# audio_tts
A RocketRide pipe node that converts incoming text into spoken audio using the Kokoro-82M text-to-speech engine.
## What it does
Takes text arriving on any of its input lanes, synthesizes it with Kokoro-82M (`hexgrad/Kokoro-82M`), and emits the result on the **audio** lane as WAV bytes (MIME `audio/wav`) via the `writeAudio` BEGIN / WRITE / END sequence. Locally generated audio is mono, 16-bit, 24 kHz; synthesis speed is fixed at 1.
The node runs in one of two modes, chosen automatically at startup:
- **Local**: when no model server is configured, the node installs its own requirements (`numpy`, `kokoro`, `soundfile`) at runtime and constructs a `kokoro.KPipeline` in-process. The spaCy `en_core_web_sm` model (needed by Kokoro's misaki G2P) is downloaded and installed automatically, matched to the installed spaCy version.
- **Model server (`--modelserver`)**: when a model server address is available, the node connects a `ModelClient` and loads the `kokoro` loader on the server instead. The heavy local dependencies are skipped entirely; audio comes back base64-encoded over the inference command.
Audio is written to a temporary WAV file during synthesis and deleted as soon as the bytes have been streamed, including on error, so no orphan files are left on disk. Empty or whitespace-only input is silently skipped and produces no output. Startup fails with `Kokoro: choose a voice from the list` if no voice is configured.
---
## Configuration
### Lanes
All four input lanes produce output on the **audio** lane.
| Input lane | What gets synthesized |
|-------------|-------------------------------------------------------------------------------------------------------------------------|
| `text` | The raw text, as-is. |
| `documents` | The `page_content` of each document, joined with newlines. Documents of type `Image`, `Audio`, or `Video` are skipped. |
| `questions` | The text of every question, joined with spaces. |
| `answers` | The answer text (via `getText()`). |
### Fields
The node has a single profile, **`kokoro`** (the default), selected by the `profile` field.
| Field | Type | Description |
|---|---|---|
| `kokoro_voice` | string | Default "af_heart". Kokoro voice. The language is derived automatically from the voice prefix (af_/am_ → American, bf_/bm_ → British, ef_/em_ → Spanish, etc.). |
| `profile` | string | Default "kokoro". |
### Voices and language
The language is derived automatically from the **first character** of the voice id (`af_*` / `am_*` is American English, `bf_*` / `bm_*` is British English, `ef_*` / `em_*` is Spanish, and so on). Available voice families:
| Prefix | Language | Examples |
|---------------|------------------|---------------------------------------------|
| `af_` / `am_` | American English | `af_heart` (default), `af_bella`, `am_adam` |
| `bf_` / `bm_` | British English | `bf_emma`, `bm_george`, `bm_fable` |
| `jf_` / `jm_` | Japanese | `jf_alpha`, `jm_kumo` |
| `zf_` / `zm_` | Mandarin | `zf_xiaoxiao`, `zm_yunxi` |
| `ef_` / `em_` | Spanish | `ef_dora`, `em_alex` |
| `ff_` | French | `ff_siwis` |
| `hf_` / `hm_` | Hindi | `hf_alpha`, `hm_omega` |
| `if_` / `im_` | Italian | `if_sara`, `im_nicola` |
| `pf_` / `pm_` | Portuguese | `pf_dora`, `pm_alex` |
The full list of voice ids is defined in `services.json`.
---
## Troubleshooting (`Exception: 1` / wasabi)
If misaki/spaCy initialization fails (for example `Exception: 1` or a missing `wasabi` dependency), ensure the spaCy English model is installed: this node downloads `en_core_web_sm` automatically from the official spaCy GitHub release wheel, matched to the installed spaCy version. Verify that `numpy`, `kokoro`, and `soundfile` from `requirements.txt` are installed, and that the model download was not blocked by network restrictions.
---
## Schema
| Field | Type | Description | Default |
|---|---|---|---|
| `audio_tts.kokoro_voice` | `string` | **Voice** Kokoro voice. The language is derived automatically from the voice prefix (af_/am_ → American, bf_/bm_ → British, ef_/em_ → Spanish, etc.). | `"af_heart"` |
| `audio_tts.profile` | `string` | **TTS profile** | `"kokoro"` |
## Dependencies
- `numpy`
- `kokoro` `>=0.9.4`
- `soundfile` `>=0.13.1`
## Source
[ View source](https://github.com/rocketride-org/rocketride-server/tree/develop/nodes/src/nodes/audio_tts)