Libwa: WhatsApp C Library | Hacker News Reader

Libwa: WhatsApp C Library

github.com

84 pointskeepamovin19 comments

Author here. I haven't used in years so is probably pretty broken. There is a "wire" branch that implemented some debugging of the different encapsulation layers in a plain text format.

Also, last time I was using it I needed to use a throwaway number as WhatsApp was detecting and banning anything that resembled a non-official client.

This may (finally) change with the Digital Markets Act [1][2] in Europe, but sounds too good to be true.

[1]: https://digital-markets-act.ec.europa.eu/index_en

[2]: https://techcrunch.com/2023/09/11/whatsapp-has-started-work-...

Whatsapp did a revamp of their web client a few years ago.

The previous version pretty much connected to your phone and proxied all send/receive message requests via your phone. The phone stored all the crypto keys etc for e2e.

The new version acts as a fully fledged client. All "1:1" chats are in fact group chats, containing multiple 'users' for all of your devices, and multiple users for all of the other persons devices. Cryptography is still e2e secure, but now there are n+m endpoints for all of your+their devices.

Therefore, I would expect major updates to be needed to this client to make it continue to work.

> All 1:1 chats are in fact group chats, containing multiple “users” for all your devices

Wow, that’s a really interesting way to see it I hadn’t heard before. It works remarkably well, too.

That’s the “0, 1, infinity” principal.

A more recently updated, and definitely working library : https://github.com/tulir/whatsmeow

Sidenote: it is not developed in C, but with Go

This hasn’t been updated since 2019 which is long before WhatsApp made substantial changes around multi device usage. This is almost certain to be broken.

Devil's advocate (and as a very lightweight Whatsapp user), is this just based on a scrape/listen of how whatsapp currently works, so maybe prone to breaking?

Pessimistically any bit of code can scrape a present day service, is this easily maintanable, how often will it break, maybe permanently?

That said, fair play for sharing in the open, just querying the long term efficacy of using it.

Unless using an official API, things can be a bit brittle.

I've been using a Matrix bridge for WhatsApp for a couple of years, and rarely bother updating the container. I don't think I've ever run into an API deprecation issue.

Perhaps there are implementation differences between this and the Go library underlying the Matrix bridge, but I don't think API incompatibilities should be a concern.

Does anyone know if its possible to collect all images that were posted in a whatsapp group, given one group members login/credentials?

I believe you can do this without much of a hassle if your phone is rooted. But to root your phone you need to unlock the bootloader which will clear all the data. You could also probably write a script and grab using the web client? I'm not sure if you have full history and just trying to be helpful. Use better advice if it comes by.

You can Syncthing / FolderSync all images from any Android phone. However, I am still looking for a way to access my own chat data to link which image belongs to which group.

Google Photos will back it up if you so choose.

What's a good use case for this library? Something that needs to send messages from an embedded system?

If you want to send whatsapp messages from a RPi, you basically can't do it today (since the only working implementations today require a headless Chromium instance, and good luck fitting that into 512M of RAM).

With zram that’s more like 1.5gb, so doesn’t seem too impossible.

What about https://github.com/tulir/whatsmeow?

Last commit in 2019, I wouldn't expect it to work. And why would this specific library be interesting?

The intention is good, but they will try to break it as much as they can.

The only way to robustely deal with those "people" is to go thru extremely aggressive technical regulation: enforce a small and simple, but good enough, very stable in time network protocol support for the client.

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