Libervia progress note 2023-W22

goffi 31/05/2023, 20:39 jabber-xmpp-en SàT Libervia project libre Libervia progress SàT progress XMPP


It's been a while since my last progress note. I've been immersed in work on Libervia, with many tasks to accomplish. I'll keep this update brief.

A/V Implementation in Libervia

I'm thrilled to announce a new development that I haven't yet officially shared on this blog: Libervia has once again received a grant from NLnet, this time via the NGI Assure Fund. This funding will facilitate the implementation of A/V calls with Jingle across several frontends: Web, Desktop, and CLI. In addition to one-on-one calls, multi-party calls are in the plans. The first approach will be using XEP-0272: Multiparty Jingle (Muji), which supports Peer-to-Peer (P2P) connections between participants without the need for a specific service—ideal for a small number of participants. For larger groups, a Selective Forwarding Unit (SFU) will be used, mirroring the technology used in platforms such as Jitsi Meet.

Alongside calls, we plan to offer Desktop Sharing, and even a specification and implementation for Remote Desktop Control atop XMPP!

Progress is well underway; one-on-one calls are already functional within the web frontend. However, there is still substantial work ahead.

To gain insight into the related tasks and what we've accomplished so far, you can check the associated tickets.

ActivityPub Gateway

I realize the high level of anticipation surrounding this gateway. While the gateway is operational (this blog utilizes it), it is yet to stabilize. I had hoped early adopters would install it and provide bug reports or other feedback. Unfortunately, this was not the case, with only one person (to my knowledge) having used it and provided prior feedback. This is understandable considering the requirement of an existing XMPP server, installation of a dev version of Libervia, and setting everything up. If you wish to try it out, you're welcome to join our official chat at (http link).

Nonetheless, I've decided to adjust my strategy. At some point, I plan to open a test instance. Due to limited resources for moderation, it will likely be invitation-only initially. The ultimate aim is to gather sufficient feedback to ensure stability.

Official Website and Test Instance

There have been several changes to the website:

  • The Flatpak and Docker images appeared to be malfunctioning. I've temporarily removed them and plan to rectify this issue later. If you wish to test Libervia in the meantime, the sources remain available.

  • I've added a roadmap at Many had requested this, so here you go.

I've discontinued the test instance, after years of service, as I've relocated the official website there to align with the project's new name (Libervia versus formerly Salut à Toi). As mentioned above, I have plans for a new instance, but it will likely be invite-only initially. I'm also considering a local-only demo for a quick overview of the web frontend—a non-federated feature that self-resets every few hours. We'll see if I can make the time to set it up.


I'll be delivering two talks next month in Paris:

I would be delighted to engage in a conversation if you happen to be there.


In addition to these projects, I've been focusing on parallel tasks like code refactoring, work on calendar events, and the web frontend. However, I'll delve into these topics in more detail at a later date.

That's all for this note.

Libervia progress note 2022-W45

goffi 24/11/2022, 11:58 jabber-xmpp-en SàT Libervia project libre Libervia progress SàT progress XMPP

Hello, it's time for a long overdue progress note.

I'll talk here about the work made on ActivityPub (AP) gateway and on end-to-end encryption around pubsub.

Oh, and if everything goes well, this blog post should be accessible from XMPP and ActivityPub (and HTTP and ATOM feed), using the same identifier


The work made on the AP gateway has been possible thanks to a NLnet/NGI0 grant (with financial support from the European Commission's Next Generation Internet programme).

I especially appreciated that the team was really there to help bring the ideas to life, and not once did they get in the way: little paperwork, no unnecessary pressure, caring, contacts when help was needed, etc.

I wish there were more organizations like this one that really help develop libre projects for the common good.

So once again I want to thank them for all that.

XMPP ⬌ ActivityPub Gateway

There is probably no need to explain here what is ActivityPub, we can simply write that it is an open protocol that allows to do things that XMPP also allows doing, and that until now these 2 protocols could not communicate together. The work on the ActivityPub gateway aims to allow software implementing one of these 2 protocols to communicate as easily as possible. I firmly believe that all open protocols should be able to communicate which each other, to avoid creating more silos, proprietary software is already good enough at that.

To be useful, a gateway must use the full potential of both protocols. A simple bot transcribing messages as we see too often, using unsuitable features (such as instant messaging for blog posts), or using a very limited set of features to ensure compatibility are flaws that I have tried to avoid. Building a good gateway is a difficult and time-consuming task. If done right, the gateway should be as invisible as possible to the end user.

XMPP is featuring blogging since long before AP, however the set of features is not exactly the same. Current use of AP is clearly inspired from commercial "social" networks, and metadata such as subscribers/subscribed nodes (or followers/following in AP terms) are highlighted, feature such as like/favourite were missing in XMPP, and some implementation such as Pleroma do implement reactions. To integrate that in the gateway, I've been working on new specifications:

  • Pubsub Public Subscriptions: a way to publicly announce subscriptions, in an opt-in way. With this it's possible to implement followers/following features in a way respectful of privacy.

  • Pubsub Attachments: a generic way to attach any kind of data to a pubsub item. It's notably used to implements noticed/favourite button (see here and reactions.

  • Calendar Events: handling of events and all the RSVP mechanism. Libervia was handling events for years, but it was an experimental implementation, this specification is a next step in the effort to make it a standard.

Note that this XEP and the others linked below have been accepted but are not yet visible in official list.

You may wonder why there is a specification for Calendar Events… It's because the AP gateway also handles them, making it compatible with Mobilizon. The gateway may evolve in the future to support other non (micro)blogging use cases.

The gateway is now finished in terms of functionalities, however the code is clearly of an alpha quality for the moment. Now the goal in the coming months will be to stabilize and possibly implement other features if there is a demand for it.

Early adopters are encouraged to try and test it as long as they keep in mind that it's not stable. So if you do try it, I recommend keeping a separate ActivityPub account in whatever stable implementation you use at the moment, this way you can check if messages or media are missing, if there is any inconsistency or other bugs, and report them to me. If you test it, please join the XMPP room (click here to connect from your browser) for help and feedback. Stabilization will probably take weeks, but I hope to have it done by early 2023.

Installation instructions and details on how the conversion between protocols is done is available in the documentation and notably here

A question I've been asked a lot: yes, you can use the same identifier for XMPP (JID) and AP (WebFinger actor handle) as long as you use "simple" characters (i.e. alphanumeric ASCII chars, _, . and -). If you use something more complicated, you'll have to use the escaping mechanism explained in the doc (this is due to constraints with some AP implementations).

As for blogs on pubsub nodes (what Movim calls "communities"), I made it simple: you can use directly the name of the node that holds the blog in the local part (i.e. before the "@") of your actor handle: a blog named community_bog at the XMPP pubsub service can thus be addressed with the AP actor This way you can use a rather user-friendly identifier to share your blog with people who are only on ActivityPub.

This gateway should work with any XMPP server, and any client that implement blogging features (Only Libervia itself and Movim implement it for now, but I have heard that other clients are planning support for it). To enjoy the whole feature set of the gateway, the new specifications need to be implemented by the clients, so you can start to fill feature requests…

With this gateway, the door is open to have a client able to talk to the ActivityPub network, while having the feature of XMPP, including e2e encrypted private messages (e2e encrypted only if you communicate with an XMPP account, not with an AP one).

Oh, and please update your graphics, drawing and other texts to include XMPP in the fediverse ;)

End-to-End Encryption

Much effort has also gone into end-to-end encryption.

OMEMO implementation has been updated (OMEMO:2 is now used), including Stanza Content Encryption which allows encrypting arbitrary elements instead of only the \<body/> of the message, I believe that Libervia is the first XMPP client to implement it. OpenPGP for XMPP (or "OX") has also been implemented, all that thanks to the work of Tim Henkes "Syndace", the author of python-omemo.

Beside instant messaging, end-to-end encryption has also been introduced to pubsub. I've made specifications for two methods:

  • An OpenPGP profile for pubsub which is thought to encrypt a whole node, with a system of secret sharing/rotation/revocation. With it, it is easy to give access to new entities after publication, and to retrieve old items for newcomers. This specification can be used to encrypt any pubsub based features: (micro)blogging, calendar events, lists, etc.

  • Pubsub Targeted Encryption which is a way to apply the same cryptographic system used in instant messaging to pubsub. This way, OMEMO can be used with its forward secrecy property. It is not a good option to use this specification to encrypt a whole node, as archive is then not accessible to newcomers, and to add access to a new entity you have to re-encrypt all items, but it's an interesting option to encrypt an element occasionally, for instance to restrict access of a specific post in an otherwise public blog.

Specifications have also been written to sign a pubsub item in a backward compatible way (client which don't implement those specifications can still work normally):

All those specifications are already implemented in Libervia, but they are only usable from CLI frontend at the moment. All you have to do is to use the --encrypt and/or --sign options from pubsub or blog commands (check documentation for details).

Uploaded files were already encrypted with OMEMO Media Sharing which is what is commonly used these days, but this method has not been accepted as a standard as it was a workaround for limitation of legacy OMEMO implementation. The proper way is now specified with Stateless File Sharing and is encrypted with Encryption For Stateless File Sharing. Those methods are currently only usable when OMEMO:2 is implemented in the peer client, and with them metadata on the shared file can be attached, including thumbnails.

Encryption has also been implemented for Jingle (XEP-0391 and XEP-0396), which is notably used for Jingle File Transfer (specially useful for large files transfers).

So to summarize, nearly everything (instant messaging, files uploaded, large file transfers, all pubsub related features) can now be e2e encrypted with Libervia.

Possible Future

With the AP gateway permitting to reach the whole AP network, all the new features implemented, and the work done on e2e encryption, Libervia has everything to be a solid option for communication. After the recent events regarding a famous commercial network, we see a breakthrough of ActivityPub that will hopefully last over time. We can now access AP from XMPP, while having the possibility to have e2e encrypted private conversations or even blogs or calendar events.

As far as I know this is, so far, something unique for a Libre decentralized software. However, there is still work to do on stabilization on UI/UX update before this is really usable.

Those feature were planned for very long (years), but the lack of resources made them slow to come. The grant has made it possible to greatly accelerate the pace of development, and I doubt that it would have been possible to have all that without it.

Regarding how large the project is, and my family life, it's not possible any more to develop seriously this project on my free time alone (and I would like to do other things, sometimes, of my free time).

In other words, I need to find a way to sustain the development of Libervia for the years to come, so I can work full-time on it, and with some luck, build a team. I'm thinking very seriously about it these days, I'll probably write on this topic in a little while. If you are willing to help in any way, please contact me (on the Libervia room linked above for instance).

That's all for this progress note. I'm now working on stabilization and UI/UX update on the web frontend.

Libervia v0.8 « La Cecília »

goffi 30/11/2021, 22:51 jabber-xmpp-en SàT Libervia project libre release

I'm proud to announce the release of Libervia 0.8 « La Cecília » (formerly known as « Salut à Toi »), after more than 2 years of development.

This version is a big milestone preparing the future of the project. Let's have an overview of some major changes.

Project Renaming

In the interest of simplicity, the project has been renamed to " Libervia " (with was formerly the name of the web frontend), and all official frontends have now a straightforward name such as Libervia Web , Libervia Desktop / Mobile (same frontend for both), Libervia CLI for Command-Line Interface , and Libervia TUI for Terminal User Interface. The backend is, as you can guess, Libervia Backend. The former names are for now still used as aliases.

Beside simplicity, the name change was also due to concerns with international audience: some people were thinking that "Salut à Toi" was dedicated to French-speaking people only. Hopefully, it will be easier for everybody, and people won't get confused any more by all the names which were previously used.

Note that the renaming has implications on your configuration file which is now named libervia.conf (sat.conf is still working for now). The sections have been updated with new names (to configure the CLI frontend you now use [cli] section instead of [jp], for the web frontend it's now [web] instead of [libervia]). Please check documentation in case of doubt.

Technical Changes

Libervia has been ported to Python 3, which has opened the door to other changes.

Brython has been integrated to Libervia Web, to replace the unmaintained "Pyjamas" (which was a Python port of GWT).

Nunjucks is also now integrated in Libervia Web, making it possible to share some templates with Jinja. This is notably useful to make some pages working with or without JavaScript.

OMEMO implementation has been completed with support for MUCs (group chats) and files (via XEP-0454: OMEMO Media Sharing).

Many other changes are not explained in this note to avoid it being indigestible, you can check the CHANGELOG for more information.

Libervia Web New Default Theme

A new theme for Libervia Web based on the nice Bulma CSS framework has been made and is now the default one. Thanks to it the interface is clearer and more pleasant to use.

Events list with the new theme


An easy to use invitation system has been implemented in Web frontend, and can be used either to give access to something to somebody with an existing XMPP account, or to invite somebody by email. The goal is to be able to share things (e.g. photo album, event) with family or friends without having to expect them to install a software or create an account.

Inviting people to see a photo album


A decentralised issue tracking system was implemented since version 0.7, which was notably used to manage Libervia's own tickets. It was using a non-standard feature available only in Libervia Pubsub (formerly "SàT Pubsub", server independent Pubsub/PEP component, a side project).

This feature has been renamed to "Lists" and now uses XEP-0346: Form Discovery and Publishing which makes it usable with a generic Pubsub service.

Any kind of list can be created, from project tickets to keep track of bug report of feature requests, to To-do list, grocery list, etc. Being based on XMPP pubsub, lists can be federated, and permissions can be managed easily (for instance to allow various family members to modify a shopping list).

Grocery List on Libervia Web

For the moment 3 kinds of lists are available (generic tickets, To-Do, grocery), but more are expected to come in future versions.

Photo albums

Lots of improvements have been made on the photo albums in the web frontend. They can now be created or deleted from Libervia Web, photos or videos can be uploaded, a touch/mobile-friendly slideshow is available, ogv.js has been integrated to make possible the viewing of videos in Ogg Vorbis/Opus/Theora ans WebM VP8/VP9/AV1 on platforms not supporting them natively, and the invitation system mentioned above has been integrated.

you can now use a slideshow to see your photos and videos


Libervia Desktop UI has also been updated, the top menu has been removed, file dropping is now possible on suitable platforms, chat has infinite scrolling, a new "chat selector" screen makes it easier to select entity to chat with or room to join, message attachments are show in a more user-friendly way, and several other improvements has been done.

Chat Selector on Libervia Desktop

Work has also been done on Libervia Mobile (which is Android only for now), but this frontend is not user-friendly enough yet for end-user.

Attachment on Libervia Mobile


The CLI frontend is now fully documented and following the renaming can now be accessed either by libervia-cli or the shorter li (legacy jp is still working for now). Among new commands we can highlight li file get which retrieve a file with support of aesgcm scheme (i.e. OMEMO Media Sharing), which makes it a kind of OMEMO enabled wget like. li file upload also handle end-to-end encryption, it's thus easy to share an encrypted file from command-line or a script.

Background colour is now automatically detected on compatible terminal emulator, and theme is adapted consequently.

But Also…

File Sharing Component

Libervia can act as a component (which can be seen as generic XMPP server plugins), and it includes a File Sharing Component.

This component store files which can be retrieved either according to given permissions or publicly.

Files can be uploaded or downloaded via XEP-0234: Jingle File Transfer and XEP-0363: HTTP File Upload is now also implemented, making it possible to share files via HTTPS link.

This component can now be used to replace internal XMPP servers HTTP File Upload implementations. In addition to the fine permission management, it does not have a size limit and user quotas can be set, check the documentation to see how to set them. Files uploaded can be retrieved using XEP-0329: File Information Sharing and deleted with XEP-0050: Ad-Hoc Commands.

This component is necessary to use the Photo Album feature.

Libervia Pubsub

A Pubsub/PEP component (formerly named "SàT Pubsub") is developed next to Libervia. It aims to provide a server independent feature-full implementation.

Libervia Pubsub is released at the same time as the Libervia XMPP client, and has also been ported to Python 3.

Among novelties, Full-Text Search has been implemented (XEP-0431: Full Text Search in MAM), as well as XEP-0346: Form Discovery and Publishing which replaces the former non-standard node schema, and PEP is now working for the server itself, making it usable for XEP-0455: Service Outage Status.

Docker Images

Docker images have been updated and moved directly to libervia-backend repository (in docker subdirectory).

Official Website

The Official Website has been updated with a new theme (based on Libervia Web new theme).


Libervia is available on several GNU/Linux distributions (at least Debian and derivative and Arch Linux). Unfortunately, the current Debian version is outdated (due to incompatible Debian and Libervia release dates), hopefully the new version will be available as a backport soon.

You can easily install Libervia on any distribution by using pipx:

$ pipx install libervia-backend
$ pipx install libervia-desktop

Then launch libervia-backend, and a frontend (e.g. libervia-cli or libervia-desktop). Check the documentation for details.

Docker images are available, and notably a web-demo.yml file can be used with docker-compose to quickly try a local demo:

$ hg clone 
$ cd libervia-backend/docker
$ docker-compose -f web-demo.yml up

Then open your browser on http://localhost:8880 and use the login demo with password demo.

What's Next

A Libervia based project has been selected by NLnet for a grant. This project is in 2 parts: working on an XMPP ⟺ ActivityPub gateway, then on pubsub and files end-to-end encryption. You'll find more information on this blog post and on NLnet project page. The project has already well started, and you can follow the progress on my blog (which is Libervia/XMPP powered) or on the ticket tracker (which is also Libervia/XMPP powered). A huge thanks to NLnet/NGI0 Discovery Fund!

Besides, work is planned to improve user experience and instant messaging feature (notably on Web frontend). Libervia aims to be a good fit for private networks for family and friends.

Last but not least, I've been pleased to see that Libervia Web is used to power blog. JMP is a company which give you a real phone number which can be used with XMPP and SIP (you can call this number from a traditional phone and get the voice call from a XMPP client).

This concludes this release post. Stay tuned!

debacle 01/12/2021, 01:07


sthaan 02/12/2021, 16:52

Libervia progress note 2021-W38

goffi 27/09/2021, 06:54 jabber-xmpp-en SàT Libervia project libre Libervia progress SàT progress


it's time for a new progress note. The work is currently focused on ActivityPub Gateway, and progress has been done on pubsub cache search and the base component.

Pubsub Cache Full-Text Search

Next to the pubsub cache implementation, it was necessary to have a good way to search among items.

So far, Libervia was doing pubsub search using pubsub service's capabilities, and notably the XEP-0431(Full Text Search in MAM) implementation. This is working well (it's what is currently used on this very blog when you do use the search box), but has some pitfalls: the pubsub service must implement this XEP (and as far as I know, Libervia Pubsub is the only one which does it at the moment), the search can be done in a single node at a time only, each search request imply a new XMPP request to the pubsub service, and pubsub items must be in plain text (which is currently always the case, but pubsub end-to-end encryption is planned as second part of the granted NLNet project on which I'm working).

In regard to that, a local search is necessary. SQLAlchemy doesn't really have Full-Text Search (or FTS) support for SQLite out of the box, but it allows to use any SQL directly, thus I could use the really nice FTS engine available within it (FTS5). This is an extension, but in practice it is already installed most of the time (it is part of the SQLite amalgamation).

Thanks to the JSON support in SQLite, it is also possible to filter search requests on parsed data. That's really useful for features like blogs where you often want to do that (e.g. filtering on tags).

The cache search can be operated on all data in cache, that means that you can do search on items coming from multiple nodes and even multiple services. That opens the door to features like hashtags or blog suggestions.

Last but not least, search requests can be ordered by any parsed field. In other terms it will be possible to order a blog by declared publication date — which may be important if you want to import a blog —, or events by location.

To have an idea of the possibilities, you can check the documentation of the CLI search command.

Base ActivityPub Component

Once the preparatory steps have been done, the ActivityPub component itself could be started. In short, for people not used to XMPP, a "component" is a kind of generic plugin to server. You declare it in your server configuration, choose a JID and a "shared secret" (a password), run it with those parameters, and voilà.

For the AP gateway, Libervia runs the component. There is documentation to explain how to launch it, don't worry it's simple.

As I've got questions about this, here is a small schema giving an overview on how the whole thing is working:

global overview of Libervia ActivityPub Gateway

I hope that it makes the whole thing more clear, otherwise don't hesitate to ask me for clarification.

As you can see, the gateway includes an HTTP server to communicate with AP software, but in many cases there will already be an HTTP server (website, XMPP web client, etc.). In this case, you'll have to redirect /.well-known/webfinger and /_ap requests to the gateway server.

For the development, I'm using Prosody as reference XMPP server implementation, and Mastodon as reference ActivityPub server implementation. I've set a local Mastodon installation, and I've chosen to use Docker for that, as it makes things easy to have a reproducible environment and to save and restore a specific state. It was not as trivial as I would expect to find the right configuration to use, I've found outdated tutorials, but I could manage to run the thing relatively easily.

Because we work with HTTPS, I've made a custom docker image with locale certification authority, so Mastodon could validate my gateway HTTP server certificate. I'm already doing that for docker image used for end-to-end tests of Libervia, nothing difficult. Surprisingly though, Mastodon could not resolve my instance, when HTTPie running from the same container could do it flawlessly. I've quickly realised that Mastodon was not respecting hosts declared in /etc/hosts (and added via extra_hosts in Compose file) and found a relevant bug report on Mastodon tracker. That was annoying, and I had to find a way to work around that. I've done it by running a local DNS Server, and Twisted offers a nice built-in one. Twisted DNS can easily use /etc/hosts to direct my local domains to my local IP, it's just a one liner such as twistd3 -n dns --hosts-file=/etc/hosts -r.

After that the domain was resolving, but to my surprise, Mastodon was still not able to communicate with my gateway, and even more bizarre my server was receiving no request at all. After a quick round of tcpdump/wireshark, I saw that indeed nothing was sent to my server.

Thanks to the Libre nature of Mastodon, I could resolve this by reading the source code, the Mastodon::HostValidationError
led me to a section that made the whole picture clear: my server is on a local IP and Mastodon by default refuses to reach it (to avoid the confused deputy attack). With the ALLOWED_PRIVATE_ADDRESSES setting I could finally make Mastodon communicate with my server.

The How to implement a basic ActivityPub server tutorial made by Eugen Rochko (Mastodon original developer) is a nice article to start an ActivityPub implementation, it has been useful to build the base component (despite being a bit outdated, notably regarding signature).

I have to rant a bit, though, as the ActivityPub specification are not available in EPUB or PDF, making it difficult to read on an e-book reader. I could overcome that thanks to pandoc (git clone then pandoc index.html --pdf-engine=xelatex -o activitypub.pdf), it's really more comfortable to keep the reference like this.

So the base component is now available but only usable by developers (and only capable of sending message to ActivityPub for now). Things will be really exiting with the next 2 steps, as bidirectional communications will be available, and the gateway will be usable for early adopters. I don't expect those steps to be really long.

test message sent with Libervia AP Gateway

Oh, and to answer another question that I've had, yes you can use the same ActivityPub actor identifier as your XMPP JID. I'll explain next time how everything is accessed.

That's all for today.

debacle 27/09/2021, 08:02


matlag 28/09/2021, 00:30


sthaan 14/11/2021, 19:48

Libervia progress note 2021-W31

goffi 03/08/2021, 11:03 jabber-xmpp-en SàT Libervia project libre Libervia progress SàT progress


last weeks have been exhausting with lot of things at the same time. I've been preparing the release of the 0.8 version, and I wanted to have a couple of thing ready for that, notably a proper way to do translation.

Preparation of 0.8

As you may know, I've implemented a docker integration into Libervia to be able to run relatively easily third party software. This is working, but when testing in the production website I had to put the finishing touches to make it work (notably I've improved HTTP proxy and HTTPS management). I have then created projects and updated a couple of translations files.

As you can now see on, there is a translate menu. Unfortunately I've closed the account creation for the moment, as I have to deal with licensing first. Indeed, nearly all Libervia ecosystem is for now in AGPL v3+, as there are only a few contributors (2 mains one, then only a small patches). The intent was and still is to be sure that the ecosystem stays in an Libre license, but this license may cause trouble in some edge cases, notably if we want to make an iOS frontend (the fruit store is notoriously causing trouble with AGPL licences).

Thus, I'll bring the subject at next general assemble of the "Salut à Toi" association, and see what we should do. One option could be to use FSF's Fiducial Licence Agreement to let the association the possibility to modify the licence as long as it stays a libre one. It would then be possible to add an exception for an iOS frontend. An other would be to avoid totally iOS. Anyway, this need some time and discussions, and if I open translations and get several contributions under AGPL v3+, it may be harder to set this up.

Weblate integrated in the official website

An other time consuming task was to continue with renaming and adapt package names (notably in Pypi). I've used a little trick to redirect legacy packages to the new ones: a new version of each legacy package is a simple depending on the new package (you can see it e.g. for sat package). I've also put in place a redirection on the Mercurial repositories, using the old repos will redirect to the new ones.

Finally, I've published the 0.8.0 beta 1. You can install it easily with pipx:

  • First install pipx as explained in its documentation
  • Then install the backend with pipx install libervia-backend. You can follow the documentation to see how to configure it and launch it. This will include the CLI and TUI frontends.
  • If you want to test graphical frontends, you'll have to install Libervia Media with hg clone (assuming that you have Mercurial already installed), then add it into your libervia.conf
  • To install the Desktop frontend, use pipx install libervia-desktop
  • To install the Web frontend, use pipx install libervia-web

Note that the Desktop frontend is still for early adopters, I need to refactor message handling and do some optimisation and stabilisation to make it pleasant to use.

Please send feedbacks either as bug reports/feature requests on the official bug tracker, or on the XMPP chat room at I plan to only fix major issues though, as I'm now fully working on 0.9 and I'm focusing mainly on the ActivityPub gateway. However, bug reports/feature requests will be taken into account for 0.9 if not fixed directly in 0.8.

ActivityPub Gateway

After the hard work to move 0.8 close to the finish line has been done, I've started to work on 0.9 and thus the ActivityPub gateway. The first major thing to do was a refactoring of offline storage. Indeed Libervia (or SàT at the time) was started a long time ago with an Async framework (Twisted) long before asyncio even existed. SQLite has been chosen as backend to store data, and a hand made module based on Twisted's adbapi has been created. Despite the rough edges is has been working quite well all this time, and there was even a semi automatic way to update schemas between version. But the whole thing was starting to be difficult to maintain, and the schema update instructions were all kept in the same file.

Fortunately, SQLAlchemy, the most famous SQL databases abstraction with an optional Object Relational Mapper has recently added support for asyncio.

SQLAlchemy is a very powerful and widely used tool, so it has been a quite obvious decision to use it to replace the old system. But to use it, Twisted needs to use an asyncio loop, and Libervia was using GLib loop (or reactor in Twisted terms), due to the dependency to dbus-python.

Dbus-Python is, by its own authors words, not be the best D-Bus binding to use due to unfortunate design decision, so it was the occasion to replace it, and I've moved the backend to TxDBus, a Twisted native D-Bus implementation, which can run with any Twisted reactor. For technical reason, dbus-python is still used for frontends at the moment, but I plan to completely replace it before the end of 0.9 development.

This has required some work, but it was worth it, and after that I could switch to asyncio reactor and implement SQLAlchemy. I've decided to go with the ORM and not the core only as it is opening neat possibilities. I've first made a mapping corresponding to the last version of the database used for Libervia 0.8.

Once SQLAlchemy has been implemented and working, the next obvious decision was to use Alembic, the recommended SQLAlchemy based database migration tools (by the same authors). Thanks to this, migration files are now in separated files, and are really easy to create (Alembic can autogenerate a good part of a script when a migration is needed).

Thanks to all this, I can now easily make changes in database (while in old system I was hesitating due to the work implied). SQLAlchemy also paves the way to support other databases than SQLite. Even if I'm currently sticking with SQLite only, to keep focus, I'll probably add support for PostgreSQL and MariaDB/MySQL at some point.

Once all this work on storage backend has been finalised, the pubsub cache has been implemented.

Pubsub cache is operated transparently for end-user, and stores locally pubsub items (according to internal criteria). This is useful for many reasons: performances of course, but also it allows to do data analyse/indexing, for instance to retrieve all items with some terms (e.g.: to search by categories or hashtags). Pubsub cache is also useful to store data in a component (what is of interest for the ActivityPub gateway), or to store decrypted data (which will be of interest when we'll work on the e2e encryption with pubsub).

I'll pass the implementation details, you'll find the code on the 0.9 bookmark, notably in the pubsub cache plugin, and I've written documentation for developers for some explanations.

New commands has been added to libervia-cli to manage the cache, in particular there is a purge command to delete items according to given criteria, which will save resources and disk space. With it, it's possible to delete only certain types of items (e.g. only blog posts), for all or only some profiles (for instance, only for the AP gateway). You can say a limit (e.g. delete all items which have not been updated for 6 months). Here again, documentation has been written to explain the commands.

While doing all that, I've noticed problem to cache correctly items (because of the flexibility of XMPP Pubsub, it's hard to impossible to say if we can share cache between users), thus I've written a protoXEP (i.e. a proposition for an XMPP Extension Protocol, or XEP) to fix the problem:

I've also submitted a pull request to fix a problem in XEP-0060 (Publish-Subscribe).

While I was a working with standards, I've updated a XEP I've authored a couple of years ago to specify order of items: XEP-0413: Order-By.

Last but not least, while doing the tests for the pubsub cache I've created some helping methods (or fixtures in pytest terms) to help doing unit test.

This concludes the first step of the XMPP-ActivityPub gateway which was, as anticipated, a big one. The following steps should be done more quickly, and work on 0.8 should not be on the way anymore (I plan to publish 0.8 in early September).

That's all for this note, see you next time.


edhelas 03/08/2021, 11:08


matlag 03/08/2021, 12:50

debacle 03/08/2021, 19:56

Libervia progress note 2021-W18

goffi 06/05/2021, 11:39 jabber-xmpp-en SàT Libervia project libre Libervia progress SàT progress


again, lot of things have happened since last progress note, so I'll only talk about major changes here.

"Salut à Toi" is now "Libervia"

The project has been renamed to "Libervia". Even if I personally loved the former name (which was a reference to a French punk band song, an which could be translated to "hi to you", a nice fit for a communication tool), it proved to be hard to pronounce and remember for non French speakers, and the many names of frontends and project components were confusing. The name change has been discussed for long in the association, but the new ActivityPub/Pubsub end-to-end encryption project accelerated things: after a talk with NLnet, we decided to move forward on this so project name would not change in the middle of its development.

After doing a quick poll, we confirmed that "Libervia" (which was formerly the name of the web frontend only) would be the new name.

All parts are now named in straightforward way: "Libervia Backend", "Libervia Web", "Libervia Desktop/Mobile" (currently the same Kivy frontend for both), "Libervia TUI" and "Libervia CLI", with matching executable names (libervia-backend, libervia-web, libervia-desktop, libervia-tui, libervia-cli also aliased as li). The former names are kept internally and as aliases.

The non-profit (French "loi 1901") association behind it stays with the name "Salut à Toi".

This renaming has involved a lot for work, it took weeks to update code, web sites, doc, etc. and according to our statuses, we had to make a general assembly to discuss this decision. It's still not fully finished (notably the official web site URL is still, while is currently used for the demo server), and source code repositories have not been modified for the moment, but most of the renaming is done, and you can now reference the whole project as "Libervia"

Official Website Update

Following the changes in Libervia Web themes, the official website one has also been updated and is now based on Libervia's Web Bulma theme. The news now links to my personal blog as it is where you'll have most up-to-date informations about Libervia development (and the former page was broken). Tickets/Bug tracker is now directly accessible from the official site, as it makes more sense to have it there. It's still accessible from, and thanks to its decentralised nature, it's usable transparently on both locations.

I've also temporarily disabled account registration on the bug-tracker due a wave of spammy accounts. I will have to put in place a protection for that, but I'm reluctant to use popular non-libre options.

Flatpak and Docker

While working on the renaming and website, I've updated the Flatpaks (they were really outdated), and Docker images. Flatpaks is for now using a specific dev repos, but I hope to see Libervia on Flathub after the release.

I've created Docker images and Docker Compose file to run quickly a local demo of Libervia Web, you can see the instruction on the Official Website.

Ideally, I would like to also create Snaps, Appimages, Nix packages, etc. But I'm lacking time (Flatpak and Docker are already too much time consuming) and prefer to focus on the code rather than on the packaging, help is more than welcome though.

User Friendly URLs

As you may have noticed on the last blog posts, URLs are now more user friendly:

A blog post is referenced using its item ID, and previously a unique ID was used for that, which is relatively long and doesn't give any information about the content, but is necessary to avoid conflict (writing a blog post with an existing ID will overwrite the previous one).

To make it more pleasant, a URL friendly extension was then added, and not used to retrieve the item, so in the example above, links to the same blog post as The resulting URL is long and not easy to read, but the item is unique.

The new behaviour directly use URL friendly item IDs, and to avoid conflict, a short random suffix is appended (on the example above, QGqK is the suffix). After some tests, the collision risk for a short suffix like that is not that high (I've tested millions of IDs without collision), and it may anyway happen only if 2 blog posts have the exact same title, so the risk is very low. The resulting URL is more pleasant.

This URL friendly ID is used by default when a blog post is created, but it can be deactivated if user_friendly_id is set to false in blog post metadata, or by specifying manually an item id.

To accompany this change, a new Libervia CLI rename subcommand has been added to li blog and li pubsub, which will change the ID of an item. As there is no standard rename operation in XMPP Pubsub, this is done by copying the item to the new ID, then delete the former one in case of success.

Navigation Helpers in Libervia Web

It was not really easy so far to know where we were in Libervia Web. To help with this, the selected menu is now shown activated, and a breadcrumb has been added.

The breadcrumb is only shown when there are at least 2 elements to show (i.e. not on root pages). It is generated automatically by default, but can be customised with specific label, sub-elements, or even icons, like in the file sharing screenshot below:

Libervia Web 0.8 Breadcrumbs Screenshot

Blog Editor

As it was not possible anymore to write a new blog item with Libervia Web, I've made a blog item editor, which is relatively basic for now, but working. If JavaScript is activated, you'll get a tags editor, preview, and autosaving:

Libervia Web 0.8 Blog Editor Screenshot

File Sharing Quotas

One last missing piece I was needing before release was to put in place quotas on the file sharing component, this is now done.

Indeed, this component doesn't work with a per-file limit like most others do, but with a per-user quota, and you can upload any file size you want at long as you're not over quota.

Release to come

It's more than time to think about the release. I wanted to improve the chat notably in Libervia Web where it's still really basic since we moved out from the former frontend, but finally I've decided to report this to next release, as I plan to refactor messages handling, and for now I need to concentrate on the ActivityPub gateway.

So I'll soon prepare a beta version, and plan to do the release in a couple of weeks. I'll do bugfix on the 0.8 version during this time, but will avoid any important new development.

ActivityPub gateway project

With all the work done above (and other things, I've not mentioned everything), I've been late to start working on the ActivityPub project, but now I can focus on it. The first task is about developing a Pubsub cache as Libervia is currently getting its data for Pubsub related feature directly from the services.

Beside the obvious speed improvement, having a local cache will give the possibility to do data search/manipulation (such as doing Full-Text Search when the Pubsub service doesn't implement it, or doing feature-specific data analysis), handle message received unordered, allow to keep decrypted data when received from e2ee items, etc.

So far, SQLite was used for data storage in Libervia, by using Twisted's adbapi and custom semi-automatic schema update/data migration. It has been working relatively well so far, but it's no pleasant to maintain.

Fortunately, SQLAlchemy has recently added support for AsyncIO, thus it can now be used in Libervia. This is great, as SQLAlchemy is popular and rock solid, so I've decided to go with it. This will open the possibility to use other backends (like PostgreSQL), and refactor Libervia to use SQLAlchemy's ORM. Logically, Alembic will be used for data migration, which should make database modifications easier.

Such a cache will make possible to implements things like items discovery based on categories (or search by "hashtags" as it named in other software).

That's all for this note, see you soon.


errormovim 06/05/2021, 11:40


edhelas 06/05/2021, 11:59


matlag 06/05/2021, 13:40

debacle 06/05/2021, 14:27

ActivityPub Gateway and Pubsub e2ee

goffi 23/04/2021, 10:21 jabber-xmpp-en SàT Libervia project libre ActivityPub e2ee


it's my pleasure to announce that an ActivityPub <=> XMPP gateway doubled with Pubsub end-to-end encryption project has been selected for a grant by NLNet/NGI0 Discovery Fund (with financial support from European Commission's Next Generation Internet programme):

This big project is split in 27 steps, and will take most of my time dedicated to the Libervia project (formerly "Salut à Toi", the project has been renamed, I'll explain that in a upcoming progress note).

The XMPP <=> ActivityPub gateway will join two major open and decentralised protocols. In practice it will be a XMPP server component (usable with any server), and implement the ActivityPub server to server protocol (or "Federation Protocol"). On XMPP side, it will be mostly a Pubsub service (with some extra, like private messages converted to XMPP message stanza).

XMPP blogging (XEP-0277: Microblogging over XMPP) will be used, and thus any client supporting it will have access to ActivityPub publications (Libervia and Movim for instance).

For features present in ActivityPub and not yet in XMPP, it is planned to propose protoXEPs (i.e. proposition of XMPP extensions), to implement them. Events will also be part of the project, with a compatibility between Mobilizon and Libervia expected, and a protoXEP to have this standardised on XMPP side.

This is quite exiting, as it will extend both networks, and boost projects integrating blogging and XMPP chat.

The second part of the project is about end-to-end encryption. XMPP has enjoyed major improvements on end-to-end encryption following the work done on OMEMO, notably initiated with Conversations, and on OX, modern OpenPGP integration. This is great, but has been so far mainly focusing on instant messaging. The goal will be here to add end-to-end encryption to XMPP Pubsub, which includes protoXEPs and implementation in Libervia. In other terms, at the end of this project, it will be possible to use e2ee with all Pubsub based features (like blogs, forums, lists, or events that you can do on Libervia), this is huge! Signing will be part of the project too, meaning that it will be possible to authenticate something like a blog post in a standardised way.

Beside the standards which will benefit to the whole XMPP community, all of this will be implemented in Libervia, this include updating current implementation to the state of the art (i.e. updating current OMEMO implementation and implementing OX).

Last part of the project will be the implementation of e2ee in the web frontend. Due to Libervia specific architecture, OMEMO is not currently usable from the browser (the implementation is done on the backend). To make this possible, the Python OMEMO library which is currently used will be ported to WebAssembly and Brython, allowing to do encryption and decryption directly within the browser.

As you can see this is massive. I'll do most of this but I won't be alone (notably the author of Python OMEMO will do the wasm/Brython port as part of the project). The project should last circa one year, with the ActivityPub <=> XMPP gateway being the first part worked on.

I would like to thanks again NLNet and EU's NGI for allowing this, and my employer (Sourcefabric, which notably develops Superdesk) for letting me adapt my working schedule.

I've adapted the tasks to Libervia's (XMPP powered) bug tracker, so you can see step details and follow progress there:

Also I'll continue to publish progress notes so stay tuned to this blog (that should be available also on ActivityPub later this year ;) ). The website has been updated, with new Flatpak and Docker installations, check

If you have questions or comments, feel free to join Libervia's XMPP room at or to contact me for instance via ActivityPub (

See you soon.

debacle 23/04/2021, 18:57


errormovim 06/05/2021, 11:13


sthaan 14/11/2021, 19:20

SàT progress note 2020-W53

goffi 03/01/2021, 17:09 jabber-xmpp-en SàT project libre SàT progress

Happy New Year!

It's been a long time since the last progress note, and things have been moving.

First my apologizes for not releasing SàT 0.8 at the end of 2020 like I was expecting: I'm willing to polish some features before releasing, notably in Libervia (web frontend), and I thought that it was best to wait a few more months. I'll try to release more often in the future.

Let's have a high level overview of what has been done since last progress note.


I've been working on Libervia UX for invitations. SàT implements an invitation system to easily share an activity (photo album, event, or anything). Here "sharing" means sending a notification, and giving access to somebody. The invitation can be sent to somebody in your contact list by entering some letter of his/her name, somebody external by providing the full jid, or somebody without XMPP account by sending an invitation by email. It's only a few click, and access can be removed just by clicking on the deletion cross. I believe that this is a major feature to use easily this as a familial social network.

Photo album invitation in Libervia

Docker integration

You're probably wondering what Docker has to do with an XMPP client (installation put aside). Well, the are several reasons why it's really useful, the first one is to integrate third party software into frontends like Libervia.

As you may know, we are dogfooding most of the development tools with SàT and XMPP (things like tickets/bugs reports are managed with it). So far, there was no translation application used, and translations were done using desktop apps like Gtranslator, which is good but not so easy to install for contributors. With the new Docker integration, Weblate can be added in Libervia with just the following setting in sat.conf:

menu_extra_json = [

With this simple setting, a new "translate" menu will appear in Libervia and Weblate will be there:

Weblate integrated in Libervia via Docker

The application needs to be integrated with SàT, this is done in a YAML file: here the official Weblate Docker image is used, and SàT settings are re-used when possible to make the process as easy as possible (for instance the configuration to send email is re-used automatically). Note that Docker is currently used, but the plugin managing this is made in such a way that other tools can be used in the future (maybe LXC, systemd-nspawn, Python's virtual envs or something else).

For now it is "weak" integration, Weblate has its own accounts/login. If one day we have the resources, it would be great to work on deeper integration with single log-in (and maybe contributing XMPP login upstream), and a theme adapted to Libervia's one.

An other application I plan to integrate this way is Jitsi Meet: at the moment I have not the time to work on video conference, and Jitsi is really good, handles multi users calls, and uses XMPP too. Integration of Jitsi is a good way to have video conferences quickly in Libervia, until it's possible to find the time to do a native implementation.

End to end tests

The second reason why Docker integration was useful is for end-to-end tests. Historically SàT has been tested with Twisted's trial tools, and there was a Buildbot installation. But with time and lack of resource, this has been unmaintained, and it would have been lot of work to put that back in shape.

Thus I've restarted fresh and I'm now using the popular pytest framework. I've decided to focus on end-to-end tests as it's a way to check the whole ecosystem (including SàT PubSub). For now, tests are done with "jp" (the CLI frontend) and Libervia. For the former the sh module is used with the help of pytest's fixtures, this way tests are really easy to write. For Libervia, I've gone with Helium which is a high level module to use Selenium. The only worry I have is that I'm not sure if Helium will be maintained on the long run, but it should not be a big deal to switch if necessary, and it makes some things easier (notably drag and drop simulation).

Above that there is a little script to make it easy to run the tests, with an option to launch a VNC viewer to follow Libervia tests in real time (check documentation for details). I have long term plan to integrate that in Libervia next the to the source code, in a way similar as what you may see on popular code forges (like Gitlab).

That was also the occasion to rework SàT and Libervia's Docker images. There is still some polishing and documentation to do, but it should be fine for the release.

Full-Text Search for PubSub

One of the last major feature I wanted to implement before the release is Full-Text Search in PubSub. This is using the namespace specified in XEP-0431 and implementation is done in SàT PubSub (the generic PubSub component developed in parallel of SàT to be sure to have all needed features). You can see the result on this blog with the new "search" bar.

the new search box use PubSub Full Text Search

PostgreSQL's FTS engine is used, and it is possible to specify the language of the content. For instance if a blog is known to be in English, you can set the fts_language setting of the node to english. This is needed for improved results because it lets PostgreSQL use the right canonical form of the word. The canonical form of a word is a common root used for variations (like singular/plural, or verb conjugation). Thanks to this, the search will return articles which contain progress note in this blog, even if you search for progresses in plural form.

By default a generic language is used (which correspond to PostgreSQL's simple dictionary), which works with everything but has lower results.

The implementation has been thought to make it possible to override the language used per PubSub item (but it is not yet used). This will be useful for multilingual pubsub nodes like this blog (which is written in French and in English).

The neat thing with having that in PubSub is that it is now available out of the box for all PubSub based feature. So Full-Text Search is now also available in ticket handlers too (like SàT's bug tracker).

SàT advanced features are now usable with generic PubSub services

For features like tickets handlers or merge requests, a SàT PubSub specific implementation has been initially done to manage "Node Schema", i.e. a way to attach a data form template to a node (to indicate how data are organised, and to reject invalid items).

After announcing the ticket feature years ago, I've got a message mentioning XEP-0346 which I've missed at the time. This XEP has the advantages to work without modification on a generic PubSub service. It is now implemented in SàT and SàT PubSub, and thus all features should work with any standard implementation of PubSub. SàT PubSub is still recommended though, as it implements features like Order-By or serial ids which improve user experience and are rare or nonexistent at the moment in other implementations.

many other things

I won't list all the things done since last progress note since there are too many. But in brief, I can tell that XEP-0353: Jingle Message Initiation has been implemented, this is useful to send a file using a bare jid and improves UX a lot, thumbnails of videos are generated (notably useful for photo album), a loading screen is now shown in Libervia to avoid unresponsive actions if JavaScript is not fully loaded, there are new jp commands, bug fixes, etc.

Anyway it's enough for this time, see you soon.

debacle 04/01/2021, 20:48

SàT progress note 2020-W31

goffi 02/08/2020, 20:25 jabber-xmpp-en SàT project libre SàT progress

Hello, it's time for a summer progress note.

Libervia has seen a major UI revamp with a new theme based on Bulma CSS framework.

I've been hesitating for long to use a CSS framework, and the default theme has been home made with CSS classes following BEM naming convention. On the paper it's nice because you can easily extend it without breaking accidentally other components/pages, but in practice that was more work for a not so great result regarding the UI. It could become nice with time and efforts, but I'm desperately lacking time, and I rather put my efforts on other things.

So I've decided to work on theming and try the Bulma framework, on which I was keeping an eye for a little while. I was so far quite reluctant to use super popular CSS frameworks, because we tend to end with all websites looking the same, but I have to admit that using one save a LOT of time, and the result is clean and good looking with little effort.

Here is a screenshot of the forum page with the new theme:

new "bulma" theme in Libervia

Last time I've explained how I have implemented dynamic part of Libervia with Brython. This is now completed by the use of Nunjucks for dynamic templating. The goal is to have the same templates in the backend and in the browser, and Nunjucks is more or less compatible with Jinja2. I say "more or less" because some features, filters or extensions are missing. To work around that, I've implemented myself missing filters (xmlattr for instance), or a way to parse keyword arguments with Nunjucks convention. Nunjucks doesn't handle kwargs in macros so I've add to rewrite macros where it was used. The most tricky part was the use of i18n extension: Nunjucks doesn't have it, and thus it was failing when reaching a {% trans %} tag. I've had to implement an extension myself, but for now it doesn't translate and just returns the string unmodified.

Finally, it's working quite well, and the same templates can be used for static (backend) and dynamic (in browser) parts. This is particularly useful when you're doing a website which can be used without JavaScript, and which is enhanced when JavaScript is activated.

I've implemented server part of HTTP File Upload in the file sharing component included with SàT. This way you can see all files uploaded (with SàT or any other XMPP client) in your uploads directory, and you can delete them, which is something I was badly missing from current ecosystem.

Deletion is currently done using Ad-Hoc Commands, but I'm planning to move at some point to a PubSub based file sharing which would give all we need to manage correctly deletion or notifications. There is some work to do on the standards first, that's why I haven't done it from the beginning.

In addition to the ability to delete files, there is no upload limit with SàT file sharing component. Instead there will be a quota system (not implemented yet).

Some import mechanism should come soon, at least to import files uploaded on Prosody HTTP Upload, so the switch to SàT file sharing component will be easy.

I've put some efforts on the photo album, the goal is to have something simple and straightforward to use, working well on desktop or mobiles platforms, with or without touchscreen. There is a permission system to indicate who can view the pictures. From Libervia, pictures are currently uploaded with HTTP Upload (with some specific headers to indicate the path of the albums), until I have time to implement Jingle with WebRTC (maybe in next version?).

Here is a screenshot of the photo album with the new theme:

photo album in Libervia with "bulma" theme

I'm currently putting my effort to make SàT/Libervia a good fit for sharing with family or close friends, little communities or small team. In other words a familial social network.

If everything goes well, I have good hopes to go beta in August and release 0.8 somewhere in September.

That's all for this note! As usual, feedbacks are welcome.


edhelas 02/08/2020, 21:24

debacle 04/08/2020, 17:41


vince 02/11/2020, 15:41

Ayo, very nice work! Is it already available in some community? We'd like to understand more!

SàT progress note 2020-W21

goffi 20/05/2020, 10:23 jabber-xmpp-en SàT project libre SàT progress

Hello everybody,

during the last few weeks, I've been focusing on Libervia (web): I've been working on the management of dynamism, or in other words the integration of JavaScript and browser side Python with the Libervia web framework.

If you're wondering what I mean by "browser side Python", let me explain briefly some history of Libervia: the former version of this web frontend was a single page application made with Pyjamas, a framework more a less similar to GWT but with Python instead of Java. The main reasons of this choice was to avoid constantly moving from 2 different programming platforms (Python and JavaScript), to factorise code with other frontends, and to avoid the JavaScript ecosystem which is constantly moving (resulting in lot of time spent in following the evolutions, learning new frameworks, rewriting code, etc.).

Pyjamas was made of 2 main parts: a Python to JavaScript transpiler, and a set of libraries to write a web site in a way similar to a desktop application. This was working reasonably well, and once past the initial big download, the application was working nicely. We could indeed factorise code with other frontends, and save time and maintenance efforts.

With time, we realised that hiding the abstraction of the web development to make it look like desktop was not so great: since the beginning of Libervia, the web ecosystem had improved greatly (HTML 5 and CSS things like flexbox notably), and it was getting hard to use the novelties. The application was not responsive and unusable on mobile, while phone was getting the main platform for many people.

In addition, 2 major issues were resulting in a dead end for Pyjamas: first a hijack of the project (not just hostile fork, but true hijack: the official website has been redirected to the fork named pyjs without the consent of the main contributor of Pyjamas, and the mailing list has been redirected without the consent of its subscribers), and second Pyjamas was stuck with Python 2, and a Python 3 port would mean a nearly full rewrite.

So we decided to move away, and the result was Libervia Pages, i.e. the framework made to integrate XMPP, Python, and web. For SàT 0.7 the first goal was to have a static or nearly static framework, with minimal JavaScript, and to implement dynamic part for 0.8.

The decision was to keep Python in the browser, for the same reason that initially lead to Pyjamas, but this time with the possibility to change the "engine", i.e. the software allowing to do Python in the browser. So we keep the door open to use only JavaScript if in the future we decide to move to something like Vue.js or React.

We have been carefully checking the various options, and our favorite candidates were Brython and Transcrypt.

Transcrypt is a Python to JavaScript transpiler, pretty similar to what was doing the transpiler of Pyjamas. It has the advantage of staying close to JavaScript, keeping its speed, and has a system to activate/deactivate Python compatibility features depending on the needs (better compatibility may mean lower performances).

Brython on the other hand is doing the transpilation in the browser, it is like having a Python interpreter in the browser. Its has some decisive (for us) advantages: full Python compatibility, and the possibility to dynamically convert Python to JS. The Python compatibility is essential to factorise the code with other frontends, and the ability to convert Python to JS open the way for future use (like sharing code during a chat, e.g. for a school or scientific use). I've been following the Brython community for years, it is really friendly and dynamic, and the few issues I've reported online were addressed quickly.

So Brython has been chosen as the main way to do dynamic code in the Libervia web framework, but it is possible to switch to something else. To use it, it is as simple as writing some Python in a file in a _browser directory of a page ; Libervia will take care of installing Brython, copying and loading the script.

As an example, here is how you would show an alert if somebody click on an element with author class:

from browser import bind,alert

@bind(".author", "click")
def click(ev):
    alert("click on an author")

As we want to have dynamism used progressively (i.e. the page works without JavaScript, but enhancement happen if JavaScript is activated), it's really straightforward to work this way, while it is still possible to do more complex code for fully dynamic pages (like it will be the case for the chat).

Beside Python, JavaScript ecosystem been integrated through the use of either yarn or npm (whichever is present on the system). A common JSON file is used to indicate dependencies (using the syntax of package.json well known by frontend developers), and potentially how to generate corresponding Brython module. Sass has been integrated too.

I've also worked on themes, but I don't want to make this blog post too long to write and read, so I'll talk about that next time.

debacle 22/05/2020, 21:51