Google API PHP Client - Firebase Cloud Messaging Service v1 example

send.php

<?php

/**
 * This serves as an example of how to use the Google API PHP Client 
 * with Firebase Cloud Messaging Service.
 *
 * The client can be found here:
 * https://github.com/google/google-api-php-client
 *
 * At the time of writing this, there's no Service object for the correct 
 * scope for Firebase Messaging, so here's an example of how this can be
 * done with provididing the scope manually.
 *
 * Info regarding authorization and requests can be found here:
 * https://firebase.google.com/docs/cloud-messaging/server
 */

require 'vendor/autoload.php';

$client = new Google_Client();

// Authentication with the GOOGLE_APPLICATION_CREDENTIALS environment variable
$client->useApplicationDefaultCredentials(); 

// Alternatively, provide the JSON authentication file directly.
$client->setAuthConfig(__DIR__.'/auth.json');

// Add the scope as a string (multiple scopes can be provided as an array)
$client->addScope('https://www.googleapis.com/auth/firebase.messaging');

// Returns an instance of GuzzleHttp\Client that authenticates with the Google API.
$httpClient = $client->authorize();

// Your Firebase project ID
$project = "myproject-4e6ed";

// Creates a notification for subscribers to the debug topic
$message = [
    "message" => [
        "topic" => "debug",
        "notification" => [
            "body" => "This is an FCM notification message!",
            "title" => "FCM Message",
        ]
    ]
];

// Send the Push Notification - use $response to inspect success or errors
$response = $httpClient->post("https://fcm.googleapis.com/v1/projects/{$project}/messages:send", ['json' => $message]);

Hello, Im using the service-account settings. However, I still get the error SENDER_ID_MISMATCH. Can someone help me?

@drussdev

The SENDER_ID_MISMATCH error typically occurs when the Firebase Cloud Messaging (FCM) request is sent with a token that doesn't match the sender ID associated with the service account credentials being used. Here’s a step-by-step example of how to correctly set up and use the Google API PHP Client for Firebase Cloud Messaging Service v1, ensuring you avoid this error:

Key Points to Ensure

1. Service Account JSON File: Make sure the path to the service account JSON file is correct.
2. Firebase Project ID: Ensure that the project ID matches the one in your Firebase project settings.
3. Device Token: Verify that the device token is valid and corresponds to the correct Firebase project.

Troubleshooting SENDER_ID_MISMATCH

• Token Validity: Ensure that the token you are using is from the same Firebase project associated with the service account credentials.
• Correct Project ID: Double-check that the firebaseProjectId in the script matches the project ID from the Firebase Console.
• Scope and Permissions: Ensure that the service account has the necessary permissions to send FCM messages. The scope used in the script (https://www.googleapis.com/auth/firebase.messaging) should be correct.

If you've verified all these points and still encounter the issue, it's possible that the token has expired or is invalid. In such cases, try generating a new device token and test again.

@abhishekpwo , Key Points to Ensure::3 is my reason. Thank you.

Great! Welcome.