Show HN: Audionaut - an open-source cross-platform multitrack audio editor

Overview

Audionaut is a free, open-source desktop application for effortless audio editing and recording. Whether you're working on music, podcasts, or multitrack recordings, it gives you precise cutting, per-track playlists, flexible multi-channel support, and clean exports - without the weight and complexity of a full DAW. Audionaut is written in modern C++ on the JUCE framework and runs natively on Windows, macOS, and Linux.

AI Agent Integration (MCP)

Audionaut speaks MCP, so Claude and other agents can edit your sessions. With the app and Node.js 18+ installed:

claude mcp add audionaut -- npx -y audionaut-mcp

Keep the project open in Audionaut and each edit arrives as one undo step. On macOS, keep projects in your Music folder. Claude Desktop setup and details: manual, chapter 11.

Make sure to clone with submodules:

git clone --recursive https://github.com/kvoltmer/Audionaut.git

or once cloned do:

git submodule update --init --recursive

Analysis Features (Essentia)

The analysis features (BIC segmentation, onset detection, beat tracking) link against a static build of the Essentia submodule. Build it once after checking out the submodules:

./Audionaut/Builds/build_essentia.sh

The script builds Essentia's 3rd-party dependencies statically (slow, skipped on re-runs; force with FORCE_3RDPARTY=1), then configures and builds Essentia itself with its waf build system into Submodules/essentia/build. It patches Essentia's Linux-oriented 3rd-party build scripts in the working tree as needed for macOS/Apple Silicon, so the essentia submodule will show as dirty afterwards - don't commit those changes.

Prerequisites:

• Python ≤ 3.11 - Essentia's bundled waf needs distutils, removed in Python 3.12. The script picks a suitable interpreter automatically; override with PYTHON=... ./Audionaut/Builds/build_essentia.sh.
• pkg-config (e.g. brew install pkg-config)
• CMake 3.x recommended - some 3rd-party deps ship very old CMakeLists that CMake 4.x refuses (e.g. pip install "cmake~=3.31.0").

Building Essentia is optional: without it, ESSENTIA_ENABLED auto-detects off and the app and tests compile with the analysis features disabled.

Stem Separation

Stem separation runs demucs.cpp, a C++ port of Meta's Demucs, compiled straight from the Submodules/demucs.cpp submodule - no separate build step. It needs the submodule's vendored Eigen (Submodules/demucs.cpp/vendor/eigen, a nested submodule that --recursive fetches); the CMake build detects it and sets AUDIONAUT_ENABLE_DEMUCS accordingly. The model weights are not in the repository: the app downloads them on first use into its Models folder, or point the CLI at a copy with --model.

Building the Application

Xcode - open the Xcode project located here: Audionaut/Builds/MacOSX/Audionaut.xcodeproj

Visual Studio 2026 - open the Visual Studio solution located here: Audionaut/Builds/VisualStudio2026/Audionaut.sln

Linux Makefile - install dependencies:

sudo apt install libasound2-dev libjack-jackd2-dev ladspa-sdk libcurl4-openssl-dev libfreetype-dev libfontconfig1-dev libx11-dev libxcomposite-dev libxcursor-dev libxext-dev libxinerama-dev libxrandr-dev libxrender-dev libwebkit2gtk-4.1-dev libglu1-mesa-dev mesa-common-dev libxi-dev libegl-dev

then compile:

cd Audionaut/Builds/LinuxMakefile/
make CONFIG=Release -j8

See the Catch2 tests README.

Command-Line Interface (audionaut-cli)

audionaut-cli gives scripts, CI and AI agents headless access to .audium projects - no GUI, no audio device. It builds alongside the tests:

cmake -B build -S Audionaut/Catch2Tests
cmake --build build -j8 --target AudionautCli
./build/AudionautCli_artefacts/AudionautCli --help

Every command takes --json to emit exactly one machine-readable result envelope on stdout ({"ok": true, "result": ...} or {"ok": false, "error": ...}) with all logging on stderr, plus --quiet. Exit codes: 0 success, 1 operation failed, 2 usage error, 3 feature unavailable in this build (e.g. analyze without Essentia). Option values may be given as --opt value or --opt=value.

Examples:

audionaut-cli create song.audium --channels 2
audionaut-cli import song.audium take1.wav take2.wav --position 4.5
audionaut-cli info song.audium --json
audionaut-cli analyze song.audium --types sbic,beat_degara
audionaut-cli auto-edit song.audium --track 0 --measures 4
audionaut-cli assemble song.audium --duration 60 --mode random
audionaut-cli split song.audium --at 23 # bar 23; --unit beats|seconds|clocks
audionaut-cli create-region song.audium --name chorus --start 17 --end 25
audionaut-cli set-region song.audium --region chorus --rename drop --length 8
audionaut-cli place-clip song.audium --region drop --at 33
audionaut-cli move-clip song.audium --region drop --to 41
audionaut-cli remove-clip song.audium --at 41 --track 0
audionaut-cli clip-gain song.audium --region drop --gain -6 --db
audionaut-cli clip-fades song.audium --region drop --fade-in 1 --fade-out 2 --unit beats
audionaut-cli separate song.audium --track 1 # Drums/Bass/Other/Vocals tracks; needs the Demucs model
audionaut-cli export song.audium -o mix.wav --sample-rate 48000 --bit-depth 24

A typical agent flow: create → import → analyze → auto-edit /assemble → export, checking ok in each --json envelope. Projects written by the CLI open in the GUI app and vice versa. End-user documentation lives in the User Manual.

Analytics

CLI invocations report anonymous usage statistics under the same strictly opt-in consent as the app (one cli_command event: verb and exit code) - nothing is sent unless consent was granted in the app's settings. Set AUDIONAUT_DISABLE_ANALYTICS=1 to switch the CLI's reporting off regardless (CI environments, scripts).

Application Usage

The main Audionaut app also accepts the same verbs (Projucer-style): run the app binary with a verb and it executes