Cloud Messaging

You can use the Firebase Admin SDK for PHP to send Firebase Cloud Messaging messages to end-user devices. Specifically, you can send messages to individual devices, named topics, or condition statements that match one or more topics.

Note

Sending messages to Device Groups is only possible with legacy protocols which are not supported by this SDK.

Before you start, please read about Firebase Cloud Messaging in the official documentation:

Initializing the Messaging component

With the SDK

$messaging = $factory->createMessaging();

With Dependency Injection (Symfony Bundle/Laravel/Lumen Package)

use Kreait\Firebase\Contract\Messaging;

class MyService
{
    public function __construct(Messaging $messaging)
    {
        $this->messaging = $messaging;
    }
}

With the Laravel app() helper (Laravel/Lumen Package)

$messaging = app('firebase.messaging');

Getting started

use Kreait\Firebase\Messaging\CloudMessage;

$message = CloudMessage::new()
    ->withNotification(Notification::create('Title', 'Body'))
    ->withData(['key' => 'value'])
    ->toToken('...')
    // ->toTopic('...')
    // ->toCondition('...')
;

$messaging->send($message);

A message must be an object implementing Kreait\Firebase\Messaging\Message or an array that can be parsed to a Kreait\Firebase\Messaging\CloudMessage.

You can use Kreait\Firebase\Messaging\RawMessageFromArray to create a message without the SDK checking it for validity before sending it. This gives you full control over the sent message, but also means that you have to send/validate a message in order to know if it’s valid or not.

Note

If you notice that a field is not supported by the SDK yet, please open an issue on the issue tracker, so that others can benefit from it as well.

Send messages to topics

Based on the publish/subscribe model, FCM topic messaging allows you to send a message to multiple devices that have opted in to a particular topic. You compose topic messages as needed, and FCM handles routing and delivering the message reliably to the right devices.

For example, users of a local weather forecasting app could opt in to a “severe weather alerts” topic and receive notifications of storms threatening specified areas. Users of a sports app could subscribe to automatic updates in live game scores for their favorite teams.

Some things to keep in mind about topics:

  • Topic messaging supports unlimited topics and subscriptions for each app.

  • Topic messaging is best suited for content such as news, weather, or other publicly available information.

  • Topic messages are optimized for throughput rather than latency. For fast, secure delivery to single devices or small groups of devices, target messages to registration tokens, not topics.

You can create a message to a topic in one of the following ways:

use Kreait\Firebase\Exception\MessagingException;
use Kreait\Firebase\Messaging\CloudMessage;

$topic = 'a-topic';

$message = CloudMessage::new()
    ->withNotification($notification) // optional
    ->withData($data) // optional
    ->toTopic($topic)
;

$message = CloudMessage::fromArray([
    'topic' => $topic,
    'notification' => [/* Notification data as array */], // optional
    'data' => [/* data array */], // optional
]);

try {
    $result = $messaging->send($message);
    // $result = ['name' => 'projects/<project-id>/messages/6810356097230477954']
} catch (MessagingException $e) {
    // ...
}

Send conditional messages

Warning

OR-conditions are currently not processed correctly by the Firebase Rest API, leading to undelivered messages. This can be resolved by splitting up a message to an OR-condition into multiple messages to AND-conditions. So one conditional message to 'a' in topics || 'b' in topics should be sent as two messages to the conditions 'a' in topics && !('b' in topics) and 'b' in topics && !('a' in topics)

References:

Sometimes you want to send a message to a combination of topics. This is done by specifying a condition, which is a boolean expression that specifies the target topics. For example, the following condition will send messages to devices that are subscribed to TopicA and either TopicB or TopicC:

"'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)"

FCM first evaluates any conditions in parentheses, and then evaluates the expression from left to right. In the above expression, a user subscribed to any single topic does not receive the message. Likewise, a user who does not subscribe to TopicA does not receive the message. These combinations do receive it:

  • TopicA and TopicB

  • TopicA and TopicC

use Kreait\Firebase\Messaging\CloudMessage;

$condition = "'TopicA' in topics && ('TopicB' in topics || 'TopicC' in topics)";

$message = CloudMessage::new()
    ->withNotification($notification) // optional
    ->withData($data) // optional
    ->toCondition($condition)
;

$message = CloudMessage::fromArray([
    'condition' => $condition,
    'notification' => [/* Notification data as array */], // optional
    'data' => [/* data array */], // optional
]);

$messaging->send($message);

Send messages to specific devices

The Admin FCM API allows you to send messages to individual devices by specifying a registration token for the target device. Registration tokens are strings generated by the client FCM SDKs for each end-user client app instance.

Each of the Firebase client SDKs are able to generate these registration tokens: iOS, Android, Web, C++, and Unity.

use Kreait\Firebase\Messaging\CloudMessage;

$deviceToken = '...';

$message = CloudMessage::new()
    ->withNotification($notification) // optional
    ->withData($data) // optional
    ->toToken($deviceToken)
;

$message = CloudMessage::fromArray([
    'token' => $deviceToken,
    'notification' => [/* Notification data as array */], // optional
    'data' => [/* data array */], // optional
]);

$result = $messaging->send($message);
// $result = ['name' => 'projects/<project-id>/messages/<message-id>']

Send messages in batches

Note

If you need to send a message to more than a few devices, consider sending the message to a topic instead.

use Kreait\Firebase\Messaging\CloudMessage;

$messages = [
    // Either objects implementing Kreait\Firebase\Messaging\Message or arrays that can
    // be parsed into to Kreait\Firebase\Messaging\CloudMessage objects
];

/** @var Kreait\Firebase\Messaging\MulticastSendReport $sendReport **/
$sendReport = $messaging->sendAll($messages);

The sendMulticast() message is a convenience method to send one message to multiple devices.

use Kreait\Firebase\Messaging\CloudMessage;

$message = CloudMessage::new(); // Any instance of Kreait\Messaging\Message
$deviceTokens = ['...', '...' /* ... */];

/** @var Kreait\Firebase\Messaging\MulticastSendReport $sendReport **/
$sendReport = $messaging->sendMulticast($message, $deviceTokens);

The returned value $sendReport is an instance of Kreait\Firebase\Messaging\MulticastSendReport and provides you with methods to determine the successes and failures of the multicasted message:

$report = $messaging->sendMulticast($message, $deviceTokens);

echo 'Successful sends: '.$report->successes()->count().PHP_EOL;
echo 'Failed sends: '.$report->failures()->count().PHP_EOL;

if ($report->hasFailures()) {
    foreach ($report->failures()->getItems() as $failure) {
        echo $failure->error()->getMessage().PHP_EOL;
    }
}

// The following methods return arrays with registration token strings
$successfulTargets = $report->validTokens(); // string[]

// Unknown tokens are tokens that are valid but not know to the currently
// used Firebase project. This can, for example, happen when you are
// sending from a project on a staging environment to tokens in a
// production environment
$unknownTargets = $report->unknownTokens(); // string[]

// Invalid (=malformed) tokens
$invalidTargets = $report->invalidTokens(); // string[]

Note

The sendMulticast method stems from a time where Firebase had a (now shutdown) dedicated API endpoint for multicast messages. It is now a wrapper for the sendAll() method. “Legacy” is also the reason why the returned report is named MulticastSendReport.

Adding a notification

A notification is an instance of Kreait\Firebase\Messaging\Notification and can be created in one of the following ways. The title and the body of a notification are both optional.

use Kreait\Firebase\Messaging\Notification;

$title = 'My Notification Title';
$body = 'My Notification Body';
$imageUrl = 'https://picsum.photos/400/200';

$notification = Notification::fromArray([
    'title' => $title,
    'body' => $body,
    'image' => $imageUrl,
]);

$notification = Notification::create($title, $body);

$changedNotification = $notification
    ->withTitle('Changed title')
    ->withBody('Changed body')
    ->withImageUrl('https://picsum.photos/200/400');

Once you have created a message with one of the methods described below, you can attach the notification to it:

$message = $message->withNotification($notification);

Adding data

The data attached to a message must be an array of key-value pairs where all keys and values are strings.

Once you have created a message with one of the methods described below, you can attach data to it:

$data = [
    'first_key' => 'First Value',
    'second_key' => 'Second Value',
];

$message = $message->withData($data);

Adding target platform specific configuration

You can target platforms specific configuration to your messages.

Android

You can find the full Android configuration reference in the official documentation: REST Resource: projects.messages.AndroidConfig

use Kreait\Firebase\Messaging\AndroidConfig;

// Example from https://firebase.google.com/docs/cloud-messaging/admin/send-messages#android_specific_fields
$config = AndroidConfig::fromArray([
    'ttl' => '3600s',
    'priority' => 'normal',
    'notification' => [
        'title' => '$GOOG up 1.43% on the day',
        'body' => '$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.',
        'icon' => 'stock_ticker_update',
        'color' => '#f45342',
        'sound' => 'default',
    ],
]);

$message = $message->withAndroidConfig($config);

APNs

You can find the full APNs configuration reference in the official documentation: REST Resource: projects.messages.ApnsConfig

use Kreait\Firebase\Messaging\ApnsConfig;

// Example from https://firebase.google.com/docs/cloud-messaging/admin/send-messages#apns_specific_fields
$config = ApnsConfig::fromArray([
    'headers' => [
        'apns-priority' => '10',
    ],
    'payload' => [
        'aps' => [
            'alert' => [
                'title' => '$GOOG up 1.43% on the day',
                'body' => '$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.',
            ],
            'badge' => 42,
            'sound' => 'default',
        ],
    ],
]);

$message = $message->withApnsConfig($config);

WebPush

You can find the full WebPush configuration reference in the official documentation: REST Resource: projects.messages.Webpush

use Kreait\Firebase\Messaging\WebPushConfig;

// Example from https://firebase.google.com/docs/cloud-messaging/admin/send-messages#webpush_specific_fields
$config = WebPushConfig::fromArray([
    'notification' => [
        'title' => '$GOOG up 1.43% on the day',
        'body' => '$GOOG gained 11.80 points to close at 835.67, up 1.43% on the day.',
        'icon' => 'https://my-server.example/icon.png',
    ],
    'fcm_options' => [
        'link' => 'https://my-server.example/some-page',
    ],
]);

$message = $message->withWebPushConfig($config);

Adding platform independent FCM options

You can find the full FCM Options configuration reference in the official documentation: REST Resource: projects.messages.fcm_options

use Kreait\Firebase\Messaging\FcmOptions;

$fcmOptions = FcmOptions::create()
    ->withAnalyticsLabel('my-analytics-label');
// or
$fcmOptions = [
    'analytics_label' => 'my-analytics-label'
];

$message = $message->withFcmOptions($fcmOptions);

Notification Sounds

The SDK provides helper methods to add sounds to messages:

  • CloudMessage::withDefaultSounds()

  • AndroidConfig::withDefaultSound()

  • AndroidConfig::withSound($sound)

  • ApnsConfig::withDefaultSound()

  • ApnsConfig::withSound($sound)

Note

WebPush notification don’t support the inclusion of sounds.

$message = CloudMessage::new()
    ->withNotification(['title' => 'Notification title', 'body' => 'Notification body'])
    ->withDefaultSounds() // Enables default notifications sounds on iOS and Android devices.
    ->withApnsConfig(
        ApnsConfig::new()
            ->withSound('bingbong.aiff')
            ->withBadge(1)
    )
;

Message Priority

The SDK provides helper methods to define the priority of a message.

Note

You can learn more about message priorities for the different target platforms at Setting the priority of a message in the official Firebase documentation.

Note

Setting a message priority is optional. If you don’t set a priority, the Firebase backend or the target platform uses their defined defaults.

Android

  • AndroidConfig::withNormalPriority()

  • AndroidConfig::withHighPriority()

  • AndroidConfig::withPriority(string $priority)

iOS (APNS)

  • ApnsConfig::withPowerConservingPriority()

  • ApnsConfig::withImmediatePriority()

  • ApnsConfig::withPriority(string $priority)

Web

  • WebPushConfig::withVeryLowUrgency()

  • WebPushConfig::withLowUrgency()

  • WebPushConfig::withNormalUrgency()

  • WebPushConfig::withHighUrgency()

  • WebPushConfig::withUrgency(string $urgency)

Combined

  • CloudMessage::withLowestPossiblePriority()

  • CloudMessage::withHighestPossiblePriority()

Example

$message = CloudMessage::new()
    ->withNotification([
        'title' => 'If you had an iOS device…',
        'body' => '… you would have received a very important message'
    ])
    ->withLowestPossiblePriority()
    ->withApnsConfig(
        ApnsConfig::new()
            ->withImmediatePriority()
            ->withNotification([
                'title => 'A very important message…',
                'body' => ' that requires your immediate attention.'
            ])
    )
;

Using Emojis

Firebase Messaging supports Emojis in Messages.

Note

You can find a full list of all currently available Emojis at https://www.unicode.org/emoji/charts/full-emoji-list.html

// You can copy and paste an emoji directly into you source code
$text = "This is an emoji 😀";
$text = "This is an emoji \u{1F600}";

Sending a raw/custom messages

Instead of composing messages with the help of the CloudMessage builder, you can use RawMessageFromArray as a wrapper for a pre-compiled message payload. Alternatively, you can implement custom messages by implementing the Kreait\Firebase\Messaging\Message interface.

use Kreait\Firebase\Messaging\RawMessageFromArray;

$message = new RawMessageFromArray([
        'notification' => [
            // https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#notification
            'title' => 'Default title',
            'body' => 'Default body',
        ],
        'data' => [
            'key' => 'Value',
        ],
        'android' => [
            // https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#androidconfig
            'notification' => [
                'title' => 'Android Title',
                'body' => 'Android Body',
            ],
        ],
        'apns' => [
            // https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#apnsconfig
            'payload' => [
                'aps' => [
                    'alert' => [
                        'title' => 'iOS Title',
                        'body' => 'iOS Body',
                    ],
                ],
            ],
        ],
        'webpush' => [
            // https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#webpushconfig
            'notification' => [
                'title' => 'Webpush Title',
                'body' => 'Webpush Body'
            ],
        ],
        'fcm_options' => [
            // https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#fcmoptions
            'analytics_label' => 'some-analytics-label'
        ]
    ]);

$messaging->send($message);

Validating messages

You can validate a message by sending a validation-only request to the Firebase REST API. If the message is invalid, a Kreait\Firebase\Exception\Messaging\InvalidMessage exception is thrown, which you can catch to evaluate the raw error message(s) that the API returned.

use Kreait\Firebase\Exception\Messaging\InvalidMessage;

try {
    $messaging->validate($message);
    // or
    $messaging->send($message, $validateOnly = true);
} catch (InvalidMessage $e) {
    print_r($e->errors());
}

You can also use the send* methods with an additional parameter:

$validateOnly = true;

$messaging->send($message, $validateOnly);
$messaging->sendMulticast($message, $tokens, $validateOnly);
$messaging->sendAll($messages, $validateOnly);

Validating Registration Tokens

If you have a set of registration tokens that you want to check for validity or if they are still registered to your project, you can use the validateTokens() method:

$tokens = [...];

$result = $messaging->validateRegistrationTokens($tokens);

The result is an array with three keys containing the checked tokens:

  • valid contains all tokens that are valid and registered to the current Firebase project

  • unknown contains all tokens that are valid, but not registered to the current Firebase project

  • invalid contains all invalid (=malformed) tokens

Topic management

You can subscribe one or multiple devices to one or multiple messaging topics with the following methods:

$result = $messaging->subscribeToTopic($topic, $registrationTokenOrTokens);
$result = $messaging->subscribeToTopics($topics, $registrationTokenOrTokens);

$result = $messaging->unsubscribeFromTopic($topic, $registrationTokenOrTokens);
$result = $messaging->unsubscribeFromTopics($topics, $registrationTokenOrTokens);

$result = $messaging->unsubscribeFromAllTopics($registrationTokenOrTokens);

The result will return an array in which the keys are the topic names, and the values are the operation results for the individual tokens.

Note

You can subscribe up to 1,000 devices in a single request. If you provide an array with over 1,000 registration tokens, the operation will fail with an error.

App instance management

A registration token is related to an application that generated it. You can retrieve current information about an app instance by passing a registration token to the getAppInstance() method.

$registrationToken = '...';

$appInstance = $messaging->getAppInstance($registrationToken);
// Return the full information as provided by the Firebase API
$instanceInfo = $appInstance->rawData();

/* Example output for an Android application instance:
    [
      "applicationVersion" => "1060100"
      "connectDate" => "2019-07-21"
      "attestStatus" => "UNKNOWN"
      "application" => "com.vendor.application"
      "scope" => "*"
      "authorizedEntity" => "..."
      "rel" => array:1 [
        "topics" => array:3 [
          "test-topic" => array:1 [
            "addDate" => "2019-07-21"
          ]
          "test-topic-5d35b46a15094" => array:1 [
            "addDate" => "2019-07-22"
          ]
          "test-topic-5d35b46b66c31" => array:1 [
            "addDate" => "2019-07-22"
          ]
        ]
      ]
      "connectionType" => "WIFI"
      "appSigner" => "..."
      "platform" => "ANDROID"
    ]
*/

/* Example output for a web application instance
    [
      "application" => "webpush"
      "scope" => ""
      "authorizedEntity" => "..."
      "rel" => array:1 [
        "topics" => array:2 [
          "test-topic-5d35b445b830a" => array:1 [
            "addDate" => "2019-07-22"
          ]
          "test-topic-5d35b446c0839" => array:1 [
            "addDate" => "2019-07-22"
          ]
        ]
      ]
      "platform" => "BROWSER"
    ]
*/

Note

As the data returned by the Google Instance ID API can return differently formed results depending on the application or platform, it is currently difficult to add reliable convenience methods for specific fields in the raw data.

Working with topic subscriptions

You can retrieve all topic subscriptions for an app instance with the topicSubscriptions() method:

$appInstance = $messaging->getAppInstance('<registration token>');

/** @var \Kreait\Firebase\Messaging\TopicSubscriptions $subscriptions */
$subscriptions = $appInstance->topicSubscriptions();

foreach ($subscriptions as $subscription) {
    echo "{$subscription->registrationToken()} is subscribed to {$subscription->topic()}\n";
}

Error Handling

Errors returned by the Firebase FCM API are converted to exceptions implementing the Kreait\Firebase\Exception\MessagingException. Each implementation of this interface has an errors() method that provides additional information about the error.

use Kreait\Firebase\Exception\MessagingException;

try {
    $messaging->send($message);
} catch (MessagingException $e) {
    echo $e->getMessage();
    print_r($e->errors());
}

Malformatted messages

Messages built with the CloudMessage builder should be automatically valid, but if you implement your own Kreait\Firebase\Messaging\Message implementation or if you use the Kreait\Firebase\Messaging\RawMessageFromArray class, the message could be invalid, for example when you forget to add a message target.

use Kreait\Firebase\Exception\Messaging\InvalidMessage;

try {
    $messaging->send($message);
} catch (InvalidMessage $e) {
    echo $e->getMessage();
    print_r($e->errors());
}

Unknown registration tokens

If a message can’t be delivered to a given registration token although the token is syntactically correct, this usually has one of the following reasons:

  • The token has been unregistered from the project. This can happen when a user has logged out from the application on the given client, or if they have uninstalled or re-installed the application.

  • The token has been registered to a different Firebase project than the project you are using to send the message. A common reason for this is when you work with different application environments and are sending a message from one environment to a device in another environment.

use Kreait\Firebase\Exception\Messaging\NotFound;

try {
    $messaging->send($message);
} catch (NotFound $e) {
    echo $e->getMessage();
    print_r($e->errors());
    // If the message was send to a token, you can retrieve the unknown token
    echo $e->token();
}

Quota exceeded

The frequency of new subscriptions is rate-limited per project. If you send too many subscription requests in a short period of time, FCM servers will respond with a 429 RESOURCE_EXHAUSTED (“quota exceeded”) response.

use Kreait\Firebase\Exception\Messaging\QuotaExceeded;

try {
    $messaging->subscribeToTopic($topic, $registrationTokenOrTokens);
} catch (QuotaExceeded $e) {
    echo $e->getMessage();
    print_r($e->errors());
    $retryAfter= $e->retryAfter();
}

The QuotaExceeded exception provides a retryAfter() method which returns a DateTimeImmutable instance indicating when you can retry sending a subscription request.

Server errors

Sometimes, the Firebase servers are unavailable. If the server is kaputt, this will throw a ServerError exception, if it is “just” unavailable for the moment, this will throw a ServerUnavailable exception that provides a retryAfter() method which returns a DateTimeImmutable instance indicating when you can retry sending the request.

use Kreait\Firebase\Exception\Messaging\ServerError;
use Kreait\Firebase\Exception\Messaging\ServerUnavailable;

try {
    $messaging->send($message);
} catch (ServerUnavailable $e) {
    echo 'The FCM servers are currently unavailable: '.$e->getMessage();
    print_r($e->errors());
    $retryAfter= $e->retryAfter();
} catch (ServerError $e) {
    echo 'The FCM servers are broken: '.$e->getMessage();
    print_r($e->errors());
}

Error handling example

use Kreait\Firebase\Exception\Messaging as MessagingErrors;
use Kreait\Firebase\Exception\MessagingException;

try {
    $messaging->send($message);
} catch (MessagingErrors\NotFound $e) {
    echo 'The target device could not be found.';
} catch (MessagingErrors\InvalidMessage $e) {
    echo 'The given message is malformatted.';
} catch (MessagingErrors\ServerUnavailable $e) {
    $retryAfter = $e->retryAfter();

    echo 'The FCM servers are currently unavailable. Retrying at '.$retryAfter->format(\DATE_ATOM);

    // This is just an example. Using `sleep()` will block your script execution, don't do this.
    while ($retryAfter <= new DateTimeImmutable()) {
        sleep(1);
    }

    $messaging->send($message);
} catch (MessagingErrors\ServerError $e) {
    echo 'The FCM servers are down.';
} catch (MessagingException $e) {
    // Fallback handling
    echo 'Unable to send message: '.$e->getMessage();
}