> ## 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.

# FLUX 3 Image Klein

> Black Forest Labs' 5.6B open-weight FLUX 3 image model: text-to-image, editing and multi-reference generation. See parameters, pricing, response fields, and API examples.

Generate and edit images with FLUX 3 Image Klein, the step-distilled 5.6B open-weight FLUX 3 model from Black Forest Labs. One route covers text-to-image, image editing and multi-reference generation with up to 4 reference images.

Try it in the browser: [FLUX 3 Image Klein API playground](https://unifically.com/models/flux-3-image-klein).

## Model

```
black-forest-labs/flux-3-image-klein
```

## Parameters

| Parameter | Type | Required | Default | Description |
| - | - | - | - | - |
| `prompt` | string | Yes | - | Text description of the image, or the edit to apply to the reference images |
| `aspect_ratio` | string | No | `"16:9"` | `"21:9"`, `"16:9"`, `"4:3"`, `"1:1"`, `"3:4"`, `"9:16"`, `"9:21"` |
| `resolution` | string | No | `"1mp"` | `"0.6mp"`, `"1mp"`, `"2mp"`, `"4mp"` |
| `image_urls` | string\[] | No | `null` | Up to 4 reference image URLs for editing or multi-reference generation |
| `steps` | integer | No | `16` | Sampling steps, `1`-`50` |
| `seed` | integer | No | random | Seed for reproducibility |
| `nsfw_check` | boolean | No | `true` | Check uploaded media inputs for NSFW content |

<Note>FLUX 3 Image Klein does not take `guidance`, `negative_prompt` or `prompt_upsampling`. For CFG guidance and a negative prompt use [FLUX 3 Image Klein Base](/models/image/flux/flux-3-image-klein-base).</Note>

## Example Request

```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": "black-forest-labs/flux-3-image-klein",
    "input": {
      "prompt": "A minimalist line drawing of a mountain landscape",
      "aspect_ratio": "16:9",
      "resolution": "1mp",
      "seed": 42
    }
  }'
```

Editing with a reference image:

```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": "black-forest-labs/flux-3-image-klein",
    "input": {
      "prompt": "Keep the composition, change the season to deep winter with snow on every surface",
      "image_urls": ["https://example.com/reference.png"]
    }
  }'
```

## 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>


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