kling v4.0 · video extend

Options and pricing

Task: video-extend. Catalog base price: $0.157. The exact quote depends on your inputs; the catalog price is not a fixed per-task charge.

We reserve the quoted maximum before submission, settle the actual generation cost and release the remainder. Set jev.max_cost_usd to your maximum reservation. A quote above this limit is rejected before generation.

{
  "type": "object",
  "required": [
    "prompt",
    "video"
  ],
  "properties": {
    "video": {
      "type": "string",
      "description": "URL of the video to extend. The new segment is generated from its last frame and appended to the original."
    },
    "prompt": {
      "type": "string",
      "description": "Describe the continuation - action, camera movement, lighting and sound. Audio is generated together with the picture."
    },
    "duration": {
      "enum": [
        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
      ],
      "type": "integer",
      "default": 5,
      "description": "Length in seconds of the new segment to append (3-30).",
      "x-ui-component": "select"
    },
    "last_image": {
      "type": "string",
      "description": "Optional target last-frame image URL. When provided, the new segment interpolates from the input video's last frame to this image."
    },
    "resolution": {
      "enum": [
        "720p",
        "1080p"
      ],
      "type": "string",
      "default": "720p",
      "description": "Resolution of the new segment.",
      "x-ui-component": "select"
    }
  },
  "x-order-properties": [
    "prompt",
    "video",
    "last_image",
    "resolution",
    "duration"
  ],
  "additionalProperties": false
}

Required fields and conditional rules come from the published schema. Catalog support does not mean every option has been independently tested by Jevrouter. Synchronous generation, base64 output and customer callbacks are unavailable.

Allow this model on your Jevrouter key. Replace every placeholder below with a value of the correct type, set a USD limit, and supply any conditional fields required by the schema. Media inputs must use your own accessible URLs; this endpoint does not upload files.

curl https://api.jevrouter.io/v1/videos \
  -H "Authorization: Bearer $JEVROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: video-demo-001" \
  -d @- <<'JSON'
{
  "model": "kwaivgi/kling-v4.0/video-extend:video",
  "input": {
    "video": "<video: provide string>",
    "prompt": "<prompt: provide string>",
    "duration": 5,
    "resolution": "720p"
  },
  "jev": {
    "max_cost_usd": "YOUR_USD_LIMIT"
  }
}
JSON

Save data.id and data.urls.get. An accepted task continues even if you disconnect.

Let Jevrouter choose

Use jev/auto as the model and set task to video-extend. Your project must enable Auto, and both the project and key must allow Auto and the candidate models.

Auto checks the task type and all supplied input fields against each candidate. It compares live quotes for up to eight compatible candidates, shortlisted by catalog base price. It selects the lowest quote within that shortlist and your budget; this is not a quality ranking or a guarantee of the cheapest model in the entire catalog.

Use common options such as duration, resolution and aspect_ratio at the top level where available. Model-specific options belong in input and may narrow the pool. Unsupported options are rejected, never silently dropped. Without task, Auto defaults to text-to-video.

curl https://api.jevrouter.io/v1/videos/REQUEST_ID \
  -H "Authorization: Bearer $JEVROUTER_API_KEY"

Replace REQUEST_ID with your task ID. Wait at least three seconds between checks. Status progresses from queued to processing, then completed or failed. Results appear in data.outputs as media URLs or structured output objects.

If the submission response is lost, repeat the original request with the same idempotency key. A new key may create another billed task.

Results and billing

View the request in your dashboard or query /v1/requests/REQUEST_ID for reservation and settlement details. Results may be ready before the bill arrives.

Result links are retained for up to seven days and may expire earlier. Save your video while it is available. Anyone with a media URL may be able to access it. Cancellation and customer webhooks are not available.

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