Firebase Cloud Message not multicast_id received in response

Question

I send notifications in my server with PHP to FCM with this function:

function sendGCM($ch1,$ch2, $message) {

    $url = 'https://fcm.googleapis.com/fcm/send';

    $fields = array (
            'to' => $ch1
            ,
            'data' => array (
                    "message" => $message
            )
    );
    $fields = json_encode ( $fields );

    $headers = array (
            'Authorization: key=' . $appID,
            'Content-Type: application/json'
    );

    $ch = curl_init ();
    curl_setopt ( $ch, CURLOPT_URL, $url );
    curl_setopt ( $ch, CURLOPT_POST, true );
    curl_setopt ( $ch, CURLOPT_HTTPHEADER, $headers );
    curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
    curl_setopt ( $ch, CURLOPT_POSTFIELDS, $fields );

    $result = curl_exec ( $ch );

    curl_close ( $ch );
    echo $result;
}

The response is this {"message_id":9191006033691432523}. In the documentation, https://firebase.google.com/docs/cloud-messaging/http-server-ref multicast_id, success, failure parameters are required in the response but.

What is the reason for this?

Possible duplicate of multicast id in firebase cloud messaging service — AL.

Sebastian Tkaczyk Sebastian Tkaczyk · Accepted Answer · 2017-08-26T13:42:03

You are sending message to specified by $ch1 topic, if I understand ok, instead to multiple devices by their registrationIds.

So you are reciving Topic message HTTP response body (JSON) (table 6) instead of Downstream HTTP messages

Firebase Cloud Message not multicast_id received in response

2 Answers