Know what you own.
Measured, not guessed.
Nodian Audio is a local music library. Point it at folders of audio and it measures every file — loudness, tempo, musical key, an energy rank, a waveform — reads the tags already inside them, and gives you a browser to audition, rate, cue and mix from. It runs entirely on your machine: nothing is uploaded, and no file is changed unless you ask.
Two parts, and you need both
Audio comes in two pieces, the same way Studio does. The desktop app is the window, and it starts the runtime for you. The runtime is what holds your library: it reads your files, does the measuring, and answers on 127.0.0.1:8770. Install it whichever way you use Audio — the web app at audio.nodian.directory connects to that same local runtime, never to a server of ours.
Download the desktop app
The desktop app is the same Audio that runs at audio.nodian.directory, in its own window — plus the one thing a browser tab cannot do: start the local runtime. It still needs the runtime below; when it cannot find one it tells you where it looked and offers to locate it.
Not code-signed yet, so Windows SmartScreen will warn that the publisher is unknown. Click "More info", then "Run anyway". The file installs for your user only, with no admin rights.
SHA-256 8b29dff35280c48c1a99cae6122d49c6d22ffa4764bf4e4e6ca356120716d3cd
Verify the download with "certutil -hashfile <file> SHA256" and compare it against the checksum above (also published in SHA256SUMS). SHA256SUMS
Install the runtime
The library itself: Python and ffmpeg, with no bundled interpreter, which is why it is under half a megabyte. Extract the zip and install its two dependencies — numpy and scipy. Everything else it uses is the Python standard library or ffmpeg.
Extract the zip, open a terminal in that folder, and run:
pip install -r requirements.txtSHA-256 7d3aab78bb461e2274a89331941073a471039ef6261752815d1ca791bc1817fc
Verify the download with "certutil -hashfile <file> SHA256" and compare it against the checksum above (also published in SHA256SUMS). SHA256SUMS
What the runtime needs
The runtime is Python, so it is not Windows-only the way the desktop app is. The installer above is Windows; the runtime runs on macOS too.
Optional: stem separation and VST hosting are paid add-ons with their own separate install; the app reports why one is unavailable instead of failing halfway.
Install in four steps
Download and extract
Use the runtime button above, and extract the archive wherever you want your library to live.
Install the dependencies
Run the command above inside the extracted folder. It installs numpy and scipy; make sure ffmpeg is on your PATH as well.
Point it at your music
Run "python tracks.py sources --add" once per folder you want it to watch, then "python tracks.py scan" to measure them. This step is not optional: the runtime refuses to start on an empty library.
Serve it
Run "python tracks.py serve". The library answers on 127.0.0.1:8770 — open the desktop app, or go to audio.nodian.directory and let it connect.
What it does
Measured, not guessed
Loudness is BS.1770-4 with the K-weighting and both gates, not an RMS approximation. Tempo is spectral flux, autocorrelated, with a prior that resolves the octave. Key is Krumhansl-Schmuckler over a chromagram — and it ships with a confidence, because on ambient material key detection is a guess, and a number without a confidence invites decisions it cannot support.
Your masters are never touched
A level, an EQ curve, a trim, a cue — all stored beside the audio and applied at render. The one command that writes into a file is opt-in per run, verifies the result before replacing anything, and refuses formats whose tag container no DJ software reads.
Split three ways, so search works
Free-text style blobs are separated into genre, vibe and instruments on ingest, so "deep" the mood and "deep house" the genre stop being the same token. Embedded ID3, Vorbis and MP4 tags are read through ffprobe. Search then runs across title, artist, genre, vibe and key.
Or use it in a browser
audio.nodian.directory is the same app as a web page. It is static and carries nothing secret — the library it talks to is the runtime on your own machine, at an address you choose. Install the runtime first; the page's connect screen waits for it.
Open audio.nodian.directoryReady to install?
The desktop app is Windows today. The runtime runs on Windows and macOS. Both files are below.
Neither file is code-signed yet, so Windows will warn about an unknown publisher. Both are published with SHA-256 checksums you can verify.