OpenNord

An open companion for Nord® keyboards — starting with the Nord Stage line. Read and organize your programs, play your samples on-screen or from a MIDI keyboard, and talk to your Nord directly over USB — no desktop app required.

Status: early — the reverse-engineering is done, the product is being built. OpenNord is family-wide by design: one shared file container and one shared USB transport run the whole Nord line (src/lib/clavia/ carries a full-line model registry). The Nord Stage series comes first — Stage 2 / 3 / 4 files read today, and Stage 4 is decoded and validated (0-mismatch against ns4decode) with its USB transfer protocol reverse-engineered and hardware-validated both ways (enumerate, read, and write — on a real device). Other families (Electro, Piano, Lead, …) are mapped and next. What remains is the product layer — UI, community sharing, AI.

[!WARNING] Beta software — use at your own risk. OpenNord is under active development, provided as-is, with no warranty (see the AGPL-3.0, sections 15–16). Things will change and break. Most of all: device transfer writes to real hardware. Writing a program to your Nord overwrites whatever was in that slot — back up your keyboard first and don't run it on data you can't afford to lose. You are responsible for what you send to your instrument.

Documentation: how to use OpenNord and how to work on it is at opennord.gigmeister.app/docs, built from the Markdown in docs-site/ (Astro Starlight; cd docs-site && npm install && npm run dev).

OpenNord is free and open source (AGPL-3.0). It exists because everything that makes it possible — the Nord file-format knowledge, the decoders — was built by the community, in the open. This gives that work a home that outlives any one person and a place for the next contributor to plug in.

What it does today

• Read a program. Drop a Stage 2 / 3 / 4 file (.ns2p / .ns3f / .ns4p) and see what's inside — piano/sample, organ, synth, effects. No keyboard or Sound Manager needed. Every Nord generation shares the same CBIN container, so reading runs through one model-codec registry built to extend across the family.
• Organize a library. Point OpenNord at a folder (or import single files) and it builds a searchable, mobile-first Library — the home screen — split into Programs · Samples · Presets with a master/detail view. Search today is a zero-config keyword ranker (an LLM ranker drops in behind the same interface).
• Play your samples. The sample workshop reads .nsmp/.nsmp3/.nsmp4 — keyboard map, loop points, root notes — and lets you audition them on an on-screen keyboard, or (desktop) play them from a MIDI controller: a lightweight rompler — pitched, polyphonic, velocity + sustain — for testing sounds with no Nord plugged in. Convert across generations, and export any sample to WAV (or all, to a zip). Imported .nsmp samples persist as your own local sample library.
• Talk to your Nord. Pull programs off the keyboard and write them back over a reverse-engineered USB protocol, proven on real hardware — a vendor bulk protocol, not MIDI SysEx. A read-only "Check my Nord" probe enumerates any connected Clavia device and reports what OpenNord supports. Transfer is desktop (WebUSB / node-usb) and native iPad (M1+, DriverKit) only — iPhone and PWAs can't reach vendor USB.

Community patch sharing and AI (explain a patch, or generate one from a description) are designed but not built yet.

Desktop app

There is a desktop app for macOS and Windows on the Releases page. It exists to reach the older Nords a browser cannot connect to (electron/README.md).

What the installers contain. They are built from this repository, plus OpenNord's community client: browsing and previewing sounds other players have shared. That client is not part of the AGPL source here. It is off until you turn it on from the Community page, and until then the app contacts no server for it; turned on, it only reads public pages, and nothing from your Nord or your library is sent. Building from this repository (npm run electron:pack) gives the app without it.

Why it can exist

A lot was already done — see ATTRIBUTION.md. The Stage 2/3 format is openly documented (ns3-program-viewer) and the Stage 4 format was partially decoded (ns4decode). OpenNord builds on that and adds what didn't exist: Stage 4 transfer to a current Nord (the USB protocol, reverse-engineered here), combined with open parsing, a mobile-first library, and sample playback in one tool.

Quickstart

npm install
npm run dev          # web app
npm test             # parser/decoder tests (vitest)
npm run typecheck    # tsc --noEmit  ┐
npm run lint         # eslint + stylelint ┘ CI gates — keep both green
npm run build        # production build
npm run fixtures:scan # check real files: fixtures/<model>/ and/or NORD_FILES=~/Music/Nord (see fixtures/README.md)
npm run cap:sync     # wrap for iOS (Capacitor) once you add the ios/ platform

Working in this repo with an AI agent? See the maintainers’ notes for the decode-layer map, commands, and the legal guardrails.

Layout

Path	What
src/lib/clavia/	the shared, model-agnostic layer: CBIN container, checksum, name/slot/category, the file identifier + ModelCodec registry
src/lib/ns4/	the Stage 4 .ns4p body codec — model + parser + bit/byte decode (decoded + validated, the heart)
src/lib/ns3/, src/lib/ns2/	Stage 3 / Stage 2 body decoders + factory-library catalogs (multi-model, the maintainers’ notes)
src/lib/device/	WebUSB device layer — transport → session → transfer (read/write), backup, hardware probe
src/lib/folder/	local-folder library: scan/classify/index .ns* files into the Library
src/lib/library/	the unified Library model + import store
src/lib/ai/	search ranker — zero-config keyword ranking today, LLM-pluggable behind one interface
src/lib/midi/	live MIDI — note/pedal input that plays the loaded sample (the in-app rompler); not the transfer path (that's vendor USB in device/)
scripts/	USB-protocol tools (nord*.c, libusb) + file-format tooling
docs-site/	the documentation site — Markdown pages in docs-site/src/content/docs/, served at /docs/
docs/	legal stance and contributing notes

Contributing

The reverse-engineering (format + USB transfer protocol) is done and documented. The most valuable contributions now are on the product: the program-visualization UI, the community library, and the AI features. See docs/CONTRIBUTING.md and the maintainers’ notes.

Support

OpenNord is free and open source, built in the open. If it's useful to you and you'd like to help keep the work going, you can buy me a coffee — entirely optional, always appreciated.

Legal

Not affiliated with, endorsed by, or connected to Clavia DMI AB / Nord Keyboards. "Nord" and "Nord Stage" are trademarks of their owner, used here only to describe compatibility. OpenNord shares user-created programs, never Nord's sample/library content. See docs/LEGAL.md.

License

AGPL-3.0-or-later. Free to use, free to study, free to improve — and improvements stay open.