--- license: mit language: en library_name: onnx tags: - text-to-speech - tts - kokoro - piper - kittentts - vits - styletts2 - onnx - sherpa-onnx - on-device - threadcast pipeline_tag: text-to-speech ---

ThreadCast

ThreadCast — Neural Models Mirror

Threads, now a podcast.
threadcast.app · pixellabs.ventures

--- Self-hosted mirror of the on-device neural TTS models used by **[ThreadCast](https://threadcast.app)** across both shipping platforms — the Chrome extension and the Android app. Three engine families on Android (Piper VITS, KittenTTS-nano VITS, Kokoro StyleTTS2), two on the extension, one source of truth. This repository exists so each platform can ship a stable, version-pinned set of model weights without depending on the availability or rate-limits of upstream Hugging Face repos at runtime. > **Note:** if you're a ThreadCast user, you don't need anything here — the extension and the Android app each download (or bundle) what they need automatically. This page is for transparency, contributors, and forks. --- ## Repository layout ``` threadcast-neural-models/ ├── extension/ ← Chrome extension — HF transformers.js packaging │ ├── neural-28m/ Piper VITS — 5 voices, raw HF format │ └── neural-82m/ Kokoro StyleTTS2 — 1 model + 11 voice embeddings │ └── mobile-android/ ← Android app — production zips fetched at runtime └── v1/ 8 zips: 1 shared espeak + 5 per-voice Piper + 1 KittenTTS-nano ("Local AI Plus") + 1 Kokoro ("Local AI Studio") ``` | Subtree | Format | Consumed by | Sub-README | |---|---|---|---| | `extension/` | Raw HF (per-file `.onnx`, `.bin`, `tokenizer.json`) | Chrome extension via `@huggingface/transformers` + `@realtimex/piper-tts-web` | [extension/README.md](extension/README.md) | | `mobile-android/` | ZIP archives, sherpa-onnx packaging | Android app at runtime via [AssetInstaller.kt](https://github.com/Pixel-Labs/Reddit-Reader/blob/main/packages/mobile/modules/threadcast-neural/android/src/main/java/app/threadcast/neural/AssetInstaller.kt) — first-launch download with cancel/delete | [mobile-android/README.md](mobile-android/README.md) | The two subtrees parallel each other on purpose — same engine families (Piper VITS, Kokoro StyleTTS2), same `neural-28m` / `neural-82m` parameter-count naming, just packaged for each platform's runtime. --- ## Engines at a glance | Engine | Architecture | Params | Per-voice cost | Quality tier | |---|---|---|---|---| | **`neural-28m`** | Piper VITS | ~28 M | One ONNX file per voice (~63 MB) | Standard — fast, CPU-friendly, single-thread WASM real-time on a laptop. Surfaced on Android as **Local AI Lite**, on the extension as **AI Neural CPU**. | | **`neural-15m`** | KittenTTS-nano VITS | ~15 M | Single fp16 model + 8 speaker embeddings (one ~26 MB file serves all) | Sweet spot — 8 voices with style-vector switching at a fraction of the storage cost. Android-only, surfaced as **Local AI Plus**. | | **`neural-82m`** | Kokoro StyleTTS2 | ~82 M | Single model + 256-dim style vectors per voice (one ~325 MB file serves all) | Premium — more natural prosody, GPU-accelerated on Chrome (WebGPU); CPU-only on Android (perf-gated). Surfaced on Android as **Local AI Studio**, on the extension as **AI Neural GPU**. | --- ## License This repository **mirrors** upstream models for distribution stability. Each upstream project retains its own license: - **Kokoro-82M:** Apache-2.0 ([upstream model card](https://huggingface.co/hexgrad/Kokoro-82M)) - **KittenTTS-nano (v0.1):** Apache-2.0 ([upstream model card](https://huggingface.co/KittenML/kitten-tts-nano-0.1)) - **Piper voices:** MIT, with individual voice attributions in each `.onnx.json` - **transformers.js, onnxruntime-web, onnxruntime-android:** Apache-2.0 - **sherpa-onnx:** Apache-2.0 The mirror layout, READMEs, and any custom additions in this repository are licensed under MIT by [Pixel Labs](https://pixellabs.ventures). --- ## Links - 🌐 ThreadCast: [threadcast.app](https://threadcast.app) - 🧑‍💻 Pixel Labs: [pixellabs.ventures](https://pixellabs.ventures) - 🐦 Issues / questions: open an issue on the [ThreadCast extension repo](https://threadcast.app/support)