> ## 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.

# Veo 3.1 Lite Video Extension

Video extension API based on the Google Veo 3.1 Lite model, supporting content extension generation for input videos.

<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 generated 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="seed" type="integer">
  Random seed for generating reproducible results

  Value range: \[0, 4294967295]
</ParamField>

<ParamField body="video" type="string" required={true}>
  URL address of the input video, supporting formats such as mp4/mov/mpeg/avi
</ParamField>

<ParamField body="prompt" type="string" required={true}>
  Text prompt describing the content of the extended video (English only)
</ParamField>

<ParamField body="resolution" type="string" default="720p">
  Output video resolution

  Optional values: `720p`, `1080p`
</ParamField>

<ParamField body="aspect_ratio" type="string" default="16:9">
  Output video aspect ratio

  Optional values: `16:9`, `9:16`
</ParamField>

<ParamField body="sample_count" type="integer" default={1}>
  Number of videos to generate

  Value range: \[1, 4]
</ParamField>

<ParamField body="enhance_prompt" type="boolean" default={true}>
  Whether to automatically optimize the prompt
</ParamField>

<ParamField body="generate_audio" type="boolean" default={false}>
  Whether to generate an audio track
</ParamField>

<ParamField body="negative_prompt" type="string">
  Negative prompt, describing content to avoid
</ParamField>

<ParamField body="person_generation" type="string" default="allow_adult">
  Safety control for person generation

  Optional values: `dont_allow`, `allow_adult`
</ParamField>

## Response Information

<ResponseField name="task_id" type="string" required={false}>
  Use the task\_id to request the [Get Task Result API](/en/docs/models/reference-get-async-task-result) to retrieve the generated output.
</ResponseField>