# Tempo Halowerk Video Renderstart Check

> Tempo Halowerk Video Renderstart Check is a paid API for AI agents from tempo.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-16).

Measures and reports the time-to-first-visible-render (renderstart) for a video resource at a given public URL.

## Facts

- Endpoint: POST https://tempo.halowerk.com/v1/pruef/tempo/renderstart/video
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tempo-halowerk-video-renderstart-check-bc01d11a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nq8taQoFqjtSyenq3d8pt

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 tempo-halowerk-video-renderstart-check-bc01d11a -d '<json body>'
```

Example prompt: Can you check how long it takes for the video on https://example.com/page to start visibly rendering — I want to know the renderstart time so I can diagnose slow load complaints.

## When to prefer this

Choose this endpoint when you specifically need to measure the time-to-first-visible-render (renderstart) for a video resource on a public webpage, as opposed to other loading metrics like TTFB, connection time, or byte count. It is the right choice when diagnosing perceived video loading slowness from a user's perspective, since renderstart reflects the moment the video becomes visible rather than lower-level network metrics. Prefer this over general page speed tools when you want an isolated, per-resource video render timing.

## Known failure modes

- URL is not publicly accessible — returns error or timeout
- No video object found at the target URL or matching the CSS selector — returns no-match finding
- Target server blocks automated requests or returns 403/404 — request fails
- Invalid URL format or URL exceeds length limits — validation error
- CSS selector matches no element or matches a non-video element — falls back to first match or returns error

## How this service works

Prüft am Objekt video den Befund Zeit bis zum sichtbaren Renderstart.

## Output

Returns a performance finding (Befund) with the measured time-to-first-visible-render (Renderstart) for the specified video resource, including the numeric duration and associated diagnostic metadata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ziel": {
   "oneOf": [
    {
     "type": "string",
     "maxLength": 2048,
     "minLength": 1,
     "description": "Öffentliche HTTP(S)-Adresse; bei DNS-Befunden Domain oder öffentliche IP."
    },
    {
     "type": "object",
     "required": [
      "adresse"
     ],
     "properties": {
      "adresse": {
       "type": "string",
       "maxLength": 2048,
       "minLength": 1
      },
      "selektor": {
       "type": "string",
       "maxLength": 240,
       "minLength": 1,
       "description": "CSS-Selektor: genau ein Objekt, sonst erster Treffer des Objektfilters."
      },
      "vergleich": {
       "type": "string",
       "maxLength": 2048,
       "description": "Öffentliche Vergleichsadresse für Link-, Sitemap- oder Sprachbefunde."
      },
      "user_agent": {
       "type": "string",
       "pattern": "^[A-Za-z0-9_-]{1,80}$"
      },
      "dkim_selektor": {
       "type": "string",
       "pattern": "^[A-Za-z0-9_-]{1,63}$"
      }
     },
     "additionalProperties": false
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tempo-halowerk-video-renderstart-check-bc01d11a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tempo.halowerk.com](https://www.zero.xyz/host/tempo.halowerk.com/llms.txt)