Amarula - a WhatsApp client in pure Elixir

Hi all, I’m posting a new thread for Amarula as the original went off topic and the mods have suggested I create a new one with that feedback in mind.

Amarula is an unofficial WhatsApp client written in Elixir. It’s a port of the JS library Baileys, and it speaks the real protocol end to end. It’s no wrapper over another runtime: you receive messages as events in a process/GenServer of your choosing, and can run multiple connections side by side, each in its own supervision tree.

So in v0.5.0 you get:

• QR-code, phone-pairing, credential persistence;
• Send/receive text, media, reactions, and more, in 1:1 and group chats;
• Pluggable Storage;
• quick start via mix task to pair a device;
• multiple parallel devices;

I tried to keep its deps as lean as possible, and implemented community feedback to keep it less intrusive and more flexible. I’ve also been looking at references of the same implementation in other languages for bugs and issues, trying to reproduce them here, and I’m hopeful to get your feedback to make it better.

Noise and Signal (double-ratchet E2E) are implemented in Elixir, with the primitives (AES-GCM, X25519, SHA) backed by Erlang’s :crypto. The one exception is XEdDSA signing, which is written in Elixir and not constant-time, so it’s a faithful protocol port, but that signing path isn’t hardened against timing attacks.

Two important warnings:

1. This is an unofficial WhatsApp client, not endorsed in any way by Meta. Use it knowing Meta may ban your number (with no warning and no appeal) so only use an account you can afford to lose.
2. The whole thing was vibe-coded, and this is explicit in the commits and PRs.

I’ve been having quite a lot of fun building it. I’m curious what the community will use it for.
All feedback is quite welcome!