Image to Video

Kling 4.0 starts the video from your image, and can also pass through keyframes and end on a last frame, generating what happens in between.

Create a task

Use the shared create endpoint with model: "kling-4.0". It usually responds in under 1 second and the cost is frozen within a few seconds; the video usually takes 1–5 minutes. Get the result once the task has finished.

Headers

Body

video_url and video_urls aren't accepted: sending either returns 400 invalid_request with param set to it.

A first frame, a keyframe and a last frame, 720p, 5 seconds:

curl https://api.nanoapi.ai/v1/tasks \
  -H "Authorization: Bearer $NANOAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "kling-4.0",
    "mode": "image_to_video",
    "image_urls": [
      "https://example.com/start.jpg",
      "https://example.com/middle.jpg",
      "https://example.com/end.jpg"
    ],
    "prompt": "A slow camera flight from the mountains down to the lake",
    "aspect_ratio": "auto",
    "resolution": "720p",
    "duration": 5
  }'

Response: 200 OK. data is the newly created task, with only these fields; each one is described in Create a task: Response. Keep data.id to get the result: once the task succeeds, the video is at data.outputs[0].url of the retrieved task or the webhook. The task can still fail after it's created (for example a file can't be downloaded), so go by what retrieving the task or the webhook tells you.

{
  "code": 200,
  "message": "success",
  "data": {
    "object": "task",
    "id": "tk_01jbc4k7m2n9p5q8r3s6t1v4w7",
    "model": "kling-4.0",
    "status": "queued",
    "error": null,
    "created_at": "2026-10-30T08:30:00Z"
  }
}

Pricing

cost = duration × price per second of the resolution

Loading the current prices…

Example: 720p for 5 seconds (the request above) costs 5 × the 720p price per second.

Billed seconds are the duration you ask for, however many images you send. Prices change, so read the current ones from GET /v1/products (the prices rows whose mode is this mode) instead of hard-coding them; billing.frozen on the retrieved task is what counts. All Kling 4.0 prices: Kling 4.0 → Pricing.

Errors

Create request errors: the request fails with an HTTP error and no task is created. Specific to this mode:

Other errors of the create endpoint (401, 402, 429 and so on): Create a task → Errors.

Task failures: the create request succeeded (200) and the task later turned failed. There's no HTTP status: the reason is the task's error.type, from retrieving the task or the webhook.

Failure reasons shared by every mode (such as a balance too low for the task): Kling 4.0 → Errors; all of them: Failure reasons.