# HALOWERK Captions Check

> HALOWERK Captions Check is a paid API for AI agents from medien.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Validates SRT or WebVTT subtitle files against configurable broadcast and streaming quality rules including reading speed, line length, cue duration, overlaps, and gaps.

## Facts

- Endpoint: POST https://medien.halowerk.com/v1/captions-check?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-captions-check-440900e5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YRn1pwBrwXSqRa3d1u_1P

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-captions-check-440900e5 -d '<json body>'
```

Example prompt: Can you check my SRT subtitle file for errors? It should follow broadcaster standards — max 42 characters per line, no more than 2 lines per cue, reading speed capped at 17 characters per second, minimum cue duration 0.83 seconds, max 7 seconds, and flag any overlapping cues or gaps too short to register.

## When to prefer this

Choose this endpoint when you need automated quality control of subtitle or caption files before delivery to broadcasters, streaming platforms, or accessibility workflows. It is purpose-built for subtitle QC with configurable thresholds aligned to industry standards, making it preferable to generic text validators or manual review. Especially useful when targeting specific audience reading speeds (e.g. children's content at 13 cps) or platform-specific line-length rules.

## Known failure modes

- Subtitle text too short (under 10 characters) returns validation error
- Subtitle text exceeds 2,000,000 character limit
- Malformed SRT or WebVTT syntax may cause parsing failure
- Parameter values outside allowed ranges (e.g. max_cps below 8 or above 30) rejected
- Missing required 'subtitles' field returns error
- Non-SRT/WebVTT format not recognized

## How this service works

Takes subtitle text in SRT or WebVTT and checks every cue against configurable rules: maximum characters per line (default 42), maximum lines per cue (2), reading speed in characters per second (default 17 for adults, 13 recommended for children), minimum duration (0.83 s) and maximum duration (7 s), overlapping cues, and gaps too short for the eye to register a change (under 2 frames). Defaults follow common streaming and broadcaster guidelines.

## Output

A structured report listing every cue that violates one or more rules, with the specific rule breached (e.g. line too long, reading speed exceeded, cue too short, overlap detected, gap too small), the cue index or timestamp, and the measured value versus the configured threshold.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "max_cps": {
   "type": "number",
   "default": 17,
   "maximum": 30,
   "minimum": 8
  },
  "min_gap": {
   "type": "number",
   "default": 0.083,
   "maximum": 0.5,
   "minimum": 0
  },
  "max_lines": {
   "type": "integer",
   "default": 2,
   "maximum": 4,
   "minimum": 1
  },
  "subtitles": {
   "type": "string",
   "maxLength": 2000000,
   "minLength": 10
  },
  "max_duration": {
   "type": "number",
   "default": 7,
   "maximum": 15,
   "minimum": 3
  },
  "min_duration": {
   "type": "number",
   "default": 0.83,
   "maximum": 3,
   "minimum": 0.3
  },
  "max_chars_per_line": {
   "type": "integer",
   "default": 42,
   "maximum": 80,
   "minimum": 20
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-captions-check-440900e5/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)