Does FCM use APNS to deliver messages to an iOS app?

[Jeremy Colton]

https://developers.googleblog.com/2016/05/firebase-expands-to-become-unified-app.html says:

"Google Cloud Messaging, the most popular cloud-to-device push messaging service in the world, is integrating with Firebase and changing its name to Firebase Cloud Messaging (FCM). Available for free and for unlimited usage, FCM supports messaging on iOS, Android, and the Web, and is heavily optimized for reliability and battery-efficiency. "

Does "heavily optimized" mean 100% reliable?  If so I'd expect FCM NOT to use APNS to deliver messages to an iOS app, since APNS is not reliable and the user can disable push notifications per app. But I read at https://developers.google.com/cloud-messaging/ios/start that the needs an APNS certificate!  This implies that APNS is used!  So can anyone confirm if FCM use APNS when delivering a message to an iOS app?

Thanks.

[Tingmui Li]

Hi Jeremy,

  APNs needs to be used for push messaging when an application is in the background.

  Hence, FCM uses APNs to deliver messages when the message contains user visible payload, e.g., body, sound etc. 

  FCM also delivers via APNs when content available is set.

  We are actively exploring scenarios and flows to improve overall reliability, iOS devices included!

Thanks

[Thomas Au]

Hi Tingmui,

I am using Google Firebase Analytics in my IOS application.  Specifically, I am using only the Analytics part.  Nothing related to FCM is used.  When I submit the application to the Apple Store for approval, I got a warning back saying the application need to be signed with SSL APN certificate.  Do you know why that is, and how I can turn off any APN services that could be enabled implicitly?

Here is the message that I received from Apple:

Dear developer,

We have discovered one or more issues with your recent delivery for "myApplication". Your delivery was successful, but you may wish to correct the following issues in your next delivery:

Missing Push Notification Entitlement - Your app includes an API for Apple's Push Notification service, but the aps-environment entitlement is missing from the app's signature. To resolve this, make sure your App ID is enabled for push notification in the Provisioning Portal. Then, sign your app with a distribution provisioning profile that includes the aps-environment entitlement. This will create the correct signature, and you can resubmit your app. See "Provisioning and Development" in the Local and Push Notification Programming Guidefor more information. If your app does not use the Apple Push Notification service, no action is required. You may remove the API from future submissions to stop this warning. If you use a third-party framework, you may need to contact the developer for information on removing the API. 

After you’ve corrected the issues, you can use Xcode or Application Loader to upload a new binary to iTunes Connect.

Regards,

The App Store team