---

labels:

- 'Stage-Beta'

summary: 'XEP-0357: Cloud push notifications'

---

Introduction

============

This is an implementation of the server bits of [XEP-0357: Push Notifications].

It allows clients to register an "app server" which is notified about new

messages while the user is offline, disconnected or the session is hibernated

by [mod_smacks]. 

Implementation of the "app server" is not included[^1].

**Please note: Multi client setups don't work properly if MAM is disabled and using this module won't change this at all!**

Details

=======

App servers are notified about offline messages, messages stored by [mod_mam]

or messages waiting in the smacks queue.

The business rules outlined [here](//mail.jabber.org/pipermail/standards/2016-February/030925.html) are all honored[^2].

To cooperate with [mod_smacks] this module consumes some events:

`smacks-ack-delayed`, `smacks-hibernation-start` and `smacks-hibernation-end`.

These events allow this module to send out notifications for messages received

while the session is hibernated by [mod_smacks] or even when smacks

acknowledgements for messages are delayed by a certain amount of seconds

configurable with the [mod_smacks] setting `smacks_max_ack_delay`.

The `smacks_max_ack_delay` setting allows to send out notifications to clients

which aren't already in smacks hibernation state (because the read timeout or

connection close didn't already happen) but also aren't responding to acknowledgement

request in a timely manner. This setting thus allows conversations to be smoother

under such circumstances.

The new event `cloud-notify-ping` can be used by any module to send out a cloud

notification to either all registered endpoints for the given user or only the endpoints

given in the event data.

The config setting `push_notification_important_body` can be used to specify an alternative

body text to send to the remote pubsub node if the stanza is encrypted or has a body.

This way the real contents of the message aren't revealed to the push appserver but it

can still see that the push is important.

This is used by Chatsecure on iOS to send out high priority pushes in those cases for example.

Configuration

=============

  Option                               Default           Description

  ------------------------------------ ----------------- -------------------------------------------------------------------------------------------------------------------

  `push_max_errors`                    `16`              How much persistent push errors are tolerated before notifications for the identifier in question are disabled

  `push_notification_important_body`   `New Message!`    The body text to use when the stanza is important (see above), no message body is sent if this is empty

  `push_max_devices`                   `5`               The number of allowed devices per user (the oldest devices are automatically removed if this threshold is reached)

  `push_max_hibernation_timeout`       `6220800`         Number of seconds to extend the smacks timeout if no push was triggered yet (default: 72 hours)

There are privacy implications for enabling these options because

plaintext content and metadata will be shared with centralized servers

(the pubsub node) run by arbitrary app developers.

Installation

============

Same as any other module.

Configuration

=============

Configured in-band by supporting clients.

Compatibility

=============

------ -----------------------------------------------------------------------------

  trunk  Works

  0.12   Works

  0.11   Works

  0.10   Works

  0.9    Support dropped, use last supported version [675726ab06d3](//hg.prosody.im/prosody-modules/raw-file/675726ab06d3/mod_cloud_notify/mod_cloud_notify.lua)

------ -----------------------------------------------------------------------------

[^1]: The service which is expected to forward notifications to something like Google Cloud Messaging or Apple Notification Service

[^2]: [business_rules.markdown](//hg.prosody.im/prosody-modules/file/tip/mod_cloud_notify/business_rules.markdown)