---
title: "Kling 4.0 Edit"
description: "Kling 4.0 Edit changes one source video with a text instruction and optional image references and identity elements. It keeps the motion, the cuts and the timing of the source, and it renders at 720p or 1080p. The output is 3 to 30 seconds long."
url: https://docs.roasos.com/models/video-edit/kling-4
---

# Kling 4.0 Edit

<Callout>
  Family 

  `video-edit`

   · model 

  `kling-4`

   · catalog 

  `model-catalog@2026-10-06.v5`

   · pricing 

  `customer-pricing@2026-11-05.v15`

  .
</Callout>

## Endpoint

```http
POST https://api.roasos.com/v1/video-edit/kling-4
```

Send your API key as a bearer token. The key needs the scope `api:write`. Every paid request also needs an `Idempotency-Key` header.

The envelope fields `quote_only`, `quote_id`, `webhook_url` and `wait_timeout_seconds` behave the same on each model endpoint. Refer to [Jobs](/concepts/jobs) and [Quotes and credits](/concepts/quotes-and-credits).

## Good at

Kling 4.0 Edit is the only Kling edit model since 2026-10-29. It replaced the Kling O3 edit endpoints, and those endpoints are removed.

Use it to replace a person or a product in footage that you own, to change the setting, or to change the look. The source video must be 3 to 30 seconds long and at least 700 px on each side. The prompt names the source as `@Video1`. Send `references` (up to 10 images, named `@Image1..N`) for looks and products. Send `elements` (up to 7, each a frontal image and 1 to 3 more views, named `@Element1..N`) to put an exact person or product into the video. Send `avatar_id` to use a saved person as an element, and `product_id` to add the product's kit images as references.

The output length is `duration_seconds` when you send it. Otherwise it is the length of the source, rounded to a whole second.

## Pricing

The unit is one **source\_second**. Pricing key: `kling-4`.

| Request            | Credits |
| ------------------ | ------- |
| `5s_source_720p`   | 12      |
| `5s_source_1080p`  | 17      |
| `10s_source_720p`  | 23      |
| `10s_source_1080p` | 34      |
| `30s_source_720p`  | 68      |
| `30s_source_1080p` | 102     |

The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with `quote_only: true` first.

## Modes

* `edit`

Provider endpoints: `kling/v4/video-to-video/edit`.

## Request fields

| Field                  | Type         | Required | Default | Rule                                                                                                                                                            |
| ---------------------- | ------------ | -------- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `avatar_id`            | string       | no       | —       | UUID                                                                                                                                                            |
| `avatar_outfit`        | string       | no       | —       | ≤ 500 characters                                                                                                                                                |
| `duration_seconds`     | integer enum | no       | —       | `3`, `4`, `5`, `6`, `7`, `8`, `9`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`, `20`, `21`, `22`, `23`, `24`, `25`, `26`, `27`, `28`, `29`, `30` |
| `elements`             | object\[]    | no       | —       | 1–7 items; each `{ frontal_image_url, reference_image_urls }`                                                                                                   |
| `product_id`           | string       | no       | —       | UUID                                                                                                                                                            |
| `prompt`               | string       | yes      | —       | ≥ 1 character; ≤ 2,500 characters                                                                                                                               |
| `quote_id`             | string       | no       | —       | UUID                                                                                                                                                            |
| `quote_only`           | boolean      | no       | `false` | —                                                                                                                                                               |
| `references`           | string\[]    | no       | —       | ≤ 10 items                                                                                                                                                      |
| `resolution`           | enum         | no       | `1080p` | `720p`, `1080p`                                                                                                                                                 |
| `video_url`            | string       | yes      | —       | https URL; ≤ 4,096 characters                                                                                                                                   |
| `wait_timeout_seconds` | integer      | no       | `0`     | 0–60                                                                                                                                                            |
| `webhook_url`          | string       | no       | —       | https URL; ≤ 4,096 characters                                                                                                                                   |

The schema is strict. A field that is not in this table gets `400 unsupported_option`. The field names are the roasOS role names. One role has one name in every family.

## Media

This endpoint accepts these media roles:

* `avatar_id` — identity; the saved character reference sheet, with a derived portrait only where the model requires a single face or source frame
* `elements` — identity; one frontal image plus more views, per person or object
* `product_id` — product; resolves to the product image list
* `references` — style and appearance references
* `video_url` — the source video

| Role         | Items | Maximum size | Content types                           | Duration |
| ------------ | ----- | ------------ | --------------------------------------- | -------- |
| `references` | ≤ 10  | 10 MB        | `image/jpeg`, `image/png`, `image/webp` | —        |
| `video_url`  | ≤ 1   | 100 MB       | `video/mp4`                             | 3–30 s   |

Every other role is refused: `product_images`, `reference_images`, `image_url`, `end_image_url`, `scene_id`, `scene_image`, `video_urls`, `audio_urls`, `audio_url`, `voice_id`. A refused role gets `400 unsupported_option`.

<Callout>
  Each media URL must be an immutable object on 

  `https://cdn.roasos.com`

   that your workspace owns. Any other URL gets 

  `400 reference_media_not_workspace_owned`

  . Refer to 

  [Reference media and uploads](/concepts/reference-media)

   to learn how to put a file there.
</Callout>

## Prompt

Limit 2,500 characters.

* Write only the change: "Replace the person with @Element1. Keep the camera, the cuts and the timing of @Video1."
* Use each `@Image` and `@Element` tag once. The platform adds a missing `@Video1` or `@Image` tag at the end. You must write each `@Element` tag yourself.
* Ask for the existing text in the video to stay, unless you want it removed.
* Do not ask for a new shot plan. The source sets the shots.

## Not exposed

These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.

* `video_url` — these values are not available: `MOV containers`.
* `video_urls` — not accepted by this public endpoint.
* `voice_ids` — not accepted by this public endpoint.

## Result

The result kind is `video`. Always present: `url`.

```json
{
  "data": {
    "id": "gen_…",
    "kind": "video",
    "model": "kling-4",
    "status": "completed",
    "result": {
      "url": "https://cdn.roasos.com/workspaces/ws_01/result"
    }
  }
}
```

The files are immutable objects on `https://cdn.roasos.com`. A result URL is a valid media input for your next request.

## Example

The three steps are always the same: quote, run, poll.

<CodeBlockTabs defaultValue="cURL">
  <CodeBlockTabsList>
    <CodeBlockTabsTrigger value="cURL">
      cURL
    </CodeBlockTabsTrigger>

    <CodeBlockTabsTrigger value="JavaScript">
      JavaScript
    </CodeBlockTabsTrigger>

    <CodeBlockTabsTrigger value="Python">
      Python
    </CodeBlockTabsTrigger>
  </CodeBlockTabsList>

  <CodeBlockTab value="cURL">
    ```bash
    # 1. Quote. Nothing is spent.
    curl -X POST https://api.roasos.com/v1/video-edit/kling-4 \
      -H "Authorization: Bearer roasos_sk_live_..." \
      -H "Idempotency-Key: 0f1c9e2a-kling-4-0001" \
      -H "Content-Type: application/json" \
      -d '{"quote_only":true,"prompt":"A woman holds the bottle at eye level in a bright kitchen, morning light, static camera.","video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
    # 200 { "data": { "kind": "quote", "quote_id": "q_7Hk...", "credits": 12, "expires_at": "...",
    #        "confirmation": { "model": "kling-4", "example": "5s_source_720p" } } }

    # 2. Run. Same body, same Idempotency-Key, quote_id in place of quote_only.
    curl -X POST https://api.roasos.com/v1/video-edit/kling-4 \
      -H "Authorization: Bearer roasos_sk_live_..." \
      -H "Idempotency-Key: 0f1c9e2a-kling-4-0001" \
      -H "Content-Type: application/json" \
      -d '{"quote_id":"q_7Hk...","prompt":"A woman holds the bottle at eye level in a bright kitchen, morning light, static camera.","video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
    # 201 { "data": { "id": "gen_...", "status": "queued", "credits_reserved": 12 } }

    # 3. Poll, then read the result.
    curl https://api.roasos.com/v1/jobs/gen_.../status -H "Authorization: Bearer roasos_sk_live_..."
    curl https://api.roasos.com/v1/jobs/gen_.../result -H "Authorization: Bearer roasos_sk_live_..."
    ```
  </CodeBlockTab>

  <CodeBlockTab value="JavaScript">
    ```javascript
    const key = process.env.ROASOS_API_KEY;
    const url = "https://api.roasos.com/v1/video-edit/kling-4";
    const idempotencyKey = "0f1c9e2a-kling-4-0001";
    const input = {
      "prompt": "A woman holds the bottle at eye level in a bright kitchen, morning light, static camera.",
      "video_url": "https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"
    };

    const post = (payload) =>
      fetch(url, {
        method: "POST",
        headers: {
          Authorization: `Bearer ${key}`,
          "Idempotency-Key": idempotencyKey,
          "Content-Type": "application/json",
        },
        body: JSON.stringify(payload),
      }).then((response) => response.json());

    // 1. Quote. Nothing is spent.
    const quote = await post({ quote_only: true, ...input });
    console.log(quote.data.credits);

    // 2. Run.
    const job = await post({ quote_id: quote.data.quote_id, ...input });

    // 3. Poll, then read the result.
    let status = "queued";
    while (status !== "completed" && status !== "failed" && status !== "canceled") {
      await new Promise((done) => setTimeout(done, 3000));
      const poll = await fetch(`${url.split("/v1")[0]}/v1/jobs/${job.data.id}/status`, {
        headers: { Authorization: `Bearer ${key}` },
      }).then((response) => response.json());
      status = poll.data.status;
    }

    const result = await fetch(`${url.split("/v1")[0]}/v1/jobs/${job.data.id}/result`, {
      headers: { Authorization: `Bearer ${key}` },
    }).then((response) => response.json());
    console.log(result.data.result);
    ```
  </CodeBlockTab>

  <CodeBlockTab value="Python">
    ```python
    import os, time, requests

    key = os.environ["ROASOS_API_KEY"]
    url = "https://api.roasos.com/v1/video-edit/kling-4"
    headers = {
        "Authorization": f"Bearer {key}",
        "Idempotency-Key": "0f1c9e2a-kling-4-0001",
    }
    payload = {
        "prompt": "A woman holds the bottle at eye level in a bright kitchen, morning light, static camera.",
        "video_url": "https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"
    }

    # 1. Quote. Nothing is spent.
    quote = requests.post(url, headers=headers, json={"quote_only": True, **payload}).json()
    print(quote["data"]["credits"])

    # 2. Run.
    job = requests.post(url, headers=headers, json={"quote_id": quote["data"]["quote_id"], **payload}).json()
    job_id = job["data"]["id"]

    # 3. Poll, then read the result.
    jobs = "https://api.roasos.com/v1/jobs"
    status = "queued"
    while status not in ("completed", "failed", "canceled"):
        time.sleep(3)
        status = requests.get(f"{jobs}/{job_id}/status", headers=headers).json()["data"]["status"]

    result = requests.get(f"{jobs}/{job_id}/result", headers=headers).json()
    print(result["data"]["result"])
    ```
  </CodeBlockTab>
</CodeBlockTabs>

## See also

* [`llms.txt` for this model](https://docs.roasos.com/models/video-edit/kling-4/llms.txt) — the same facts as one plain-text file for an agent.
* `GET https://api.roasos.com/v1/catalog/kling-4` — the machine-readable form: enums, defaults, limits and prices. Refer to the [API reference](/api-reference/overview).
* [Jobs](/concepts/jobs) — how to poll a job and read its result.
* Provider endpoints: `kling/v4/video-to-video/edit`.