> ## Documentation Index
> Fetch the complete documentation index at: https://docs.jiekou.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Kling V2.1 Image-to-Video

Kling V2.1 is Kuaishou’s latest-generation AI-powered image-to-video model. It can generate high-quality, cinematic short videos from a single image or text prompt with one click. Compared with Kling 2.0, version 2.1 delivers major breakthroughs in motion smoothness, visual consistency, and prompt understanding.

<Tip>
  This is an **asynchronous** API and only returns the asynchronous task’s task\_id. You should use this task\_id to request the [Get Task Result API](/en/docs/models/reference-get-async-task-result) to retrieve the video generation result.
</Tip>

## Request Headers

<ParamField header="Content-Type" type="string" required={true}>
  Enum value: `application/json`
</ParamField>

<ParamField header="Authorization" type="string" required={true}>
  Bearer authentication format: Bearer \{\{API key}}.
</ParamField>

## Request Body

<ParamField body="image" type="string" required={true}>
  The first-frame image of the video. Supported image formats include `.jpg`, `.jpeg`, and `.png`. The image file size must not exceed 10MB, and the resolution must be at least 300×300 pixels.
</ParamField>

<ParamField body="prompt" type="string" required={true}>
  The positive text prompt for generating the video, up to 2500 characters.
</ParamField>

<ParamField body="mode" type="string" required={false}>
  Video generation mode.

  Supported:

  * `Standard`: Fast generation, low cost, generates 720p videos.
  * `Professional`: High quality, high cost, generates 1080p videos.

  Default value: `Standard`.
</ParamField>

<ParamField body="duration" type="string" default="5">
  The duration of the generated video (in seconds).

  Available values: `5`, `10`
</ParamField>

<ParamField body="guidance_scale" type="number" default={0.5}>
  Guidance strength parameter, controlling how closely the generated content follows the prompt.

  Value range: 0 to 1<br />
  Step: 0.01
</ParamField>

<ParamField body="negative_prompt" type="string">
  Negative prompt, used to avoid undesired content; no more than 2500 characters.
</ParamField>

## Response Information

<ResponseField name="task_id" type="string" required={true}>
  The task\_id of the asynchronous task. You should use this task\_id to request the [Get Task Result API](/en/docs/models/reference-get-async-task-result) to obtain the generation result.
</ResponseField>