| # ChatBack AI Model Mirror | |
| Stable mirrors of on-device AI models used by the [ChatBack](https://github.com/Chazzo2008/chatback) Android app. | |
| All inference runs **100% locally on the user's device** — no data is sent to any server. | |
| See [NOTICE.md](NOTICE.md) for full attribution and licensing. | |
| --- | |
| ## Models | |
| ### Base Model (Required) | |
| | Model | File | Size | License | | |
| |-------|------|------|---------| | |
| | **Gemma 3 1B-IT** (q4_block128, ekv4096, LiteRT) | `gemma3-1b/Gemma3-1B-IT_multi-prefill-seq_q4_block128_ekv4096.task` | ~556 MB | Gemma Terms of Use | | |
| Powers all chatroom AI features: smart replies, tone warnings, draft assistant, | |
| auto-translation, summarisation, and AI Chat (when no large model is activated). | |
| True 4 096-token KV cache baked into the .task file. Fast, low-RAM (~2 GB+), GPU/NPU-accelerated via LiteRT. | |
| ### AI Chat Upgrade (Optional — requires base model) | |
| | Model | File | Size | License | | |
| |-------|------|------|---------| | |
| | **Gemma 4 E2B-IT** (LiteRT) | `gemma4-e2b/gemma-4-E2B-it.litertlm` | ~2.5 GB | Gemma Terms of Use | | |
| | **Gemma 4 E2B-IT Abliterated** (NSFW, LiteRT) | `gemma4-e2b/Gemma-4-E2B-it-abliterated.litertlm` | ~2.5 GB | Gemma Terms of Use | | |
| Best AI Chat quality. Loaded only while AI Chat is open; base model restores | |
| automatically when you leave AI Chat. Requires 3 GB+ RAM. | |
| The abliterated variant has safety alignment removed and is only visible when | |
| NSFW mode is enabled in the app. | |
| ### Text-to-Speech | |
| | Model | Size | License | | |
| |-------|------|---------| | |
| | **Piper TTS** — Amy, Lessac, LibriTTS-R, Ryan, Joe (ONNX medium) | ~178 MB total | MIT | | |
| | **Kokoro TTS** English v1.0 (q8f16 ONNX, 28 voices) | ~100 MB | Apache 2.0 | | |
| Kokoro uses mixed int8-weight/float16-activation quantization for better audio quality | |
| vs pure int8. The app uses its own Java IPA phonemizer — no espeak-ng dependency. | |
| --- | |
| ## Download URLs used by the app | |
| ``` | |
| # Base model | |
| https://huggingface.co/Chazzo2008/chatback-ai-models/resolve/main/gemma3-1b/Gemma3-1B-IT_multi-prefill-seq_q4_block128_ekv4096.task | |
| # Large model upgrade | |
| https://huggingface.co/Chazzo2008/chatback-ai-models/resolve/main/gemma4-e2b/gemma-4-E2B-it.litertlm | |
| # Large model — NSFW abliterated variant | |
| https://huggingface.co/Chazzo2008/chatback-ai-models/resolve/main/gemma4-e2b/Gemma-4-E2B-it-abliterated.litertlm | |
| ``` | |