# HALOWERK Phone Prompt TTS Generator

> HALOWERK Phone Prompt TTS Generator is a paid API for AI agents from medien.halowerk.com, paid per call via x402, $0.07/call, status unknown (last checked 2026-10-31).

Converts up to 30 text prompts into telephone-grade audio files (8 kHz mono WAV, G.711 A-law/µ-law, or MP3) suitable for direct deployment in IVR and phone systems.

## Facts

- Endpoint: POST https://medien.halowerk.com/v1/phone-prompts?utm_source=zero.xyz
- Price: $0.07/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-phone-prompt-tts-generator-912217e8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FHGkecJkFaq6XDhFKjb-l

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 halowerk-phone-prompt-tts-generator-912217e8 -d '<json body>'
```

Example prompt: Generate phone-system audio files for these three IVR prompts in English, G.711 µ-law format: id 'welcome' saying 'Thank you for calling. Please hold.', id 'menu1' saying 'Press 1 for sales, press 2 for support.', id 'goodbye' saying 'Thank you for calling. Goodbye.' — add 0.5 seconds of padding.

## When to prefer this

Choose this endpoint when you need telephone-grade audio (8 kHz, G.711 A-law/µ-law) specifically formatted for IVR or PBX deployment, especially in batch (up to 30 prompts per call). It is ideal for multilingual call centers, automated phone systems, and scenarios where files must be named by ID and dropped directly into a phone platform. Prefer it over generic TTS APIs when the output codec and sample rate must match telephony standards without post-processing conversion.

## Known failure modes

- Prompt text exceeds 1,500 characters per item — returns validation error
- More than 30 prompts submitted — request rejected
- Unsupported language code provided — returns enum validation error
- Invalid prompt ID format (non-alphanumeric/underscore/dash or >40 chars) — rejected
- Total character limit across all prompts exceeded — error returned
- Payment not completed via x402 — 402 Payment Required response
- TTS synthesis failure for a specific language/voice combination — partial or full error

## How this service works

Takes up to 30 prompts, each with an id and its text (total up to 10,000 characters), and returns one audio file per prompt in telephone format: 8 kHz mono WAV in 16-bit PCM, G.711 A-law (Europe) or µ-law (North America), or MP3 for preview. Files are named after the ids so they can be dropped into a phone system. Short silence is added at start and end, as phone systems expect; the voice is selectable per language (English, German, Spanish, French, Italian, Dutch, Japanese).

## Output

One audio file per prompt ID, named by the ID provided, in the requested format (wav_8k 16-bit PCM, alaw, ulaw, or mp3). Audio is 8 kHz mono, telephone-optimized with configurable silence padding at start and end. Up to 30 files can be returned per call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "voice": {
   "type": "string",
   "maxLength": 60
  },
  "format": {
   "enum": [
    "wav_8k",
    "ulaw",
    "alaw",
    "mp3"
   ],
   "type": "string",
   "default": "wav_8k"
  },
  "prompts": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "id",
     "text"
    ],
    "properties": {
     "id": {
      "type": "string",
      "pattern": "^[a-zA-Z0-9_-]{1,40}$"
     },
     "text": {
      "type": "string",
      "maxLength": 1500,
      "minLength": 1
     }
    },
    "additionalProperties": false
   },
   "maxItems": 30,
   "minItems": 1
  },
  "language": {
   "enum": [
    "en",
    "de",
    "es",
    "fr",
    "it",
    "nl",
    "ja"
   ],
   "type": "string"
  },
  "padding_seconds": {
   "type": "number",
   "default": 0.3,
   "maximum": 2,
   "minimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-phone-prompt-tts-generator-912217e8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from medien.halowerk.com](https://www.zero.xyz/host/medien.halowerk.com/llms.txt)