FCM Throwing invalid-argument for IOS notifications

Question

My project had working notifications previously and I can't trace any changes to the payload I've been sending. I've referenced the docs and can't see any issues with my payload. The exact error I am getting is

Request contains an invalid argument

let payload = {
    token : oUser.devicetoken,
    data : {
        referenceid : chatid,
        referencetype : 'chat',
        referencename : oSender.displayname,
        receiverid : userid,
        type : 'message',
        notificationid : res,
        title : title,
        body : `${oSender.displayname} : ${body}`
    },
    android : {
        priority : 'high'
    },
    apns : {
        payload : {
            aps : {
                'content-available' : 1
            }
        },
        headers : {
            'apns-push-type' : 'background',
            'apns-priority' : '5',
            'apns-topic' : 'llc.attebyte.partyme'
        }
    }
};

My current payload:

After taking a fresh look at the Apple docs for notifications I noticed that I should be using content-available. I had previously been using contentAvailable: true (and it was working). Neither one is working anymore.

There are multiple questions regarding this problem already. This one being the best I've found: firebase cloud messaging Request contains an invalid argument

I verified that the token is correct by sending the device a test notification from the firebase console. I don't think I should be hitting the size limit of 4kb, the message I am sending for testing is something along the lines of 'test' or 'hello' (also the issue is IOS specifi). I've also verified that the headers I am sending are current with the Apple docs.

I can't figure out any differences that would cause notifications to stop working within the last week or so. I know they were working then and I've gone through my Github history to verify the payload hasn't changed (besides my change to content-available I made today while testing.)

Answer 1

While Google takes its time to fix this, we could successfully send silent notifications using the legacy app server protocols:

https://firebase.google.com/docs/cloud-messaging/send-message#send-messages-using-the-legacy-app-server-protocols

The endpoint we are using is https://fcm.googleapis.com/fcm/send.

Here you can find the message structure (note that is quite different from the current API):

https://firebase.google.com/docs/cloud-messaging/http-server-ref

And here how to authorize the requests:

https://firebase.google.com/docs/cloud-messaging/auth-server#authorize-http-requests

Hope it helps while we wait for a definitive fix.