Fish Audio · Voice

Fish Audio S2 Pro

Non-commercial onlyFish Audio Research License Agreement

Non-commercial, and explicit about it: the upstream download gate makes you tick a box agreeing to non-commercial use only. Soundbox's GGUF download has no gate, but the licence still applies. The licence defines commercial use broadly; internal business operations and indirect revenue count, as well as selling the audio.

fishaudio/s2-pro on Hugging Face audio.cpp

The licence

Summarized from the linked source documents, last checked 25 August 2026. Every claim links to its source; anything unconfirmed is marked unconfirmed.

Fish Audio Research License Agreement

Non-commercial only

Research and non-commercial use only. "Any use of the Fish Audio Materials or Derivative Works for a Commercial Purpose requires a separate written license agreement from Fish Audio." Commercial Purpose is defined broadly: internal business operations and indirect revenue count.

Conditions

Commercial use requires a written agreement with Fish Audio (business@fish.audio).
The original weights are gated: you supply country and date and tick a box agreeing to non-commercial use only, plus a DMCA/legal-compliance consent. Soundbox downloads an ungated GGUF conversion, and the licence still applies to it.
You may not use the materials or their outputs to create or improve any other foundational generative AI model.

What about the audio you generate?

You own the outputs "to the extent permitted by applicable law". Ownership does not lift the non-commercial restriction, and the no-training-on-outputs clause applies to outputs specifically. Few licences in the catalog restrict training on outputs; the DramaBox licence is another.

Correction to the shipped catalog: The shipped catalog says "Unknown" and treats this as conditional. It is a research licence that forbids commercial use without a signed agreement.

Based on the licence text as of the date below. Licences change; the links carry the authoritative version.

Specs

Transcribed from the shipped catalog, audiocpp_models_catalog.json — that file is authoritative if a number here disagrees with it.

Vendor: Fish Audio
Catalog id: audiocpp-fish-audio
audio.cpp loader family: fish_audio
Can do: Text to speech
Weights repo: audio-cpp/audio.cpp-gguf
Weights file: Fish-Audio-S2-Pro-GGUF/fish-audio-s2-pro-q8_0.gguf
Account needed to download: No
Max clip length: 60s
Sample rate: 44.1kHz mono
Approx. VRAM: 3.0 GB
In the picker by default: No — opt in from Settings
Run end-to-end here: No — catalogued, not tested here

Getting it

There is no per-model install. One native binary runs all of these, so getting a model is a download of its weights and nothing else — no virtualenv, no torch pin, no CUDA wheel to match against your driver.

From the CLI

soundbox model install audiocpp
soundbox pull audiocpp-fish-audio

The binary is fetched from audio.cpp's GitHub releases the first time you ask for it and cached under your own data directory. Soundbox ships no native binaries and vendors none.
Weights land in <models dir>/audiocpp/audiocpp-fish-audio/ rather than in the shared Hugging Face cache, so a download stays scoped to the model you asked for.
This one is opt-in: switch it on in the Models page's “Enable more models” section before it appears in the picker.

Worth knowing

Opt-in and untested here. The original weights are gated upstream behind a non-commercial agreement; the GGUF download is ungated, and the licence still applies.

Sources

Primary sources: the model's own repository, the project it came from, and the conversion audio.cpp actually downloads. Never invented — an entry with nothing findable says so instead.

Licence details on these pages are summaries of the linked source documents, last checked 25 August 2026. They are not legal advice, and Soundbox is not affiliated with any model's authors — weights download from Hugging Face under the user's own account and terms. Company and model names identify whose work it is, and belong to their owners. The linked licence text is authoritative; commercial use should be checked against it, per model, before anything ships.