Ably can deliver native push notifications to devices using, amongst others, Apple’s Push Notification service and Google’s Cloud Messaging service. Native push notifications, unlike Ably’s channel based pub/sub messaging, do not require the device to maintain a connection to Ably as the underlying platform or OS is responsible for maintaining its own battery efficient transport to receive push notifications. Therefore, native push notifications are commonly used to display visual notifications to users or launch a background process for an app in a battery efficient manner.
Ably’s push notification service is currently in beta. Please bear in mind:
- Whilst the API we provide now is planned for our GA release, the API is subject to change. However, we will endeavour to only make changes to the API where necessary before we transition the service to GA (general availability).
- The push service, as far as we are aware, is ready for production levels of usage. However, given the beta status, push notifications have not yet been stress tested under real-world production loads. As a result, you should expect some bugs. If you experience any problems, please get in touch and we’ll work as quickly as possible to help identify the problem and fix it.
- The client libraries currently have varying levels of support for push notifications. Please refer to the push notification client library download section for details on how to use push on your devices and servers now.
- Push notification statistics are currently disabled. Therefore, you are not currently charged for push notifications and and the push notification stats in your app dashboard will be zero. Please note that each push notification, when stats are enabled, will count as one message from a billing perspective. We plan to enable push statistics soon, get in touch if you need statistics now.
- Documentation is not complete. We’ll be continuing to add more documentation over the coming weeks. However if you have any specific questions or recommendations in regards to how we can improve the documentation, please do get in touch
Delivering push notifications
Ably provides two models for delivering push notifications to devices:
The model for delivering push notifications to devices over channels is intentionally very similar to how “normal” messages are delivered using Ably’s pub/sub channel. For example, a “normal” message published on an Ably channel is broadcasted immediately to all subscribers of that channel. When broadcasting push notifications on channels however, the process is the same with the exception that the subscribers (devices receiving push notifications) are registered in advance using our API and the message itself must contain an extra push notification payload that specifies the optional visual format and optional data payload of the native push notification.
Ably provides a REST API that allows native push notifications to be delivered directly to:
- Devices identified by their unique device ID
- Devices identified by their assigned
- Devices identified by their native recipient attributes such as their unique
registrationTokenin the case of GCM,
deviceTokenin the case of APNS, or
encryptionKeyin the case of a Web device. This means is particularly useful when migrating to Ably with existing push notification target devices.
Activating a device and receiving notifications
Every device that will receive push notifications must activate itself with the local operating system or framework, and hook into the push notification services that the underlying platform provides. This functionality is platform specific and varies considerably across not just platforms, but also across the push services that operate on those platforms such as GCM and FCM, both of which are available on the Android platform.
The Ably client libraries aim to abstract away this complexity and platform specific behaviour by providing a consistent API for device activation, maintenance of the device registration, subscription to Ably channels for receiving push notifications, and of course for receiving the native push notifications themselves.
Managing devices and subscriptions
Whilst the realtime client libraries provide APIs for a device to activate itself (via
client.push) and subscribe for push notifications (via
channel.push), those APIs are intentionally limited to actions pertaining to the device it is run on.
A separate and distinct push admin API is additionally provided in our client libraries specifically designed for use by your servers to facilitate managing and delivering push notifications across all of your registered devices. This API, amongst other things, includes features to manage registered devices, channel subscriptions and deliver push notifications directly.
Ably currently supports push notifications on the following platforms:
- Apple Push Notifications
- supported on all mobile devices running iOS, desktop devices running OS X and Safari
- Google Cloud Messaging
- supported on all Android and iOS devices, although we use GCM exclusively for Android message delivery
- Firebase Cloud Messaging
- supported on all Android and iOS devices, although we use FCM exclusively for Android message delivery
- Web Push API
Downloading a client library with push support
As Ably’s push notification service is currently in beta, the client libraries currently have varying levels of support for push notifications.