Third-Party Notices
Effective date: February 8, 2026
Last updated: September 8, 2026
Operational Service Providers
The Service also relies on external providers that are not open-source library
dependencies:
| Provider | Role |
|---|---|
| Hetzner Cloud | Hosts the beta application, database, processing workers, and uploaded artifacts on a VM and attached volume in Helsinki, Finland (EU). |
| Brevo | Provides transactional SMTP delivery for account verification, password-reset, and support-related email. |
| Sentry | Provides application error monitoring and diagnostics. |
| ImprovMX | Forwards inbound aliases used for support and security contact handling. |
| Vercel | Provides DNS management for the public domain. |
The Privacy Policy and applicable data-processing review determine which
personal data each provider may process and the relevant retention and transfer
requirements.
Backend Dependencies (Python)
| Package | Version | License |
|---|---|---|
| asyncpg | 0.31.0 | Apache-2.0 |
| alembic | 1.13.2 | MIT |
| basic-pitch[onnx] | 0.3.2 | Apache-2.0 |
| demucs | 4.0.1 | MIT |
| email-validator | 2.2.0 | Unlicense |
| fastapi | 0.129.0 | MIT |
| filetype | 1.2.0 | MIT |
| librosa | 0.11.0 | ISC |
| matplotlib | 3.10.8 | PSF (Python Software Foundation License) |
| music21 | 9.9.1 | BSD-3-Clause |
| mutagen | 1.47.0 | GPL-2.0-or-later |
| numpy | 1.26.4 | BSD-3-Clause |
| pandas | 3.0.1 | BSD-3-Clause |
| pretty_midi | 0.2.11 | MIT |
| psycopg2-binary | 2.9.9 | LGPL (with static-linking exception) |
| pydantic | 2.12.5 | MIT |
| PyJWT | 2.13.0 | MIT |
| argon2-cffi | 25.1.0 | MIT |
| passlib[argon2] | 1.7.4 | BSD |
| jsonschema | 4.22.0 | MIT |
| python-dotenv | 1.2.2 | BSD-3-Clause |
| python-multipart | 0.0.31 | Apache-2.0 |
| python-magic | 0.4.27 | MIT |
| pyclamd | 0.4.0 | LGPL-3.0-or-later |
| redis | 7.2.0 | MIT |
| rq | 2.6.1 | BSD-2-Clause |
| soundfile | 0.13.1 | BSD-3-Clause |
| SQLAlchemy | 2.0.48 | MIT |
| torch | 2.1.2 | BSD-3-Clause |
| torchaudio | 2.1.2 | BSD License |
| uvicorn | 0.41.0 | BSD-3-Clause |
| sentry-sdk | 1.45.1 | MIT |
Copyleft dependencies
mutagen (GPL-2.0-or-later) is used as a library
for audio metadata reading, not modified or statically linked into a
distributed binary — the app is server-side Python run as a service, not
distributed to end users as a combined work. psycopg2-binary (LGPL, with
the psycopg exception permitting static linking) and pyclamd
(LGPL-3.0-or-later) are weak-copyleft, standard for library use.
Frontend Dependencies (Node)
| Package | Version | License |
|---|---|---|
| @coderline/alphatab | 1.8.3 | MPL-2.0 |
| @tailwindcss/postcss | 4.2.1 | MIT |
| clsx | 2.1.1 | MIT |
| lucide-react | 0.547.0 | ISC |
| next | 16.3.1 | MIT |
| next-themes | 0.4.6 | MIT |
| postcss | 8.5.23 | MIT |
| react | 19.2.1 | MIT |
| react-dom | 19.2.1 | MIT |
| tailwind-merge | 3.5.0 | MIT |
| tailwindcss | 4.2.1 | MIT |
| wavesurfer.js | 7.12.1 | BSD-3-Clause |
Copyleft dependency
@coderline/alphatab (MPL-2.0, weak file-level
copyleft) is used as-is via npm, unmodified. MPL's disclosure obligation
triggers on distributing modified MPL-covered source files, which this
project does not do.
Frontend Bundled Assets
Not npm packages — binary soundfont assets served from public/alphatab/soundfont/
and loaded by @coderline/alphatab's player at runtime, unmodified from their
official upstream distributions.
| Asset | Source | License |
|---|---|---|
musescore-general.sf3 | MuseScore_General v0.2, MuseScore project | MIT (see below) |
sonivox.sf3 | Sonivox EAS GM soundfont, bundled with @coderline/alphatab | Apache-2.0 (soundfont/LICENSE) |
musescore-general.sf3's license (soundfont/LICENSE-musescore-general.md,
fetched from the official distribution) requires the full attribution chain
to be reproduced in any derivative work:
- FluidR3 (original) — Copyright (c) 2000-02 Frank Wen
- FluidR3Mono (mono conversion) — Copyright (c) 2014-17 Michael Cowgill
- MuseScore_General adaptation — Copyright (c) 2018-19 S. Christian Collins
- Temple Blocks instrument — Copyright (c) 2002 Ethan Winer
- Drumline Cymbals — Copyright (c) 2016 Michael Schorsch
All shared under the MIT license.