4Z API

Multi-picture reference student video

Endpoint: POST https://4zapi.com/kling/v1/videos/multi-image2video

Parameters

  • Content-Type (header, string): Request body Content-Type, usually application/json
  • Authorization (header, string): Bearer API Key

Request body (application/json)

  • duration (required): Video duration (seconds), required. Only 5 or 10; string/integer OK; gateway normalizes to string. If missing, Relay billing: duration must be 5 or 10.
  • image_list (array<object>, required): Reference images, required, 1–4; each needs image (URL/Base64). Gateway only checks non-empty; format/size by upstream.
  • model_name (string, required): Model name, required. Gateway only allows kling-v1-6; otherwise 400. ["kling-v1-6"]
  • aspect_ratio (string): Aspect ratio, optional. Gateway validates enum when set; otherwise upstream decides. ["16:9", "9:16", "1:1"]
  • callback_url (string): Task completion callback URL; must be publicly reachable; gateway pass-through.
  • cfg_scale (number): CFG, optional. Gateway pass-through; range not pre-validated.
  • external_task_id (string): Caller external task ID for idempotency/reconciliation; not response data.task_id.
  • mode (string): generation mode. billing defaults to std if omitted. 4k not supported. ["std", "pro"]
  • negative_prompt (string): Negative prompt, optional. Gateway pass-through; length not pre-validated (only prompt has 2500 check).
  • prompt (string): Positive prompt, optional. Gateway does not require it; if set, ≤2500 chars. Recommended to guide motion/style.

Request example

{
  "aspect_ratio": "16:9",
  "duration": "5",
  "image_list": [
    {
      "image": "{{image_url_1}}"
    },
    {
      "image": "{{image_url_2}}"
    }
  ],
  "mode": "std",
  "model_name": "kling-v1-6",
  "prompt": "A cinematic scene blending the subjects from reference images, smooth camera movement"
}