This is amazing! I love to see things like this, because push notifications are always a sticking point on mobile devices that aren't tied to Apple or Google. And this looks like it'll make it easier to get started if you already have an XMPP account.
Leveraging XMPP to deliver notifications for Matrix feels like an odd matchup. Or is that just because Synapse + FluffyChat support UnifiedPush and the use of XMPP is purely coincidental/incidental?
(Trying to wrap my head around the architecture too, with the last sentence there. Presumably the service and client need to know how to talk to the UnifiedPush provider?)
It is kinda weird. However, at the end of the day, UnifiedPush is just a protocol that allows $heavyProtocolA to receive notifications through $lightProtocolB.
And XMPP is just $lightProtocolB, there is nothing stopping an XMPP-based UnifiedPush distributor w/o messaging from existing. If you don't use XMPP for messaging, there are many simpler distributors available.
Is it really about light vs. heavy though? I thought it was mostly about multiplexing notifications through a single app (usually through a single connection as well), so only one app has to consume resources constantly, and others might be activated as needed.
It's a little bit of both. You want to only keep one connection open as it minimizes the amount of network activity for e.g. keepalives. You also don't want the app holding that connection open to drain the battery in the process though.
I've been using this for a day or so since it came out as a replacement for ntfy. It's been really solid so far and means I only have 2 apps that wake my phone up -- conversations (provides notifications for irc and fediverse stuff) and fair email.
I'm really hoping something comes along to provide email with webpush/unifiedpush notifications.
JMAP (IMAP+Submission replacement) has support for WebPush. If I have a minute I’ll implement UnifiedPush in https://Ltt.rs - Sadly JMAP doesn’t have a lot of server implementations. (Yet? Maybe)
That'd be quite cool :) I've been using maddy for a self hosted mail server, itd be nice to replace it with stalwart and give ltt.rs a try... and convince the hosted mail i use to start using a JMAP supported server
AFAIK Cyrus has JMAP support. We are using it for more than 20 years at work without any issues. However, we are lacking compelling client support for JMAP (via using SoGo via IMAP currently). Would be great to have a good static webclient for security reasons. Configurable notifications would be another plus.
My recent F-Droid blog post explained what UnifiedPush is in detail, basically:
> until now, the only option for push notifications was Google’s proprietary service, Firebase Cloud Messaging (FCM). UnifiedPush is a new alternative that allows you to get push notifications without being tied to a single company.
> Applications that support UnifiedPush can receive notifications via a dedicated UnifiedPush application that maintains a single server connection to receive all notifications. We call this “UnifiedPush application” a distributor;
Conversations is now a distributor, and UnifiedPush-supporting apps like Element or Tusy can receive notifications through it.
It seems kinda silly to just not provide an abstraction over Apple/Google notifications like Pushover does and then provide opportunistic use of new network.
If you compromise your ideals like a tiny bit you can build your network and be ubiquitous.
It's not about ideals, but technical limitations. UnifiedPush isn't an app like Pushover. It's plumbing/APIs for delivering notifications to apps, and it replaces the plumbing provided by the OS vendors. However, that's simply not possible on iOS (or if it is, as they say in the FAQ entry, please share how!).
If all you want is to get a generic message in front of a user, UnifiedPush isn't what you're looking for - just use Pushover, ntfy.sh apps or whatever for that. They use Apple's push notification APIs.
I don't have or want a Google or Apple account. I use a de-googled android phone running Lineage with MicroG. I'm glad for Unified Push because it means i can now get instant message notifications for supported apps, without which I would need to rely on SMS which can take up to 15 minutes to appear.
I am not willing to compromise my ideals. It there were no unified push, I would just live with delayed notifications of SMS, but this is better.
edit: corrected that I would have no notifications, not delayed notifications without unifid push.
But I personally would do it only when I can buy an OEM’s phone that supports a degoogled OS out of box. That would be not compromising my ideals in my case.
(I guess there might be one or two around, maybe in the West, but nothing in my geography).
There are a few, like fairphone, maybe shiftphones, and you can probably buy a few with /e/ pre-installed. You can also try any old phone supported by LineageOS.
For cross platform UnifiedPush libraries, such as Flutter, it totally makes sense to support iOS by wrapping APNS. Unfortunately, most people on the UP team don't have Apple devices, or iOS development experience. Maybe someday...
Mobile OSes (such as Android and iOS) heavily restrict what apps can do in the background, or even terminate them entirely when they are not in the foreground. This is to increase battery life, etc.
For many apps, notifications are important. Using Mastodon as an example - if someone mentions you on Mastodon, your app should tell you. But unless you actually have the app open, it won't be able to receive any notification from your Mastodon server due to the OS restrictions.
As a solution, the OS vendors created special services embedded into the OS that are allowed to maintain a persistent network connection to the OS vendor's cloud servers.
Then if an app developer wants their app to display a notification, they obtain an API key from the OS vendor and connect to the OS vendor's API and submit their notification to it.
The OS vendor's servers will then deliver the notification to the notification service on the device, the notification service will display it to the user or wake up the app.
Google's service (Firebase Cloud Messaging (FCM)) and Apple's Push Notification Service are proprietary things.
On Android, there are free and open-source apps that don't link to Google's proprietary components, including their notification service. F-Droid is an FLOSS "app store" that will not distribute apps using Google's APIs in their repository. Some "de-Googled" Android flavours remove the component entirely from the OS.
However some developers still would like a way for their app to receive notifications without constantly polling (repeatedly making requests to check for new data) in the background. It's annoying and not very efficient (for network usage or battery).
UnifiedPush is an open API/specification that provides an alternative to the proprietary APIs. It allows you to set up a "distributor" app which will relay notifications to the other apps on your device. The distributor app generally keeps a single open connection to a server, and waits for notifications to come in.
App developers can deliver notifications to the user's chosen notification server using a standard API, and know that it can reach their device. The OS vendors are no longer in the loop.
Conversations is a messaging app, usually used for chats/calls like any other. It uses an open messaging protocol called XMPP, which has a bunch of open-source servers and clients, and can be self-hosted. Conversations already maintains a connection to the XMPP server, and XMPP already has various optimizations to minimize network activity and battery usage.
The Conversations developer has developed a way to re-use the existing XMPP connection for notifications, as well as your messaging traffic. Conversations acts as a "distributor" and will relay notifications to other apps on your device that support UnifiedPush.
Why is a separate notification proxy better than letting apps run in background and take care of their notifications? A simple poll() shouldn't waste much CPU, right? I think that is what my IMAP client and the mentioned conversations XMPP client do.
Is the overhead of having 1 TCP connection in idle state really noticably better than having ~20, each for every app? How does UnifiedPush work with apps with traditional protocols, e. g. IMAP/XMPP - I assume the remote server itself must be logged in to your IMAP/XMPP.
I never fully understood Google's mobile notifications.
If every app held open a truly idle TCP connection, only exchanging data when necessary, you're right. Open idle connections are pretty lightweight.
There are a number of problems. One is that apps weren't doing that. It's too tempting for app developers to do things like HTTP polling instead. Then you have apps all polling at different intervals, and then on average the phone's radio is constantly in an active state even if the user isn't doing anything.
Even if apps correctly used persistent connections, it's actually tricky to maintain a persistent connection. There is a balance between reducing traffic and detecting that the connection has failed (using keep-alives, etc.). After a network transition, connections must be re-established. Doing that once is cheaper than doing it N times, once per app.
XMPP servers do support push notifications (e.g. via Apple/Google), though they aren't usually necessary on Android unless you have an overly aggressive one ( https://dontkillmyapp.com ). On iOS they're practically essential.
It makes less sense for XMPP clients to use UnifiedPush, because if you're in an environment where you are able to have something constantly running as a UnifiedPush distributor and maintaining a persistent connection, you might as well make that something be your XMPP app, which can reuse the same connection for more than one thing.
It isn't about using the CPU. It's about waking from sleep to keep the connection alive, and being able to kill background apps to save memory.
It's a battery saving feature.
UnifiedPush is just here so that an app can tell other apps it already maintains a persitent connection, and can forward notifications.
You'd have to sync TCP keepalives across different apps otherwise. Moreover, UnifiedPush is transport-agnostic. Here, it's XMPP. It could be SMS or LoRA too, handled by a low power microcontroller or the modem itself.
xmpp is great. I just wish the clients were better/more interoperable/more unified on sharing organization information. For example, gajim has these great workspaces where you can group conversations but it's all local to that install of gajim and it doesn't appear to be durable across closing conversations and getting new messages.
As a messaging protocol it appears to work well, it was relatively easy to get it running (although not as easy as matrix) and slidge is coming along nicely to provide interoperability with other chat platforms.
