Laravel Firebase Authentication

A production-ready Firebase Authentication driver for Laravel that enables seamless JWT-based authentication using Firebase tokens.

Table of Contents

• Features
• Requirements
• Installation
• Quick Start
• Configuration
  • Standard Setup (with Database)
  • Microservice Setup (without Database)
  • Web Guard Configuration
• Usage
  • Basic Authentication
  • Anonymous Users
  • Accessing JWT Claims
  • Working with Firebase Tokens
• API Reference
• Common Use Cases
• Security Considerations
• Troubleshooting
• Contributing
• License

Features

• JWT Token Verification: Securely verify Firebase Authentication JWT tokens
• Automatic User Sync: Automatically create/update users from Firebase claims
• Anonymous Authentication: Built-in support for Firebase anonymous users
• Microservice Ready: Stateless authentication without database dependency
• Web & API Guards: Support for both session-based and API authentication
• Token Caching: Optimized token verification with built-in caching
• Laravel Integration: Native integration with Laravel's authentication system
• Flexible User Models: Works with Eloquent, or custom models

Requirements

• PHP 8.0 or higher
• Laravel 9.x, 10.x, 11.x, 12.x
• Firebase project with Authentication enabled

Installation

Install the package via Composer:

composer require firevel/firebase-authentication

The package will automatically register its service provider.

Quick Start

For a quick setup with API authentication:

1. Set your Firebase project ID in .env:

GOOGLE_CLOUD_PROJECT=your-firebase-project-id

2. Configure auth guard in config/auth.php:

'guards' => [
    'api' => [
        'driver' => 'firebase',
        'provider' => 'users',
    ],
],

3. Add trait to your User model:

use Firevel\FirebaseAuthentication\FirebaseAuthenticable;

class User extends Authenticatable
{
    use FirebaseAuthenticable;

    public $incrementing = false;
    protected $fillable = ['name', 'email', 'picture'];

    // Optional: Customize how users are matched (default: ['sub' => 'id'])
    protected $firebaseResolveBy = 'email'; // use 'email' to automatically create or find user by email

    // Optional: Customize which Firebase claims map to which user attributes
    protected $firebaseClaimsMapping = [
        'email' => 'email',
        'name' => 'name',
    ];
}

4. Protect your routes:

Route::middleware('auth:api')->get('/user', function (Request $request) {
    return $request->user();
});

That's it! Send requests with Authorization: Bearer {firebase-jwt-token} header.

Configuration

Standard Setup (with Database)

This setup stores user data in your database and syncs it with Firebase claims.

1. Environment Configuration

Add your Firebase project ID to .env:

GOOGLE_CLOUD_PROJECT=your-firebase-project-id

Alternatively, publish and configure the firebase config:

// config/firebase.php
return [
    'project_id' => env('FIREBASE_PROJECT_ID', 'your-project-id'),
];

2. Update Authentication Configuration

Modify config/auth.php to use the Firebase driver:

'guards' => [
    'web' => [
        'driver' => 'firebase',
        'provider' => 'users',
    ],

    'api' => [
        'driver' => 'firebase',
        'provider' => 'users',
    ],
],

3. Update Your User Model

Add the FirebaseAuthenticable trait to your User model:

Eloquent Example:

<?php

namespace App\Models;

use Firevel\FirebaseAuthentication\FirebaseAuthenticable;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;

class User extends Authenticatable
{
    use Notifiable, FirebaseAuthenticable;

    /**
     * Indicates if the IDs are auto-incrementing.
     *
     * @var bool
     */
    public $incrementing = false;

    /**
     * The "type" of the primary key ID.
     *
     * @var string
     */
    protected $keyType = 'string';

    /**
     * The attributes that are mass assignable.
     *
     * @var array<string>
     */
    protected $fillable = [
        'name',
        'email',
        'picture',
    ];

}

4. Create/Update Users Table Migration

If using a SQL database, create a migration for the users table:

php artisan make:migration create_users_table

public function up()
{
    Schema::create('users', function (Blueprint $table) {
        $table->string('id')->primary(); // Firebase UID
        $table->string('name')->nullable();
        $table->string('email')->unique()->nullable();
        $table->string('picture')->nullable();
        $table->timestamps();
    });
}

Run the migration:

php artisan migrate

Microservice Setup (without Database)

For microservices that only need to verify authentication without storing user data, use the FirebaseIdentity model.

1. Update Authentication Configuration

In config/auth.php, configure only the API guard:

'guards' => [
    'api' => [
        'driver' => 'firebase',
        'provider' => 'users',
    ],
],

'providers' => [
    'users' => [
        'driver' => 'eloquent',
        'model' => Firevel\FirebaseAuthentication\FirebaseIdentity::class,
    ],
],

Laravel 11+ Alternative:

Use the AUTH_MODEL environment variable:

GOOGLE_CLOUD_PROJECT=your-firebase-project-id
AUTH_MODEL=Firevel\FirebaseAuthentication\FirebaseIdentity

2. Protect Your Routes

Route::middleware('auth:api')->group(function () {
    Route::get('/data', [DataController::class, 'index']);
    Route::post('/process', [ProcessController::class, 'handle']);
});

Benefits:

• No database connection required for authentication
• Lightweight and fast
• Perfect for serverless deployments
• User data available from JWT claims

Web Guard Configuration

To use Firebase authentication with web routes (session-based), you need to extract the bearer token from cookies.

Add Middleware

In bootstrap/app.php (Laravel 11+):

->withMiddleware(function (Middleware $middleware) {
    $middleware->web(append: [
        \Firevel\FirebaseAuthentication\Http\Middleware\AddAccessTokenFromCookie::class,
    ]);
})

Or in app/Http/Kernel.php (Laravel 10 and below):

protected $middlewareGroups = [
    'web' => [
        // ... other middleware
        \Firevel\FirebaseAuthentication\Http\Middleware\AddAccessTokenFromCookie::class,
    ],
];

The middleware reads the raw cookie value directly, so no encryption exclusion configuration is required.

Usage

Basic Authentication

In Controllers:

use Illuminate\Http\Request;

class ProfileController extends Controller
{
    public function show(Request $request)
    {
        $user = $request->user();

        return response()->json([
            'id' => $user->id,
            'name' => $user->name,
            'email' => $user->email,
        ]);
    }
}

In Routes:

Route::middleware('auth:api')->get('/profile', function (Request $request) {
    return $request->user();
});

Manual Authentication Check:

if (auth()->check()) {
    $userId = auth()->id();
    $user = auth()->user();
}

Anonymous Users

Firebase supports anonymous authentication, allowing users to access your app without signing up.

Check if User is Anonymous:

$user = auth()->user();

if ($user->isAnonymous()) {
    return response()->json([
        'message' => 'Limited features available. Sign up for full access!',
        'features' => ['read-only'],
    ]);
}

// Regular authenticated user
return response()->json([
    'message' => 'Welcome back!',
    'features' => ['read', 'write', 'share'],
]);

Conditional Logic Based on Authentication Type:

class PostController extends Controller
{
    public function store(Request $request)
    {
        $user = $request->user();

        if ($user->isAnonymous()) {
            return response()->json([
                'error' => 'Anonymous users cannot create posts',
            ], 403);
        }

        // Create post for authenticated user
        $post = Post::create([
            'user_id' => $user->id,
            'title' => $request->title,
            'content' => $request->content,
        ]);

        return response()->json($post, 201);
    }
}

Frontend Example:

// Sign in anonymously
const userCredential = await firebase.auth().signInAnonymously();
const token = await userCredential.user.getIdToken();

// Make API request
const response = await fetch('/api/posts', {
    headers: {
        'Authorization': `Bearer ${token}`,
    },
});

Accessing JWT Claims

All JWT token claims are available through the user model:

$user = auth()->user();

// Get all claims
$claims = $user->getClaims();

// Access specific claim data
$firebase = $claims['firebase'] ?? [];
$signInProvider = $firebase['sign_in_provider'] ?? null; // 'google.com', 'password', 'anonymous', etc.
$identities = $firebase['identities'] ?? [];

// Check authentication method
if ($signInProvider === 'google.com') {
    // User signed in with Google
} elseif ($signInProvider === 'password') {
    // User signed in with email/password
}

// Access custom claims (set in Firebase Admin SDK)
$customClaims = $claims['custom_claim_name'] ?? null;

Example with Custom Claims:

// Assuming you set custom claims in Firebase:
// admin.auth().setCustomUserClaims(uid, { role: 'admin', subscriptionTier: 'premium' })

$user = auth()->user();
$claims = $user->getClaims();

$role = $claims['role'] ?? 'user';
$tier = $claims['subscriptionTier'] ?? 'free';

if ($role === 'admin') {
    // Grant admin access
}

if ($tier === 'premium') {
    // Enable premium features
}

Working with Firebase Tokens

Get the Raw JWT Token:

$user = auth()->user();
$token = $user->getFirebaseAuthenticationToken();

// Use token for Firebase Admin SDK operations
// or pass to frontend for Firebase Realtime Database/Firestore authentication

Validate Token Expiration:

The package automatically handles token expiration. Expired tokens return null for auth()->user().

$user = auth()->user();

if (!$user) {
    return response()->json(['error' => 'Unauthorized or token expired'], 401);
}

API Reference

FirebaseAuthenticable Trait

Methods available on User models using the FirebaseAuthenticable trait:

resolveByClaims(array $claims): object

Resolves or creates a user from JWT token claims.

$user = (new User)->resolveByClaims($claims);

setClaims(array $claims): self

Stores JWT claims on the user instance.

$user->setClaims($claims);

getClaims(): array

Retrieves all JWT token claims.

$claims = $user->getClaims();

isAnonymous(): bool

Checks if the user authenticated anonymously.

if ($user->isAnonymous()) {
    // Handle anonymous user
}

setFirebaseAuthenticationToken(string $token): self

Stores the raw JWT token.

$user->setFirebaseAuthenticationToken($token);

getFirebaseAuthenticationToken(): ?string

Retrieves the raw JWT token.

$token = $user->getFirebaseAuthenticationToken();

$firebaseResolveBy Property

Controls which attribute is used to match existing users in your database. This determines how the package looks up users when authenticating.

// Default: Match by Firebase UID (sub claim) to id column
protected $firebaseResolveBy = ['sub' => 'id'];

// Match by email (when claim name = model attribute)
protected $firebaseResolveBy = 'email';

// Match by Firebase UID to custom column
protected $firebaseResolveBy = ['sub' => 'firebase_uid'];

Default behavior: ['sub' => 'id'] - matches Firebase UID (sub claim) to the id column

Formats:

• Array format ['claim_key' => 'model_attribute'] - Use when claim name differs from model attribute (e.g., ['sub' => 'firebase_uid'])
• String format 'attribute_name' - Use when claim and model attribute have the same name (e.g., 'email')

$firebaseClaimsMapping Property

Controls how Firebase JWT claims are mapped to user model attributes. Define this property in your User model to customize the mapping:

protected $firebaseClaimsMapping = [
    'email' => 'email',          // Model attribute => JWT claim key
    'name' => 'name',
    'picture' => 'picture',
    'phone' => 'phone_number',   // Map phone_number claim to phone attribute
];

Default mapping:

• email → email
• name → name
• picture → picture

transformClaims(array $claims): array

Transforms JWT claims into user attributes using the $firebaseClaimsMapping property. Override this method for advanced customization beyond simple mapping:

public function transformClaims(array $claims): array
{
    // Start with the standard mapping
    $attributes = parent::transformClaims($claims);

    // Add conditional logic or data transformation
    if (!empty($claims['email_verified'])) {
        $attributes['email_verified_at'] = $claims['email_verified']
            ? now()
            : null;
    }

    return $attributes;
}

FirebaseGuard

The guard is automatically registered and handles authentication. You typically don't interact with it directly, but use Laravel's auth() helper.

Common Use Cases

Matching Users by Email Instead of Firebase UID

If you have an existing user database and want to match Firebase users by email instead of Firebase UID:

// App/Models/User.php
class User extends Authenticatable
{
    use FirebaseAuthenticable;

    // Match users by email instead of Firebase UID
    protected $firebaseResolveBy = 'email';

    // Auto-incrementing integer ID
    public $incrementing = true;
    protected $keyType = 'int';

    protected $fillable = [
        'name',
        'email',
        'picture',
    ];

    protected $firebaseClaimsMapping = [
        'email' => 'email',
        'name' => 'name',
        'picture' => 'picture',
    ];
}

Migration:

Schema::create('users', function (Blueprint $table) {
    $table->id(); // Auto-incrementing integer ID
    $table->string('email')->unique();
    $table->string('name')->nullable();
    $table->string('picture')->nullable();
    $table->timestamps();
});

Use case: When migrating from a traditional authentication system to Firebase, this allows you to keep your existing user IDs and match by email.

Using Custom Firebase UID Column

If you want to store Firebase UID in a separate column while keeping an auto-incrementing primary key:

// App/Models/User.php
class User extends Authenticatable
{
    use FirebaseAuthenticable;

    // Match Firebase UID (sub claim) to firebase_uid column
    protected $firebaseResolveBy = ['sub' => 'firebase_uid'];

    public $incrementing = true;
    protected $keyType = 'int';

    protected $fillable = [
        'firebase_uid',
        'name',
        'email',
        'picture',
    ];
}

Migration:

Schema::create('users', function (Blueprint $table) {
    $table->id();
    $table->string('firebase_uid')->unique();
    $table->string('email')->unique()->nullable();
    $table->string('name')->nullable();
    $table->string('picture')->nullable();
    $table->timestamps();

    $table->index('firebase_uid'); // Index for faster lookups
});

Role-Based Access Control with Custom Claims

// Middleware: app/Http/Middleware/RequireRole.php
class RequireRole
{
    public function handle(Request $request, Closure $next, string $role)
    {
        $user = $request->user();

        if (!$user) {
            return response()->json(['error' => 'Unauthorized'], 401);
        }

        $claims = $user->getClaims();
        $userRole = $claims['role'] ?? 'user';

        if ($userRole !== $role) {
            return response()->json(['error' => 'Forbidden'], 403);
        }

        return $next($request);
    }
}

// Route usage
Route::middleware(['auth:api', 'role:admin'])->group(function () {
    Route::get('/admin/users', [AdminController::class, 'users']);
});

Syncing Additional User Data

Simple Mapping (Recommended):

Use the $firebaseClaimsMapping property for straightforward claim-to-attribute mapping:

// App/Models/User.php
class User extends Authenticatable
{
    use FirebaseAuthenticable;

    protected $firebaseClaimsMapping = [
        'email' => 'email',
        'name' => 'name',
        'picture' => 'picture',
        'phone' => 'phone_number',    // Map phone_number claim to phone
        'locale' => 'locale',          // Map locale claim to locale
    ];

    protected $fillable = [
        'name',
        'email',
        'picture',
        'phone',
        'locale',
    ];
}

Advanced Mapping with Transformation Logic:

Override transformClaims() when you need conditional logic or data transformation:

// App/Models/User.php
public function transformClaims(array $claims): array
{
    // Start with the standard mapping from $firebaseClaimsMapping
    $attributes = parent::transformClaims($claims);

    // Add conditional transformations
    if (!empty($claims['email_verified'])) {
        $attributes['email_verified_at'] = $claims['email_verified']
            ? now()
            : null;
    }

    // Transform data format
    if (!empty($claims['metadata']['creationTime'])) {
        $attributes['firebase_created_at'] = Carbon::parse($claims['metadata']['creationTime']);
    }

    return $attributes;
}

Multi-Tenancy with Firebase

// Set tenant ID as custom claim in Firebase
// admin.auth().setCustomUserClaims(uid, { tenantId: 'tenant-123' })

class TenantMiddleware
{
    public function handle(Request $request, Closure $next)
    {
        $user = $request->user();
        $claims = $user->getClaims();

        $tenantId = $claims['tenantId'] ?? null;

        if (!$tenantId) {
            return response()->json(['error' => 'No tenant assigned'], 403);
        }

        // Set tenant for current request
        app()->instance('current_tenant', $tenantId);

        return $next($request);
    }
}

Security Considerations

Token Verification

• All tokens are verified using Firebase's official JWT verification library
• Token signatures are validated against Firebase's public keys
• Token expiration is automatically enforced
• Tokens are cached to improve performance

Best Practices

1. Always use HTTPS in production to prevent token interception
2. Implement token refresh on the frontend before expiration (tokens expire after 1 hour)
3. Never log tokens in production environments
4. Use custom claims for roles/permissions instead of storing in database
5. Validate user input even for authenticated requests
6. Rate limit authentication endpoints to prevent abuse

CORS Configuration

When using API authentication, configure CORS properly:

// config/cors.php
return [
    'paths' => ['api/*'],
    'allowed_methods' => ['*'],
    'allowed_origins' => [env('FRONTEND_URL', 'http://localhost:3000')],
    'allowed_headers' => ['*'],
    'exposed_headers' => [],
    'max_age' => 0,
    'supports_credentials' => true,
];

Environment Variables

Never commit sensitive credentials. Use .env:

GOOGLE_CLOUD_PROJECT=your-project-id
APP_ENV=production
APP_DEBUG=false

Troubleshooting

"No users provider found"

Problem: Laravel can't find the users provider.

Solution: Ensure config/auth.php has the provider configured:

'providers' => [
    'users' => [
        'driver' => 'eloquent',
        'model' => App\Models\User::class,
    ],
],

"Token verification failed"

Problem: JWT token can't be verified.

Common causes:

• Wrong GOOGLE_CLOUD_PROJECT environment variable
• Token expired (tokens are valid for 1 hour)
• Token from wrong Firebase project
• System clock skew

Solution:

1. Verify your Firebase project ID matches the token issuer
2. Check token expiration on frontend and refresh if needed
3. Ensure server time is synchronized (NTP)

"Class 'IdTokenVerifier' not found"

Problem: Missing dependencies.

Solution:

composer require kreait/firebase-tokens symfony/cache

Users not being created/updated

Problem: User model not syncing with Firebase claims.

Solution:

1. Verify FirebaseAuthenticable trait is added to User model
2. Check $fillable includes: ['name', 'email', 'picture']
3. Ensure $incrementing = false is set
4. Verify database migration has id as string column

"No password support for Firebase Users"

Problem: Trying to use password-based authentication methods.

Expected behavior: Firebase JWT authentication doesn't use passwords. This is correct.

Solution: Use Firebase Authentication on the frontend to obtain JWT tokens.

Web guard not working

Problem: Authentication works for API but not web routes.

Solution:

1. Ensure AddAccessTokenFromCookie middleware is added to web middleware group
2. Check that frontend is setting the cookie correctly
3. Verify cookie domain matches your application domain

Anonymous users can't be identified

Problem: isAnonymous() returns false for anonymous users.

Solution: Ensure you're using the latest version of the package. The anonymous detection was added recently. Update with:

composer update firevel/firebase-authentication

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Guidelines

• Follow PSR-12 coding standards
• Add tests for new features
• Update documentation for API changes
• Keep backwards compatibility when possible

License

This package is open-sourced software licensed under the MIT license.

Support

• Issues: GitHub Issues
• Documentation: Firebase Authentication Docs
• Laravel Docs: Authentication