---
title: FLUX.2 [klein] 9B Base | Runware Docs
url: https://runware.ai/docs/models/bfl-flux-2-klein-9b-base
description: Undistilled foundation model for high-quality image generation and editing
---
# FLUX.2 [klein] 9B Base

FLUX.2 [klein] 9B Base is the undistilled foundation model of the Klein family, offering full model capacity for image generation and editing. It is optimized for fine-tuning, customization, and post-training workflows where flexibility, control, and maximum training signal are required.

- **ID**: `runware:400@3`
- **Status**: live
- **Creator**: Black Forest Labs
- **Release Date**: January 15, 2026
- **Capabilities**: Text to Image, Image to Image, Image Editing

## Pricing

- **1024x1024**: `$0.00416`

## Compatibility & Validation

`width` and `height` must be used together.

## Request Parameters

**API Options**

Platform-level options for task execution and delivery.

### [taskType](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `imageInference`

Identifier for the type of task being performed

### [taskUUID](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.

### [outputType](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-outputtype)

- **Type**: `string`
- **Default**: `URL`

Image output type.

**Allowed values**: `URL` `base64Data` `dataURI`

### [outputFormat](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-outputformat)

- **Type**: `string`
- **Default**: `JPG`

Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.

- \`JPG\`: Best for photorealistic images with smaller file sizes (no transparency).
- \`PNG\`: Lossless compression, supports high quality and transparency (alpha channel).
- \`WEBP\`: Modern format providing superior compression and transparency support.

> [!NOTE]
> \*\*Transparency\*\*: If you are using features like background removal or LayerDiffuse that require transparency, you must select a format that supports an alpha channel (e.g., \`PNG\`, \`WEBP\`, \`TIFF\`). \`JPG\` does not support transparency.

**Allowed values**: `JPG` `PNG` `WEBP`

### [outputQuality](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-outputquality)

- **Type**: `integer`
- **Min**: `20`
- **Max**: `99`
- **Default**: `95`

Compression quality of the output. Higher values preserve quality but increase file size.

### [webhookURL](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-webhookurl)

- **Type**: `string`
- **Format**: `URI`

Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.

**Learn more** (1 resource):

- [Webhooks](https://runware.ai/docs/platform/webhooks) (platform)

### [deliveryMethod](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-deliverymethod)

- **Type**: `string`
- **Default**: `sync`

Determines how the API delivers task results.

**Allowed values**:

- `sync` Returns complete results directly in the API response.
- `async` Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.

**Learn more** (1 resource):

- [Task Polling](https://runware.ai/docs/platform/task-polling) (platform)

### [uploadEndpoint](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-uploadendpoint)

- **Type**: `string`
- **Format**: `URI`

Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.

**Common use cases:**

- **Cloud storage**: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
- **CDN integration**: Upload to content delivery networks for immediate distribution.

```text
// S3 presigned URL for secure upload
https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600

// Google Cloud Storage presigned URL
https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789

// Custom storage endpoint
https://storage.example.com/uploads/generated-image.jpg
```

The content data will be sent as the request body to the specified URL when generation is complete.

### [safety](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-safety)

- **Path**: `safety.checkContent`
- **Type**: `object (2 properties)`

Content safety checking configuration for image generation.

#### [checkContent](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-safety-checkcontent)

- **Path**: `safety.checkContent`
- **Type**: `boolean`
- **Default**: `false`

Enable or disable content safety checking. When enabled, defaults to `fast` mode.

#### [mode](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-safety-mode)

- **Path**: `safety.mode`
- **Type**: `string`
- **Default**: `none`

Safety checking mode for image generation.

**Allowed values**:

- `none` Disables checking.
- `fast` Performs a single check.

### [ttl](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-ttl)

- **Type**: `integer`
- **Min**: `60`

Time-to-live (TTL) in seconds for generated content. Only applies when `outputType` is `URL`.

### [includeCost](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-includecost)

- **Type**: `boolean`
- **Default**: `false`

Include task cost in the response.

### [numberResults](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-numberresults)

- **Type**: `integer`
- **Min**: `1`
- **Max**: `20`
- **Default**: `1`

Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

### [acceleration](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleration)

- **Type**: `string`
- **Default**: `high`

Optimization level.

**Allowed values**: `none` `low` `medium` `high`

### [acceleratorOptions](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions)

- **Path**: `acceleratorOptions.cacheEndStep`
- **Type**: `object (12 properties)`

Advanced caching mechanisms to speed up generation.

#### [cacheEndStep](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-cacheendstep)

- **Path**: `acceleratorOptions.cacheEndStep`
- **Type**: `integer`
- **Min**: `1`

Absolute step number to end caching. Must be greater than `cacheStartStep` and less than or equal to `steps`.

#### [cacheEndStepPercentage](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-cacheendsteppercentage)

- **Path**: `acceleratorOptions.cacheEndStepPercentage`
- **Type**: `integer`
- **Min**: `1`
- **Max**: `100`

Percentage of steps to end caching. Alternative to `cacheEndStep`. Must be greater than `cacheStartStepPercentage`.

#### [cacheMaxConsecutiveSteps](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-cachemaxconsecutivesteps)

- **Path**: `acceleratorOptions.cacheMaxConsecutiveSteps`
- **Type**: `integer`
- **Min**: `1`
- **Max**: `5`
- **Default**: `3`

Limits the maximum number of consecutive steps that can use cached computations before forcing a fresh computation.

#### [cacheStartStep](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-cachestartstep)

- **Path**: `acceleratorOptions.cacheStartStep`
- **Type**: `integer`
- **Min**: `0`

Absolute step number to start caching. Must be less than `cacheEndStep`.

#### [cacheStartStepPercentage](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-cachestartsteppercentage)

- **Path**: `acceleratorOptions.cacheStartStepPercentage`
- **Type**: `integer`
- **Min**: `0`
- **Max**: `99`

Percentage of steps to start caching. Alternative to `cacheStartStep`. Must be less than `cacheEndStepPercentage`.

#### [fbCache](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-fbcache)

- **Path**: `acceleratorOptions.fbCache`
- **Type**: `boolean`
- **Default**: `false`

First Block Cache (FBCache) acceleration. Reuses feature block computations across steps.

#### [fbCacheThreshold](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-fbcachethreshold)

- **Path**: `acceleratorOptions.fbCacheThreshold`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`
- **Step**: `0.01`
- **Default**: `0.25`

Controls the sensitivity threshold for determining when to reuse cached computations. Lower values reuse more aggressively.

#### [teaCache](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-teacache)

- **Path**: `acceleratorOptions.teaCache`
- **Type**: `boolean`
- **Default**: `false`

TeaCache acceleration for transformer-based models. Estimates step differences to skip redundant computations.

#### [teaCacheDistance](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-teacachedistance)

- **Path**: `acceleratorOptions.teaCacheDistance`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`
- **Step**: `0.01`
- **Default**: `0.5`

Controls the aggressiveness of the TeaCache feature. Lower values prioritize quality, higher values prioritize speed.

#### [dbCache](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-dbcache)

- **Path**: `acceleratorOptions.dbCache`
- **Type**: `boolean`
- **Default**: `false`

DB Cache (CacheDiT) acceleration. Caches and reuses intermediate transformer block outputs to skip redundant computations.

#### [dbCacheThreshold](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-dbcachethreshold)

- **Path**: `acceleratorOptions.dbCacheThreshold`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`
- **Step**: `0.01`
- **Default**: `0.25`

Controls the sensitivity threshold for DB Cache. Lower values reuse cached blocks more aggressively, higher values prioritize quality.

#### [dbCacheSkipInterval](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-acceleratoroptions-dbcacheskipinterval)

- **Path**: `acceleratorOptions.dbCacheSkipInterval`
- **Type**: `integer`
- **Min**: `1`
- **Default**: `5`

Controls how many steps to skip between cache refreshes. Higher values skip more steps for faster generation at the cost of quality.

**Inputs**

Input resources for the task (images, audio, etc). These must be nested inside the \`inputs\` object.

### [referenceImages](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-inputs-referenceimages)

- **Path**: `inputs.referenceImages`
- **Type**: `array of strings`

List of reference images (UUID, URL, Data URI, or Base64).

**Generation Parameters**

Core parameters for controlling the generated content.

### [model](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-model)

- **Type**: `string`
- **Required**: true
- **Value**: `runware:400@3`

Identifier of the model to use for generation.

**Learn more** (3 resources):

- [Text To Image: Model Selection The Foundation Of Generation](https://runware.ai/docs/guides/text-to-image#model-selection-the-foundation-of-generation) (guide)
- [Image Inpainting: Model Specialized Inpainting Models](https://runware.ai/docs/guides/image-inpainting#model-specialized-inpainting-models) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [positivePrompt](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-positiveprompt)

- **Type**: `string`
- **Required**: true
- **Min**: `1`
- **Max**: `10000`

Text prompt describing elements to include in the generated output.

**Learn more** (2 resources):

- [Text To Image: Prompts Guiding The Generation](https://runware.ai/docs/guides/text-to-image#prompts-guiding-the-generation) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [negativePrompt](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-negativeprompt)

- **Type**: `string`
- **Min**: `1`
- **Max**: `10000`

Prompt to guide what to exclude from generation. Ignored when guidance is disabled (CFGScale ≤ 1).

**Learn more** (1 resource):

- [Text To Image: Prompts Guiding The Generation](https://runware.ai/docs/guides/text-to-image#prompts-guiding-the-generation) (guide)

### [width](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-width)

- **Type**: `integer`
- **Required**: true
- **Min**: `128`
- **Max**: `2048`
- **Step**: `16`

Width of the generated media in pixels.

**Learn more** (2 resources):

- [Image To Image: Dimensions Changing Aspect Ratio](https://runware.ai/docs/guides/image-to-image#dimensions-changing-aspect-ratio) (guide)
- [Image Outpainting: Dimensions Critical For Outpainting](https://runware.ai/docs/guides/image-outpainting#dimensions-critical-for-outpainting) (guide)

### [height](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-height)

- **Type**: `integer`
- **Required**: true
- **Min**: `128`
- **Max**: `2048`
- **Step**: `16`

Height of the generated media in pixels.

**Learn more** (2 resources):

- [Image To Image: Dimensions Changing Aspect Ratio](https://runware.ai/docs/guides/image-to-image#dimensions-changing-aspect-ratio) (guide)
- [Image Outpainting: Dimensions Critical For Outpainting](https://runware.ai/docs/guides/image-outpainting#dimensions-critical-for-outpainting) (guide)

### [seed](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-seed)

- **Type**: `integer`
- **Min**: `0`
- **Max**: `9223372036854776000`

Random seed for reproducible generation. When not provided, a random seed is generated in the unsigned 32-bit range.

**Learn more** (1 resource):

- [Text To Image: Seed Controlling Randomness Deterministically](https://runware.ai/docs/guides/text-to-image#seed-controlling-randomness-deterministically) (guide)

### [steps](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-steps)

- **Type**: `integer`
- **Min**: `1`
- **Max**: `50`
- **Default**: `28`

Total number of denoising steps. Higher values generally produce more detailed results but take longer.

**Learn more** (1 resource):

- [Text To Image: Steps Trading Quality For Speed](https://runware.ai/docs/guides/text-to-image#steps-trading-quality-for-speed) (guide)

### [scheduler](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-scheduler)

- **Type**: `string`

Scheduler to use for the diffusion process.

**Allowed values**: `DDIM` `DDIMScheduler` `DDPMScheduler` `DEISMultistepScheduler` `Default` `DPM++` `DPM++ 2M` `DPM++ 2M Beta` `DPM++ 2M Exponential` `DPM++ 2M Karras` `DPM++ 2M SDE` `DPM++ 2M SDE Beta` `DPM++ 2M SDE Exponential` `DPM++ 2M SDE Karras` `DPM++ 2M SDE Uniform` `DPM++ 2M Uniform` `DPM++ 3M` `DPM++ 3M Beta` `DPM++ 3M Exponential` `DPM++ 3M Karras` `DPM++ 3M SDE Uniform` `DPM++ 3M Uniform` `DPM++ Beta` `DPM++ Exponential` `DPM++ Karras` `DPM++ SDE` `DPM++ SDE Beta` `DPM++ SDE Exponential` `DPM++ SDE Karras` `DPM++ Uniform` `DPM++ Uniform Beta` `DPM++ Uniform Exponential` `DPM++ Uniform Karras` `DPMSolverMultistepInverse` `DPMSolverMultistepScheduler` `DPMSolverSinglestepScheduler` `EDMDPMSolverMultistepScheduler` `EDMEulerScheduler` `Euler` `Euler a` `Euler Beta` `Euler DiscreteScheduler` `Euler Exponential` `Euler Karras` `EulerAncestralDiscreteScheduler` `FlowMatchEulerDiscreteScheduler` `Heun` `HeunDiscreteScheduler` `Heun Karras` `IPNDMScheduler` `IPNDM Uniform` `IPNDM Uniform Beta` `IPNDM Uniform Exponential` `IPNDM Uniform Karras` `KDPM2AncestralDiscreteScheduler` `KDPM2DiscreteScheduler` `LCM` `LCMScheduler` `LMS` `LMSDiscreteScheduler` `LMS Karras` `PNDMScheduler` `TCDScheduler` `UniPC` `UniPC 2M` `UniPC 2M Karras` `UniPC 2M Uniform` `UniPC 3M` `UniPC 3M Karras` `UniPC 3M Uniform` `UniPC Karras` `UniPC Uniform` `UniPC Uniform Beta` `UniPC Uniform Exponential` `UniPC Uniform Karras`

**Learn more** (2 resources):

- [Text To Image: Scheduler The Algorithmic Path To Your Image](https://runware.ai/docs/guides/text-to-image#scheduler-the-algorithmic-path-to-your-image) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [CFGScale](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-cfgscale)

- **Type**: `float`
- **Min**: `1`
- **Max**: `20`
- **Step**: `0.01`
- **Default**: `3.5`

Guidance scale representing how closely the output will resemble the prompt. Higher values produce results more aligned with the prompt.

**Learn more** (1 resource):

- [Text To Image: Cfg Scale Balancing Creativity And Control](https://runware.ai/docs/guides/text-to-image#cfg-scale-balancing-creativity-and-control) (guide)

### [lora](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-lora)

- **Path**: `lora.model`
- **Type**: `array of objects (3 properties)`

With LoRA (Low-Rank Adaptation), you can adapt a model to specific styles or features by emphasizing particular aspects of the data. This technique enhances the quality and relevance of generated content and can be especially useful when the output needs to adhere to a specific artistic style or follow particular guidelines.

Multiple LoRA models can be used simultaneously to achieve different adaptation goals.

**Examples**:

```json
"lora": [
  {
    "model": "<lora-model-air>",
    "weight": 0.8
  }
]
```

**Learn more** (1 resource):

- [Text To Image: Loras Style And Subject Adapters](https://runware.ai/docs/guides/text-to-image#loras-style-and-subject-adapters) (guide)

#### [model](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-lora-model)

- **Path**: `lora.model`
- **Type**: `string`
- **Required**: true

LoRA model identifier.

#### [weight](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-lora-weight)

- **Path**: `lora.weight`
- **Type**: `float`
- **Min**: `-4`
- **Max**: `4`
- **Step**: `0.01`
- **Default**: `1`

Strength of the LoRA influence. A value of 0 means no influence. Higher values increase the influence, and negative values can be used to steer away from the LoRA's style.

#### [transformer](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-lora-transformer)

- **Path**: `lora.transformer`
- **Type**: `string`
- **Default**: `both`

Transformer stages to apply LoRA. Some video models use separate high-noise and low-noise processing stages, and LoRAs can be selectively applied to optimize their effectiveness.

**Allowed values**:

- `high` Apply LoRA only to the high-noise processing stage (coarse structure and early generation steps).
- `low` Apply LoRA only to the low-noise processing stage (fine details and later generation steps).
- `both` Apply LoRA to both stages for full coverage.

**Features**

Standalone addons and post-processing features.

### [ultralytics](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics)

- **Path**: `advancedFeatures.ultralytics`
- **Type**: `object (8 properties)`

Configuration object for Ultralytics face enhancement during generation. This feature uses face detection and inpainting to improve facial details in the same generation step, without requiring post-processing.

> [!NOTE]
> Face enhancement is available for Stable Diffusion 1.X, SDXL, and FLUX models. The system automatically detects faces and applies targeted refinement to improve quality while maintaining consistency with the overall generation.

#### [CFGScale](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-cfgscale)

- **Path**: `advancedFeatures.ultralytics.CFGScale`
- **Type**: `float`
- **Min**: `0`
- **Max**: `50`
- **Step**: `0.1`
- **Default**: `8`

Face refinement guidance scale.

#### [confidence](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-confidence)

- **Path**: `advancedFeatures.ultralytics.confidence`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`
- **Step**: `0.01`
- **Default**: `0.9`

Confidence threshold for detection.

#### [maskBlur](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-maskblur)

- **Path**: `advancedFeatures.ultralytics.maskBlur`
- **Type**: `integer`
- **Min**: `0`
- **Max**: `100`
- **Default**: `5`

Mask feathering amount. Higher values create softer transitions between the enhanced face region and surrounding areas.

#### [maskPadding](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-maskpadding)

- **Path**: `advancedFeatures.ultralytics.maskPadding`
- **Type**: `integer`
- **Min**: `0`
- **Max**: `20`
- **Default**: `5`

Padding around detected face in pixels. Expands the refinement area to include surrounding context like hair and neck.

#### [negativePrompt](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-negativeprompt)

- **Path**: `advancedFeatures.ultralytics.negativePrompt`
- **Type**: `string`

Negative prompt for detection.

#### [positivePrompt](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-positiveprompt)

- **Path**: `advancedFeatures.ultralytics.positivePrompt`
- **Type**: `string`

Positive prompt for detection.

#### [steps](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-steps)

- **Path**: `advancedFeatures.ultralytics.steps`
- **Type**: `integer`
- **Min**: `1`
- **Max**: `100`
- **Default**: `20`

Number of face refinement steps.

#### [strength](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#request-advancedfeatures-ultralytics-strength)

- **Path**: `advancedFeatures.ultralytics.strength`
- **Type**: `float`
- **Min**: `0`
- **Max**: `1`
- **Step**: `0.01`
- **Default**: `0.3`

Refinement strength. Lower values preserve more of the original, higher values allow more aggressive reconstruction.

## Response Parameters

### [taskType](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `imageInference`

Type of the task.

### [taskUUID](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the task.

### [imageUUID](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-imageuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the output image.

### [imageURL](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-imageurl)

- **Type**: `string`
- **Format**: `URI`

URL of the output image.

### [imageBase64Data](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-imagebase64data)

- **Type**: `string`

Base64-encoded image data.

### [imageDataURI](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-imagedatauri)

- **Type**: `string`
- **Format**: `URI`

Data URI of the output image.

### [seed](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-seed)

- **Type**: `integer`

The seed used for generation. If none was provided, shows the randomly generated seed.

### [NSFWContent](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-nsfwcontent)

- **Type**: `boolean`

Flag indicating if NSFW content was detected.

### [cost](https://runware.ai/docs/models/bfl-flux-2-klein-9b-base#response-cost)

- **Type**: `float`

Task cost in USD. Present when `includeCost` is set to `true` in the request.

## Examples

### Kite Festival Salt Flats (Image to Image)

![Kite Festival Salt Flats](https://assets.runware.ai/examples/bfl-flux-2-klein-9b-base/84b1ec3b-072f-43d3-9c0b-166578ce5daa.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "ecc037b1-34ac-456b-a00e-9f2493600cfe",
  "model": "runware:400@3",
  "positivePrompt": "A vast seasonal salt pan transformed into a surreal kite gathering, mirror-like shallow water reflecting the sky, dozens of gigantic handcrafted kites shaped like moths, seed vessels, and translucent marine forms drifting above small festival tents and scattered visitors, wind ripples across the wet ground, dramatic weather with sunbeams piercing heavy clouds, earthy pigments and chalk white tones, grand scale, crisp atmospheric depth, richly detailed textures, poetic realism, dynamic composition, high-fidelity environmental storytelling",
  "negativePrompt": "text, watermark, logo, frame, low detail, blurry, oversaturated, malformed anatomy, duplicated people, distorted horizon, cropped kites, flat lighting, cartoonish rendering",
  "width": 1344,
  "height": 768,
  "seed": 86189,
  "steps": 32,
  "CFGScale": 3.5,
  "settings": {
    "trueCFGScale": 4
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/7fb2dd53-bfdc-4bd9-b91a-82bdd6753783.jpg",
      "https://assets.runware.ai/assets/inputs/4b80e79e-ddef-4e64-a2b5-8e29029b5207.jpg",
      "https://assets.runware.ai/assets/inputs/eeae0114-3753-4427-befb-ef5bffcb7e74.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "ecc037b1-34ac-456b-a00e-9f2493600cfe",
  "imageUUID": "dfa363b8-f49d-4c40-9d3c-de8e9e6fe2f0",
  "imageURL": "https://im.runware.ai/image/os/a23d05/ws/2/ii/dfa363b8-f49d-4c40-9d3c-de8e9e6fe2f0.jpg",
  "seed": 86189,
  "cost": 0.02743
}
```

---

### Flooded Archive Reading Hall (Image to Image)

![Flooded Archive Reading Hall](https://assets.runware.ai/examples/bfl-flux-2-klein-9b-base/a5d0c0cb-d038-4263-be52-124f1c71e383.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "32a8c2e1-f005-47cd-a47b-7c68c0ce015f",
  "model": "runware:400@3",
  "positivePrompt": "A vast abandoned reading hall partially submerged in clear floodwater, concentric book stacks rising toward a cracked domed ceiling, floating books and loose parchment drifting between long communal tables, tarnished brass lamps, carved walnut shelves, creeping moss and fern growth reclaiming the architecture, pale early sunlight pouring through broken upper windows and reflecting across rippled water, cinematic environmental storytelling, intricate textures, realistic materials, atmospheric depth, elegant composition, high detail",
  "negativePrompt": "people, crowds, vehicles, futuristic technology, glowing signage, low detail, blurry, distorted anatomy, duplicate objects, oversaturated colors, flat lighting, text, watermark, frame",
  "width": 1024,
  "height": 768,
  "seed": 97409,
  "steps": 28,
  "CFGScale": 3.5,
  "settings": {
    "trueCFGScale": 4
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/0d494d30-5fbb-4910-87ae-6ab8901c081d.jpg",
      "https://assets.runware.ai/assets/inputs/7b06a8d8-4dd5-4617-88fe-751265fbcba3.jpg",
      "https://assets.runware.ai/assets/inputs/b3399cae-35c1-4702-b6b4-32871035c7d8.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "32a8c2e1-f005-47cd-a47b-7c68c0ce015f",
  "imageUUID": "02162cc1-2c30-4435-9e3f-9310771fff1c",
  "imageURL": "https://im.runware.ai/image/os/a05d22/ws/2/ii/02162cc1-2c30-4435-9e3f-9310771fff1c.jpg",
  "seed": 97409,
  "cost": 0.01742
}
```

---

### Windup Menagerie Glasshouse Reverie (Text to Image)

![Windup Menagerie Glasshouse Reverie](https://assets.runware.ai/examples/bfl-flux-2-klein-9b-base/571897c3-05f2-436f-87b6-2fff34d7b1d4.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "bc817404-5c74-4ea6-930e-0321c70aa09a",
  "model": "runware:400@3",
  "positivePrompt": "A vast Victorian glasshouse transformed into a mechanical animal sanctuary, filled with brass-and-porcelain windup creatures roaming among enormous ferns and tangled flowering vines. A clockwork giraffe bends its segmented neck toward a suspended feeder of crystal fruit, while tiny silver foxes with key-wound tails dart across mosaic tiles. Sunbeams pour through fogged panes and cast prismatic reflections over damp stone paths, hanging irrigation chains, riveted arches, and scattered maintenance tools. In the distance, a caretaker in a weathered canvas apron stands beside a wheeled cart of springs and polished gears, adding human scale without dominating the scene. Highly detailed materials, believable depth, elegant eccentricity, cinematic framing, atmospheric haze, tactile surfaces, natural color harmony, imaginative worldbuilding, sharp focal detail with gentle falloff.",
  "negativePrompt": "text, watermark, logo, low detail, blurry, oversaturated, malformed anatomy, duplicate animals, floating objects, cropped subject, empty background, harsh digital artifacts",
  "width": 1536,
  "height": 1024,
  "seed": 25079,
  "steps": 32,
  "CFGScale": 3.5,
  "settings": {
    "trueCFGScale": 4
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "bc817404-5c74-4ea6-930e-0321c70aa09a",
  "imageUUID": "4426de19-1a49-4f3e-ba68-6f9b60677d34",
  "imageURL": "https://im.runware.ai/image/os/a17d13/ws/2/ii/4426de19-1a49-4f3e-ba68-6f9b60677d34.jpg",
  "seed": 25079,
  "cost": 0.0091
}
```

---

### Subterranean Seed Vault Cathedral (Text to Image)

![Subterranean Seed Vault Cathedral](https://assets.runware.ai/examples/bfl-flux-2-klein-9b-base/cfba7a54-115c-4e65-a163-740eb0ab368a.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "02af6713-ae9c-4939-889c-58a3af838d8e",
  "model": "runware:400@3",
  "positivePrompt": "A colossal underground seed vault designed like a sacred cathedral, terraced stone aisles descending into a luminous central archive, thousands of labeled glass capsules filled with grains, pods, and rare kernels, root-like bronze conduits branching across vaulted ceilings, suspended pollen-shaped lanterns, robed botanists with field satchels examining ancient drawers, carved murals of extinct crops and seasonal cycles, misty cool air, mineral walls with salt crystals, monumental scale, layered depth, highly detailed textures, quiet reverence, cinematic composition, soft volumetric light, earthy color palette with amber highlights, imaginative speculative archaeology, ultra-detailed environment concept illustration",
  "negativePrompt": "low detail, blurry, oversaturated, text, watermark, logo, duplicate figures, malformed hands, distorted anatomy, cropped composition, flat lighting, cartoonish, generic sci-fi city, modern office, vehicles",
  "width": 1024,
  "height": 1280,
  "seed": 69202,
  "steps": 32,
  "CFGScale": 3.5,
  "settings": {
    "trueCFGScale": 4
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "02af6713-ae9c-4939-889c-58a3af838d8e",
  "imageUUID": "11c6717a-ee4c-414d-b35b-c0a581b487e5",
  "imageURL": "https://im.runware.ai/image/os/a19d05/ws/2/ii/11c6717a-ee4c-414d-b35b-c0a581b487e5.jpg",
  "seed": 69202,
  "cost": 0.00754
}
```