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

# Kling 2.1

> Generate videos with Kling 2.1 models. See supported inputs, parameters, pricing, response fields, and API examples.

Generate high-quality AI videos using Kling 2.1 with flexible generation modes.

## Models

| Model                             | Mode         | Features                                     |
| --------------------------------- | ------------ | -------------------------------------------- |
| `kuaishou/kling-2.1-video`        | `std`, `pro` | Image-to-video only, end frame supported     |
| `kuaishou/kling-2.1-master-video` | `pro` only   | Text-to-video + image-to-video, no end frame |

***

## Kling 2.1

Image-to-video only — `start_frame_url` is required.

### Parameters

| Parameter         | Type    | Required | Default | Description                                                  |
| ----------------- | ------- | -------- | ------- | ------------------------------------------------------------ |
| `prompt`          | string  | **Yes**  | -       | Text prompt describing the video to generate                 |
| `start_frame_url` | string  | **Yes**  | -       | First frame image URL                                        |
| `end_frame_url`   | string  | No       | -       | Last frame image URL                                         |
| `duration`        | integer | No       | `5`     | `5` or `10` seconds                                          |
| `mode`            | string  | No       | `"pro"` | `"std"` (720p) or `"pro"` (1080p)                            |
| `sound_effects`   | object  | No       | -       | Sound effects and music configuration. Omit to disable audio |
| `nsfw_check`      | boolean | No       | `true`  | Check uploaded media inputs for NSFW content                 |

### Example

```bash theme={null}
curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "kuaishou/kling-2.1-video",
    "input": {
      "prompt": "A butterfly landing on a flower in slow motion",
      "start_frame_url": "https://example.com/butterfly.jpg",
      "duration": 5,
      "mode": "pro"
    }
  }'
```

***

## Kling 2.1 Master

Supports both text-to-video and image-to-video. Pro-only mode. No end frame support.

### Parameters

| Parameter         | Type    | Required | Default | Description                                                  |
| ----------------- | ------- | -------- | ------- | ------------------------------------------------------------ |
| `prompt`          | string  | **Yes**  | -       | Text prompt describing the video to generate                 |
| `duration`        | integer | No       | `5`     | `5` or `10` seconds                                          |
| `start_frame_url` | string  | No       | -       | First frame image URL (optional)                             |
| `sound_effects`   | object  | No       | -       | Sound effects and music configuration. Omit to disable audio |
| `nsfw_check`      | boolean | No       | `true`  | Check uploaded media inputs for NSFW content                 |

### Example - Text-to-Video

```bash theme={null}
curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "kuaishou/kling-2.1-master-video",
    "input": {
      "prompt": "Cinematic scene with dramatic lighting",
      "duration": 10,
      "sound_effects": {
        "music": "cinematic orchestral"
      }
    }
  }'
```

### Example - Image-to-Video

```bash theme={null}
curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "kuaishou/kling-2.1-master-video",
    "input": {
      "prompt": "Cinematic scene with dramatic lighting",
      "start_frame_url": "https://example.com/start.jpg",
      "duration": 10
    }
  }'
```

***

## Sound Effects

| Parameter   | Type    | Default | Description                                               |
| ----------- | ------- | ------- | --------------------------------------------------------- |
| `sound`     | string  | `""`    | Sound effect prompt (e.g. "wind blowing, birds chirping") |
| `music`     | string  | `""`    | Background music prompt (e.g. "cinematic orchestral")     |
| `asmr_mode` | boolean | `false` | Enable ASMR-style audio generation                        |

## Response

```json theme={null}
{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "processing"
  }
}
```

<Note>
  **Volume discounts** are available for almost all models. Reach out at [contact@unifically.com](mailto:contact@unifically.com) to discuss custom pricing.
</Note>