vox-indextts

vox-indextts provides a Vox TTS adapter for IndexTTS2.

Adapters:

• indextts-tts-torch - IndexTTS2 voice cloning backend

Install

pip install vox-indextts

Runtime Dependencies

The adapter package is intentionally light. The upstream IndexTTS runtime is installed on demand from GitHub into the isolated target runtime $VOX_HOME/runtime/indextts.

During vox pull, the adapter verifies or installs the IndexTTS runtime without loading model weights. The upstream package source is installed without its transitive dependencies so it does not pull a second Torch/CUDA stack into the adapter runtime. Curated non-Torch runtime dependencies live under $VOX_HOME/runtime/indextts; model weights remain in the normal Vox model store.

Use with Vox

vox pull indextts-tts:2
vox run indextts-tts:2 "Hello from IndexTTS" --voice /path/to/reference.wav

IndexTTS is a voice-cloning backend. Pass reference_audio through the Vox API or use a voice value that points to a local WAV file.

IndexTTS2 emotion controls are exposed through Vox synthesis params:

• emo_alpha (number, default backend value, range 0..1) controls emotion conditioning strength.
• use_emo_text (boolean, default false) asks IndexTTS2 to infer emotion from the synthesis text.
• emo_text (string, optional) supplies separate emotion-description text and implies use_emo_text=true.
• emo_audio_prompt (string, optional) supplies a server-side audio file path used as the IndexTTS2 emotional reference prompt.
• use_random (boolean, default false) enables stochastic emotion sampling; upstream notes that this may reduce voice-cloning fidelity.
• emotion_happy, emotion_angry, emotion_sad, emotion_afraid, emotion_disgusted, emotion_melancholic, emotion_surprised, and emotion_calm (numbers, default 0, range 0..1) map to the IndexTTS2 eight-float emo_vector order. The adapter rejects vectors whose values sum above 1.5.

Upstream IndexTTS2 describes duration control, but the current release notes say that functionality is not enabled. Vox therefore does not expose a duration parameter for this adapter yet.

The current Vox adapter is classified for Linux x86_64 CUDA/Torch runtimes. CPU, ONNX, and Spark/ARM NVIDIA paths are not currently production-supported by this adapter. Upstream documents CPU-style constructor switches, but Vox has not validated those paths with acceptable latency or portable dependency resolution. Plan for at least 10GiB of usable VRAM budget before deployment headroom.