# HALOWERK audiowerk Speech Duration Estimator

> HALOWERK audiowerk Speech Duration Estimator is a paid API for AI agents from audio.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Estimates the duration of spoken audio for a given text, delivery style, language, and pause settings without generating the audio itself.

## Facts

- Endpoint: POST https://audio.halowerk.com/speech-duration
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-audiowerk-speech-duration-estimator-e6fc55fa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mxVf_UpNKZU56B3MoNdnO

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-audiowerk-speech-duration-estimator-e6fc55fa -d '<json body>'
```

Example prompt: How long would this video script take to narrate in English at a conversational pace, with 300ms comma pauses and 800ms sentence pauses? Here's the text: 'Welcome to our product tour. Today, we'll walk through the main features.'

## When to prefer this

Use this endpoint when you need to estimate audio duration before committing to full TTS generation, to validate script length fits a time slot, or to plan audio production budgets. It is far cheaper and faster than generating audio and discarding it. Prefer this over silence-removal or normalization endpoints when the goal is pre-production timing rather than post-production audio editing.

## Known failure modes

- Text exceeds 40,000 character limit — request rejected with validation error
- Invalid or unsupported language code provided — defaults may not apply correctly
- syllables_per_second provided without delivery=custom — parameter may be ignored
- Payment of 0.002 USDC not completed via x402 — 402 Payment Required response
- Text too short (empty string) — minimum length validation failure
- Invalid delivery enum value — schema validation error

## How this service works

HALOWERK audiowerk — bezahlte Endpunkte nach x402. Preise in USDC auf Base Mainnet.

## Output

Returns a computed duration estimate (likely in seconds or milliseconds) representing how long the provided text would take to be spoken, accounting for the chosen delivery rate (syllables per second), language-specific syllable rules, and the configured pause durations at commas, sentences, and paragraph breaks.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "maxLength": 40000,
   "minLength": 1,
   "description": "The text to be spoken."
  },
  "delivery": {
   "enum": [
    "slow",
    "narration",
    "conversational",
    "brisk",
    "custom"
   ],
   "type": "string",
   "default": "narration",
   "description": "Delivery style. Each carries its own syllables per second."
  },
  "language": {
   "enum": [
    "de",
    "en",
    "fr",
    "es",
    "it",
    "nl",
    "pt"
   ],
   "type": "string",
   "default": "en",
   "description": "Language of the text. Decides which syllable rules apply."
  },
  "comma_pause_ms": {
   "type": "integer",
   "default": 200,
   "maximum": 1500,
   "minimum": 0,
   "description": "Pause added at a comma, semicolon, colon or dash."
  },
  "sentence_pause_ms": {
   "type": "integer",
   "default": 600,
   "maximum": 3000,
   "minimum": 0,
   "description": "Pause added at a full stop, question mark or exclamation mark."
  },
  "paragraph_pause_ms": {
   "type": "integer",
   "default": 900,
   "maximum": 5000,
   "minimum": 0,
   "description": "Pause added at a blank line."
  },
  "syllables_per_second": {
   "type": "number",
   "maximum": 12,
   "minimum": 1,
   "description": "Own rate, only with delivery=custom."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-audiowerk-speech-duration-estimator-e6fc55fa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from audio.halowerk.com](https://www.zero.xyz/host/audio.halowerk.com/llms.txt)