Third-Party Notices
Melo TTS combines software, data, model weights, and browser assets from multiple projects. The combined application source is distributed under AGPL-3.0-only, but that does not replace the licenses or notices that apply to individual components.
This inventory was reviewed on 2026-10-07. Links identify the upstream source and model cards used for the review. Redistributors should repeat the review before changing a dependency or model revision.
Source provenance
Hangry Labs modifications
Docker packaging, the browser application, API integration, documentation, release tooling, and other fork-specific modifications are copyright 2026 Hangry Labs and contributors and are distributed under AGPL-3.0-only.
Bert-VITS2
The inference architecture and portions of the text-processing implementation are
derived from Bert-VITS2, distributed
under GNU AGPL version 3. This inherited strong-copyleft code is the reason the
combined Melo TTS application is distributed under AGPL-3.0-only. The complete
AGPL text is in LICENSE.
Original MeloTTS
This project is based on MeloTTS by Wenliang Zhao, Xumin Yu, Zengyi Qin, MyShell.ai, and its contributors. MyShell.ai published the original MeloTTS repository with an MIT license and the notice:
Copyright (c) 2024 MyShell.ai
The preserved license is in LICENSES/MIT-MeloTTS.txt.
The combined project is nevertheless distributed under AGPL-3.0-only because it
also contains AGPL-covered Bert-VITS2-derived material.
PaddleSpeech tone sandhi
melo/text/tone_sandhi.py retains the PaddlePaddle copyright and Apache-2.0
header from PaddleSpeech. The
Apache License 2.0 is reproduced in
LICENSES/Apache-2.0.txt.
Tacotron number normalization
melo/text/english_utils/number_norm.py contains code originating in
keithito/tacotron, copyright 2017 Keith
Ito and licensed under MIT. The preserved license is in
LICENSES/MIT-Tacotron.txt.
CMU Pronouncing Dictionary
melo/text/cmudict.rep contains the CMU Pronouncing Dictionary 0.6. Its original
copyright and unrestricted-use notice are retained at the beginning of that file.
Bundled browser components
- WaveSurfer.js: BSD-3-Clause. Its
license is retained in
melo/standalone_ui/static/vendor/wavesurfer/LICENSE. - Lucide: ISC, with MIT-licensed Feather
icons. Its notices are retained in
melo/standalone_ui/static/vendor/lucide/LICENSE.Runtime dependencies
Python packages remain under their own licenses. Their package metadata and
license files are preserved in each installed .dist-info directory in the
Docker image. Notable copyleft or separately licensed runtime components include:
pykakasi: GPL-3.0-or-later.distance: GPL-2.0-or-later, as declared by its distributed package license.num2words: LGPL.- SciPy: BSD-3-Clause. Its license and bundled binary
dependency notices are retained in its installed
.dist-infodirectory. - FFmpeg and its Debian libraries: the Debian build declares GPL-3.0-or-later as
its effective license. Its licenses and source-package notices are retained
under
/usr/share/docin the image. - NVIDIA CUDA runtime libraries installed with the CUDA-enabled PyTorch wheels:
NVIDIA proprietary terms, retained in their
.dist-info/licensesdirectories.
The AGPL license for Melo TTS does not replace these component licenses.
Models and language resources
Melo TTS voice checkpoints
The standard image embeds the following MyShell.ai model repositories, whose model cards declare MIT:
myshell-ai/MeloTTS-Englishmyshell-ai/MeloTTS-English-v2myshell-ai/MeloTTS-English-v3myshell-ai/MeloTTS-Frenchmyshell-ai/MeloTTS-Japanesemyshell-ai/MeloTTS-Chinese
The English-family image embeds only the three English repositories. The MIT
terms reproduced in LICENSES/MIT-MeloTTS.txt apply to these MyShell.ai model
artifacts according to their published model-card metadata.
Spanish myshell-ai/MeloTTS-Spanish and Korean myshell-ai/MeloTTS-Korean
checkpoints are not embedded in published images. An operator may explicitly
download either pinned checkpoint from Hugging Face into their persistent local
volume after reviewing the associated encoder terms below.
Language encoders
google-bert/bert-base-uncased: Apache-2.0.google-bert/bert-base-multilingual-uncased: Apache-2.0.dbmdz/bert-base-french-europeana-cased: MIT.tohoku-nlp/bert-base-japanese-v3: Apache-2.0.dccuchile/bert-base-spanish-wwm-uncased(BETO) is not distributed in the Docker image. Its model card says CC BY 4.0 best describes the authors’ intentions and warns that some training datasets may have incompatible terms, particularly for commercial use. Users should review the BETO model card for their use case and provide attribution to the BETO authors.kykim/bert-kor-baseis not distributed in the Docker image. Its Hugging Face model card does not declare a license. The linked LMkor project is Apache-2.0, but its README instructs commercial model users to arrange a free MOU with the author. Hangry Labs does not grant rights to it; operators must explicitly review its terms before the application downloads it from Hugging Face into their own persistent volume.
Dictionaries and language data
- UniDic is distributed under its upstream GPL/LGPL/BSD choice. The downloaded
dictionary keeps its
COPYING,BSD,GPL,LGPL, andAUTHORSfiles inside the installedunidic/dicdir/licensesdirectory. unidic-literetains the corresponding dictionary notices in its installed package.- NLTK resources and pronunciation data retain their upstream notices in the installed NLTK data/package directories.
Generated audio
The software license does not normally apply to audio generated from user input. Users remain responsible for rights in their input, selected model, voice use, and resulting audio under applicable law and the model-specific terms above.