import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr'

export async function loader({ request }: LoaderFunctionArgs) {
  const requestUrl = new URL(request.url)
  const code = requestUrl.searchParams.get('code')
  const next = requestUrl.searchParams.get('next') || '/'
  const responseHeaders = new Headers()

  if (code) {
    const supabase = createServerClient(
      process.env.SUPABASE_URL!,
      process.env.SUPABASE_PUBLISHABLE_KEY!,
      {
        cookies: {
          getAll() {
            return parseCookieHeader(request.headers.get('Cookie') ?? '')
          },
          setAll(cookiesToSet, cacheHeaders) {
            cookiesToSet.forEach(({ name, value, options }) =>
              responseHeaders.append('Set-Cookie', serializeCookieHeader(name, value, options))
            )
            Object.entries(cacheHeaders).forEach(([key, value]) => responseHeaders.set(key, value))
          },
        },
      }
    )

    const { error } = await supabase.auth.exchangeCodeForSession(code)

    if (!error) {
      return redirect(next, { headers: responseHeaders })
    }
  }

  // return the user to an error page with instructions
  return redirect('/auth/auth-code-error', { headers: responseHeaders })
}

Create a new route in your express app and populate with the following:

...
app.get("/auth/callback", async function (req, res) {
  const code = req.query.code
  const next = req.query.next ?? "/"

  if (code) {
    const supabase = createServerClient(
      process.env.SUPABASE_URL,
      process.env.SUPABASE_PUBLISHABLE_KEY, {
    cookies: {
      getAll() {
        return parseCookieHeader(req.headers.cookie ?? '')
      },
      setAll(cookiesToSet, headers) {
        cookiesToSet.forEach(({ name, value, options }) =>
          res.appendHeader('Set-Cookie', serializeCookieHeader(name, value, options))
        )
        Object.entries(headers).forEach(([key, value]) =>
          res.setHeader(key, value)
        )
      },
    },
  })
    await supabase.auth.exchangeCodeForSession(code)
  }

  res.redirect(303, `/${next.slice(1)}`)
})

JavaScript

Flutter

Kotlin

When your user signs out, call signOut() to remove them from the browser session and any objects from localStorage:

async function signOut() {
  const { error } = await supabase.auth.signOut()
}

When your user signs out, call signOut() to remove them from the browser session and any objects from localStorage:

Future<void> signOut() async {
  await supabase.auth.signOut();
}

When your user signs out, call signOut() to remove them from the browser session and any objects from localStorage:

import { createClient } from '@supabase/supabase-js';
const supabase = createClient('https://your-project-id.supabase.co', 'sb_publishable_...');

// ---cut---
suspend fun signOut() {
	supabase.auth.signOut()
}

When your user signs out, call SignOut() to remove them from the browser session and any objects from local storage:

await supabase.Auth.SignOut();

Resources

You can find the Keycloak OpenID endpoint configuration under the realm settings.

Overview

Access your Keycloak admin console

Create a Keycloak realm

Create a Keycloak client

Client settings

Obtain the client secret

Add sign-in code to your client app

Resources