AURA

Audio Unified Rust Architecture
(DE-Gag: AUdio RAhmenwerk)

CLAP-first plugin framework for LX Audiolabs.
Partner tooling: agal (agent orientation) · this repo (runtime + formats + build + CLI).

License: GPL-3.0-or-later — see docs/licensing-compliance.md.

Layer	Name
Product	AURA
Crates	aura-*
Umbrella	aura → use aura::*
CLI package	cargo-aura
Invoke	cargo aura … (e.g. cargo aura new, cargo aura build --clap -plug <crate> [<crate>...])
Config	aura.toml

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Scope (hard)

AURA is intentionally narrow. If that is not your stack, use something else — no hard feelings.

We commit to	We do not ship
UI: Slint only, via aura-baseview (+ aura-editor host adapter)	egui, iced, Vizia as first-class UIs
Formats: CLAP primary; VST3 / LV2 only on the OS cells below	Audio Units (AU), AAX, VST2; “every format everywhere”
Hosts: Bitwig-first, then REAPER and other real CLAP/VST3/LV2 hosts	Pro Tools / Logic-only AU pipelines as a goal; Wine workarounds as product path
Platforms: Windows, Linux, macOS	iOS / embedded plugin hosts in v1

Slint + baseview (always)

• Always: Slint UI + baseview host window (embed, scale, keys, clipboard, …).
• Choose renderer (features / project config), not toolkit:
  • FemtoVG (OpenGL) — default
  • Skia — optional
  • Software / wgpu blit — optional
• There is no “raw egui editor” mode and no second UI framework in AURA.

That stack is aura-baseview (window/renderer) + aura-editor (host adapter) + aura-build (compile-time). Every AURA plugin UI goes through it — not an optional addon.

CLAP first (formats)

Same hardness as Slint: we pick a primary path and refuse a kitchen-sink matrix.

• CLAP is the better plugin format for what we build — modern, open, one native path on Linux, Windows, and macOS. That is the motto and the default (cargo aura new, CI validator, Bitwig-first host smoke).
• VST3 is a pragmatic second path where the host world actually needs it: Windows and macOS only. Linux VST3 often means Wine or other heavy hacks — we do not treat that as a supported ship path.
• LV2 is a Linux-native path (process/params/state/UI where the ecosystem fits). Not a Windows UI story; not a macOS story (rust-lv2 / host reality).

Ship matrix (what CI installs / what we call a supported host path):

Format	Linux	Windows	macOS	Role
CLAP	yes	yes	yes	Primary — always
VST3	—	yes	yes	Secondary — Win/mac hosts
LV2	yes	—	—	Secondary — Linux

Wrappers may still compile on other OSes for unit tests; product support is the table above — just as “Slint only” does not mean “optional egui if you flip a feature.”

Looking for egui, iced, AU, or every-format-everywhere?

AURA is not the right framework. Please use other open source projects that already optimize for that:

Need	Go here
Flexible Rust plugins, egui / iced / multiple UI styles, broad format matrix	nice-plug (NIH-plug successor)
CLAP-centric Rust ecosystem / lower-level CLAP work	clack (and related CLAP crates)
Full multi-format framework including AU/AAX paths, egui/iced/Vizia options	truce · truce.audio

We stand on the shoulders of that work (and permissive crates like CLAP bindings). AURA exists so LX can own a Slint + baseview + CLAP-first line — with thin VST3/LV2 where the OS and hosts justify them — without carrying every UI toolkit and every legacy format.

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Design principles

1. Slint + baseview only — renderer is a backend choice (FemtoVG / Skia / software); toolkit is not.
2. CLAP first, thin formats — one plugin logic API; VST3/LV2 only on the ship matrix; no format-shaped core.
3. Framework layout — crates/ · examples/ · tools/ (product catalogs keep their own plugins/ outside AURA).
4. One CLI: cargo aura — parity with cargo truce (new, build, install, doctor).
5. KISS for humans and agents — aura.toml, boring paths; orientation in agal.

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License

Copyright © 2026 LX Audiolabs

This project is free software under the GNU General Public License v3.0 or later.
Distributing plugins that link AURA implies GPL obligations for that combined work. Selling with source is fine; closed-only ships are not the goal.

Third-party notes (including Slint triple license — default ship path GPLv3):
docs/licensing-compliance.md.