Facebook sign-in in Firebase - Commands & Configuration

Introduction

Facebook sign-in lets users log into your app using their Facebook account. This makes login easier because users don't need to create a new password. It also helps you know who your users are.

When you want to let users quickly access your app without creating a new account.

When you want to use Facebook profile info to personalize your app experience.

When you want to reduce the number of passwords users must remember.

When you want to increase sign-up rates by offering popular social login options.

When you want to manage user authentication securely without building your own system.

Config File - firebase.json

firebase.json

{
  "hosting": {
    "public": "public",
    "ignore": ["firebase.json", "**/.*", "**/node_modules/**"]
  }
}

This file configures Firebase Hosting. Facebook sign-in is enabled in the Firebase console or via the Firebase Authentication settings, not directly in firebase.json.

Commands

Log in to your Firebase account from the command line to manage your projects.

Terminal

firebase login

Expected Output

✔  Success! Logged in as [e-mail]

Initialize Firebase Authentication in your project to set up sign-in methods.

Terminal

firebase init auth

Expected Output

=== Authentication Setup ===

✔  Authentication enabled

✔  Facebook sign-in enabled

Firebase Authentication has been initialized.

Deploy the authentication configuration including Facebook sign-in to Firebase.

Terminal

firebase deploy --only auth

Expected Output

=== Deploying to 'your-project-id' ===



✔  auth: Facebook sign-in enabled



✔  Deploy complete!



Project Console: https://console.firebase.google.com/project/your-project-id/overview

→

--only - Deploy only the specified Firebase feature, here 'auth' for authentication.

Import Facebook app credentials to Firebase Authentication to enable Facebook sign-in.

Terminal

firebase auth:import facebook-config.json

Expected Output

✔  Facebook app credentials imported successfully

Key Concept

If you remember nothing else from this pattern, remember: enabling Facebook sign-in in Firebase requires configuring the provider in your Firebase project and deploying the settings.

Common Mistakes

Not enabling Facebook sign-in in the Firebase console or config file.

Without enabling, users cannot log in with Facebook even if your app tries to use it.

Always enable Facebook as a sign-in provider in Firebase Authentication settings before deploying.

Using incorrect Facebook app credentials or not importing them to Firebase.

Firebase needs valid Facebook app ID and secret to authenticate users properly.

Create a Facebook app, get its credentials, and import them correctly into Firebase.

Skipping deployment after changing authentication settings.

Changes only take effect after deployment; otherwise, the app uses old settings.

Run 'firebase deploy --only auth' after any authentication config changes.

Summary

Log in to Firebase CLI to manage your project.

Initialize Firebase Authentication and enable Facebook sign-in.

Deploy authentication settings to apply changes.

Import Facebook app credentials to connect Firebase with Facebook.