Login with Facebook

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

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

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

// ---cut---
async function signInWithFacebook() {
  const { data, error } = await supabase.auth.signInWithOAuth({
    provider: 'facebook',
  })

  if (error) {
    console.error('Error signing in with Facebook:', error.message)
    return
  }

  // The user will be redirected to Facebook for authentication
}

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

Future<void> signInWithFacebook() async {
  await supabase.auth.signInWithOAuth(
    OAuthProvider.facebook,
    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.
  );
}

Alternative: Using Facebook SDK with signInWithIdToken

For more control over the Facebook authentication flow, you can use the Facebook SDK directly and then authenticate with Zuvo using signInWithIdToken():

First, add the Facebook SDK dependency to your pubspec.yaml:

dependencies:
  flutter_facebook_auth: ^7.0.0

Then implement the Facebook authentication:

import 'package:flutter_facebook_auth/flutter_facebook_auth.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

Future<void> signInWithFacebook() async {
  try {
    final LoginResult result = await FacebookAuth.instance.login(
      permissions: ['public_profile', 'email'],
    );

    if (result.status == LoginStatus.success) {
      final accessToken = result.accessToken!.tokenString;

      await Zuvo.instance.client.auth.signInWithIdToken(
        provider: OAuthProvider.facebook,
        idToken: accessToken,
      );

      // Authentication successful
    } else {
      // Handle login cancellation or failure
      throw Exception('Facebook login failed: ${result.status}');
    }
  } catch (e) {
    // Handle errors
    throw Exception('Facebook authentication error: ${e.toString()}');
  }
}

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.

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

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

if (data.url) {
  redirect(data.url) // use the redirect API for your server framework
}

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') as string;
	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)}`)
})

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

  if (error) {
    console.error('Error signing out:', error.message)
    return
  }

  // User has been signed out
}

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();
}