# Skill: effect/beat-pulse — "פולס על הביט" (Beat pulse)

The frame bumps, flashes or shakes on every beat of the music — the beat is found in the track.
הפריים קופץ, מבזיק או רועד על כל ביט של המוזיקה — הביט מזוהה מתוך הטראק.

Category: Camera & motion · מצלמה ותנועה · a real preview: https://media.gpt.org.il/lookbook/effects/beat-pulse.mp4?v=mv19exzc
Price: **60 credits per finished minute**: the render itself — 1 credit per second of 1080p output. Combined with captions, a hook or other effects: still one render, nothing more for combining.

Base URL: `https://apihub.co.il` · Auth: `Authorization: Bearer <API key>` · Docs: `/docs` (group "Video Effects")
Send `X-Tag: <job name>` on every call of one video; `GET /v1/usage?tag=<job name>` returns what it cost.
**Files are kept 24 hours** — download the finished video.

---

## 1. On its own — one call

```jsonc
POST /v1/effects/beat-pulse             // x-wait-ms: 110000
{
  "video_url": "https://media.gpt.org.il/samples/sample-he.mp4",
  "params": {
    "music_url": "https://media.gpt.org.il/stock/cc0/opengameart/pushing-ahead-push_ahead_0.ogg",
    "amount": 0.8
  }
}
```

A normal render: `status: processing` → poll `GET /v1/executions/{id}` until `completed`, then read `output.url`.

When it plays: the whole video, or a stretch: `start` + `duration`, `at` + `duration`, or `during`.

## 2. With captions, a hook and other effects — the same render

```jsonc
POST /v1/studio/edit               // x-wait-ms: 110000
{
  "video_url": "<the video>",
  "language_code": "he",
  "captions": {
    "style": "classic"
  },
  "effects": [
    {
      "id": "beat-pulse",
      "params": {
        "music_url": "https://media.gpt.org.il/stock/cc0/opengameart/pushing-ahead-push_ahead_0.ogg",
        "amount": 0.8
      }
    }
  ],
  "audio": {
    "normalize": true
  },
  "output": {
    "aspect_ratio": "9:16",
    "resolution": "1080",
    "fit": "crop",
    "quality": "high"
  }
}
```

`effects` is a list: add more entries for more effects. The engine applies them by pipeline stage (cuts and time →
camera → grade and looks → overlays → text and captions → sound), never by their order in the list. An edit has one
`transition`, one `color` grade, one `music` bed, one `speed` and one caption style: two effects that set the same
one are refused with a message that names them.

## 3. Params

| param | default | range / options | what it does |
|---|---|---|---|
| `on` | `"zoom"` | `zoom` · `flash` · `shake` | What happens on a beat |
| `amount` | `0.5` | 0.1–1 | How strong |
| `every` | `1` | value | Every beat, every 2nd, every 4th |
| `bpm` | `null` | value | The tempo (null = found in the music) |
| `offset_ms` | `null` | value | With `bpm`: where the first beat is, ms |
| `music_url` | `null` | value | A music bed to add and pulse to (null = the edit's own music, or the video's sound) |
| `music_volume` | `0.35` | 0–1 | The bed's level, with music_url |

GET `/v1/effects/beat-pulse` returns the same as JSON (with the full body schema). Every field has a default; numbers
outside their range are refused with the field's name.