Setup

Google Service Account

In order to access a Firebase project using a server SDK, you must authenticate your requests to Firebase with Service Account credentials.

The SDK is able to auto-discover the Service Account for your project in the following conditions:

  1. Your application runs on Google Cloud Engine.

  2. The path to the JSON key file or a JSON string (not recommended) is provided by a GOOGLE_APPLICATION_CREDENTIALS variable.

  3. The JSON Key file is located in Google’s “well known path”

    • on Linux/MacOS: $HOME/.config/gcloud/application_default_credentials.json

    • on Windows: $APPDATA/gcloud/application_default_credentials.json

If auto-discovery is not wanted, you can generate a private key file in JSON format and provide it to the factory directly. To generate a private key file for your service account:

  1. Open https://console.firebase.google.com/project/_/settings/serviceaccounts/adminsdk and select the project you want to generate a private key file for.

  2. Click Generate New Private Key, then confirm by clicking Generate Key

  3. Securely store the JSON file containing the key.

Note

You should store the JSON file outside of your code repository to avoid accidentally exposing it to the outside world.

You can then configure the SDK to use this Service Account:

With the SDK

use Kreait\Firebase\Factory;

$factory = (new Factory)->withServiceAccount('/path/to/firebase_credentials.json');

With the Symfony Bundle

Please see https://github.com/kreait/firebase-bundle#configuration

With the Laravel/Lumen Package

Please see https://github.com/kreait/laravel-firebase#configuration

Project ID

Note

It is not necessary to explicitly configure the project ID in most cases.

Service Account credentials usually include the ID of the Google Cloud Project your Firebase project belongs to.

If you use another type of credential, it might be necessary to provide it manually to the Firebase Factory.

use Kreait\Firebase\Factory;

$factory = (new Factory())
    ->withProjectId('my-project')
    ->withDatabaseUri('https://my-project.firebaseio.com');

You can also set a GOOGLE_CLOUD_PROJECT=<project-id> environment variable before instantiating a component with the factory.

Realtime Database URI

Note

You can find the URI for your Realtime Database at https://console.firebase.google.com/project/_/database. For recently created Firebase projects the default database URI usually has the format https://<project-id>-default-rtdb.firebaseio.com. Databases in projects created before September 2020 had the default database URI https://<project-id>.firebaseio.com.

For backward compatibility reasons, if you don’t specify a database URI, the SDK will use the project ID defined in the Service Account JSON file to automatically generate it.

use Kreait\Firebase\Factory;

$factory = (new Factory())
    ->withDatabaseUri('https://my-project.firebaseio.com');

Caching

Authentication tokens

Before connecting to the Firebase APIs, the SDK fetches an authentication token for your credentials. This authentication token is cached in-memory so that it can be re-used during the same process.

If you want to cache authentication tokens more effectively, you can provide any implementation of psr/cache to the Firebase factory when creating your Firebase instance.

Note

Authentication tokens are cached in-memory by default. For Symfony and Laravel, the Framework’s cache will automatically be used.

For Symfony and Laravel, the Framework’s cache will automatically be used.

Here is an example using the Symfony Cache Component:

use Symfony\Component\Cache\Simple\FilesystemCache;

$factory = $factory->withAuthTokenCache(new FilesystemCache());

ID Token Verification

In order to verify ID tokens, the verifier makes a call to fetch Firebase’s currently available public keys. The keys are cached in memory by default.

If you want to cache the public keys more effectively, you can provide any implementation of psr/simple-cache to the Firebase factory when creating your Firebase instance.

Note

Public keys tokens are cached in-memory by default. For Symfony and Laravel, the Framework’s cache will automatically be used.

Here is an example using the Symfony Cache Component:

use Symfony\Component\Cache\Simple\FilesystemCache;

$factory = $factory->withVerifierCache(new FilesystemCache());

End User Credentials

Note

While theoretically possible, it’s not recommended to use end user credentials in the context of a Server-to-Server backend application.

When using End User Credentials (for example if you set you application default credentials locally with gcloud auth application-default login), you need to provide the ID of the project you want to access directly and suppress warnings triggered by the Google Auth Component:

use Kreait\Firebase\Factory;

putenv('SUPPRESS_GCLOUD_CREDS_WARNING=true');

// This will use the project defined in the Service Account
// credentials files by default
$base = (new Factory())->withProjectId('firebase-project-id');

HTTP Client Options

You can configure the behavior of the Guzzle HTTP Client performing the API requests by passing an instance of Kreait\Firebase\Http\HttpClientOptions to the factory before creating a service.

use Kreait\Firebase\Http\HttpClientOptions;

$options = HttpClientOptions::default();

// Set the maximum amount of seconds (float) that can pass before
// a request is considered timed out
// (default: indefinitely)
$options = $options->withTimeOut(3.5);

// Use a proxy that all API requests should be passed through.
// (default: none)
$options = $options->withProxy('tcp://<host>:<port>');

// Use a custom handler
$options = $options->withGuzzleHandler(...);

$factory = $factory->withHttpClientOptions($options);

// Newly created services will now use the new HTTP options
$realtimeDatabase = $factory->createDatabase();

Setting Guzzle Config Options

In addition to the explicit settings above, you can fully customize the configuration of the Guzzle HTTP Client:

use Kreait\Firebase\Http\HttpClientOptions;

$options = HttpClientOptions::default()
    ->withGuzzleConfigOption('single', 'value')
    ->withGuzzleConfigOptions([
        'first' => 'value',
        'second' => 'value',
    ]);

Note

You can find all Guzzle Config Options at Guzzle: Request Options

Adding Guzzle Middlewares

You can also add middlewares to the Guzzle HTTP Client:

use Kreait\Firebase\Http\HttpClientOptions;

$options = HttpClientOptions::default();

# Adding a single middleware
$options = $options->withGuzzleMiddleware($myMiddleware, 'my_middleware'); // The name can be omitted

# Adding multiple middlewares
$options = $options->withGuzzleMiddlewares([
    # Just providing the middleware
    $myMiddleware,
    # Alternative notation:
    ['middleware' => $myMiddleware]
    # Providing a named middleware
    ['middleware' => $myMiddleware, 'name' => 'my_middleware'],
]);

Note

You can find more information about Guzzle Middlewares at Guzzle: Handlers and Middleware

Logging

In order to log API requests to the Firebase APIs, you can provide the factory with loggers implementing Psr\Log\LoggerInterface.

The following examples use the Monolog logger, but work with any PSR-3 log implementation.

use GuzzleHttp\MessageFormatter;
use Kreait\Firebase\Factory;
use Monolog\Logger;
use Monolog\Handler\StreamHandler;

$httpLogger = new Logger('firebase_http_logs');
$httpLogger->pushHandler(new StreamHandler('path/to/firebase_api.log', Logger::INFO));

// Without further arguments, requests and responses will be logged with basic
// request and response information. Successful responses will be logged with
// the 'info' log level, failures (Status code >= 400) with 'notice'
$factory = $factory->withHttpLogger($httpLogger);

// You can configure the message format and log levels individually
$messageFormatter = new MessageFormatter(MessageFormatter::SHORT);
$factory = $factory->withHttpLogger(
    $httpLogger, $messageFormatter, $successes = 'debug', $errors = 'warning'
);

// You can provide a separate logger for detailed HTTP message logs
$httpDebugLogger = new Logger('firebase_http_debug_logs');
$httpDebugLogger->pushHandler(
    new StreamHandler('path/to/firebase_api_debug.log',
    Logger::DEBUG)
);

// Logs will include the full request and response headers and bodies
$factory = $factory->withHttpDebugLogger($httpDebugLogger)