# x402engine Voice-Cloning Text-to-Speech (LUX)

> x402engine Voice-Cloning Text-to-Speech (LUX) is a paid API for AI agents from x402engine.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Clones a voice from a reference audio URL and synthesizes new speech from text at 48kHz quality

## Facts

- Endpoint: POST https://x402engine.app/api/tts/lux
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402engine-voice-cloning-text-to-speech-lux-191ab22e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VUFIe3GfcJ3JDCVsQXL0B

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402engine-voice-cloning-text-to-speech-lux-191ab22e -d '<json body>'
```

Example prompt: Clone the voice from this audio clip — https://storage.googleapis.com/falserverless/example_inputs/reference_audio.wav — and say 'Welcome back, it's great to have you here today!' using 4 inference steps and a guidance scale of 3.

## When to prefer this

Choose this endpoint when you need voice-cloning TTS — i.e., you have a reference audio sample and want synthesized speech that matches that specific speaker's voice. Prefer it over standard TTS endpoints when speaker identity matters, for personalized assistants, branded voice experiences, or when replicating a specific person's voice. The 48kHz output and configurable inference steps make it suitable for production-quality audio generation via pay-per-call micropayment with no subscription.

## Known failure modes

- Reference audio URL is unreachable or returns a non-audio file
- Reference audio clip is too long and exceeds max_ref_length limit
- Text input is empty or missing
- Guidance scale or inference steps out of valid range
- Payment of $0.02 USDC not provided or rejected via x402
- Voice cloning fails due to poor-quality or noisy reference audio
- Network timeout during inference

## How this service works

Voice-cloning text-to-speech — provide a reference audio clip and generate speech in that voice at 48kHz

## Output

Returns synthesized 48kHz audio spoken in the cloned voice of the reference speaker, matching the prosody and timbre of the provided audio URL. Output is a high-fidelity audio file or stream reproducing the target voice speaking the requested text.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "bodyType",
    "body",
    "method"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "text",
      "audio_url"
     ],
     "properties": {
      "seed": {
       "type": "number",
       "description": "Random seed for reproducibility"
      },
      "text": {
       "type": "string",
       "example": "Hey, what's up? I'm feeling really great today!",
       "description": "Text to convert to speech"
      },
      "audio_url": {
       "type": "string",
       "example": "https://storage.googleapis.com/falserverless/example_inputs/reference_audio.wav",
       "description": "URL of reference audio file for voice cloning"
      },
      "guidance_scale": {
       "type": "number",
       "default": 3,
       "example": 3,
       "description": "Classifier-free guidance scale (0-10)"
      },
      "max_ref_length": {
       "type": "number",
       "default": 5,
       "example": 5,
       "description": "Max reference audio duration in seconds (1-15)"
      },
      "num_inference_steps": {
       "type": "number",
       "default": 4,
       "example": 4,
       "description": "Flow-matching inference steps (1-16)"
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402engine-voice-cloning-text-to-speech-lux-191ab22e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402engine.app](https://www.zero.xyz/host/x402engine.app/llms.txt)