MODEL ID bfl:5@1

live

FLUX.2 [pro]

by Black Forest Labs November 26, 2025

FLUX.2 [pro] is a flow-matching latent transformer for precise text-to-image synthesis and reference-guided editing. It supports multi image references, 4MP outputs, and Mistral-based text conditioning for controllable composition and robust iterative edits that preserve structure.

API Options

Platform-level options for task execution and delivery.

taskType string required value: imageInference: Identifier for the type of task being performed

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

outputType string default: URL: Image output type.

Allowed values 3 values

outputFormat 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.

**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 3 values

outputQuality integer min: 20 max: 99 default: 95: Compression quality of the output. Higher values preserve quality but increase file size.

webhookURL string 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
PLATFORM

deliveryMethod string default: sync

Determines how the API delivers task results.

Allowed values 2 values

: Returns complete results directly in the API response.
: Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.

Learn more 1 resource

Task Polling
PLATFORM

uploadEndpoint string 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.

// 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 object

Content safety checking configuration for image generation.

Properties 2 properties

safety » checkContent checkContent boolean default: false: Enable or disable content safety checking. When enabled, defaults to fast mode.

safety » mode mode string default: none

Safety checking mode for image generation.

Allowed values 2 values

: Disables checking.
: Performs a single check.

ttl integer min: 60: Time-to-live (TTL) in seconds for generated content. Only applies when outputType is URL.

includeCost boolean default: false: Include task cost in the response.

numberResults integer min: 1 max: 20 default: 1: Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

Inputs

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

inputs » referenceImages referenceImages array of strings min items: 1max items: 9: List of reference images (UUID, URL, Data URI, or Base64).

Generation Parameters

Core parameters for controlling the generated content.

model string required value: bfl:5@1

Identifier of the model to use for generation.

Learn more 3 resources

positivePrompt string required min: 1 max: 32000

Text prompt describing elements to include in the generated output.

Learn more 2 resources

width integer required min: 256 max: 2048 step: 16

Width of the generated media in pixels.

Learn more 2 resources

height integer required min: 256 max: 2048 step: 16

Height of the generated media in pixels.

Learn more 2 resources

seed 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
GUIDE

Provider Settings

Parameters specific to this model provider. These must be nested inside the providerSettings.bfl object.

providerSettings » bfl » promptUpsampling promptUpsampling boolean default: false: Enable automatic enhancement and expansion of the input prompt.

providerSettings » bfl » safetyTolerance safetyTolerance integer min: 0 max: 6 default: 2: Tolerance level for content moderation. Lower values are stricter; higher values are more permissive.

taskType string required value: imageInference: Type of the task.

taskUUID string required UUID v4: UUID of the task.

imageUUID string required UUID v4: UUID of the output image.

imageURL string URI: URL of the output image.

imageBase64Data string: Base64-encoded image data.

imageDataURI string URI: Data URI of the output image.

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

NSFWContent boolean: Flag indicating if NSFW content was detected.

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

Image to Image

Volcanic Glasshouse Orchid Procession

Request

{
  "taskType": "imageInference",
  "taskUUID": "95a328fa-7359-4afd-91f9-6fc8d09071b5",
  "model": "bfl:5@1",
  "positivePrompt": "Create a grand scene inside a volcanic glasshouse where a ceremonial orchid procession crosses black basalt paths between terraced pools and towering panes of curved glass. Use the reference images to blend architecture, rare flowers, and the procession into one cohesive composition. Emphasize glossy obsidian stone, mineral haze, copper framework, dense humid air, intricate botanical textures, and rhythmic spacing of figures under woven canopies. Cinematic scale, precise perspective, natural color harmony, refined realism, rich environmental storytelling, highly detailed surfaces, elegant depth.",
  "width": 1536,
  "height": 1024,
  "seed": 15903,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/64d5f0f7-e107-4e66-b1b2-475363c9825d.jpg",
      "https://assets.runware.ai/assets/inputs/f468cd76-38f7-42d8-9b84-162c6512ddb7.jpg",
      "https://assets.runware.ai/assets/inputs/a9b3eff0-b15e-43e7-9ae7-9482316cbecb.jpg"
    ]
  }
}

Response

{
  "taskType": "imageInference",
  "taskUUID": "95a328fa-7359-4afd-91f9-6fc8d09071b5",
  "imageUUID": "045f8a5d-1974-4822-b1b3-9a04ef9e86f2",
  "imageURL": "https://im.runware.ai/image/os/a21d05/ws/2/ii/045f8a5d-1974-4822-b1b3-9a04ef9e86f2.jpg",
  "seed": 15903,
  "cost": 0.09
}

Text to Image

Submerged Grand Library Atrium

Request

{
  "taskType": "imageInference",
  "taskUUID": "57dfe0a1-910d-4be7-ba1a-bdc5c876e655",
  "model": "bfl:5@1",
  "positivePrompt": "A vast sunken library atrium beneath clear seawater, seen from inside the structure: towering marble arches wrapped in drifting kelp, suspended ladders, floating open books with warped pages, schools of silver fish weaving through shafts of sunlight from a shattered glass ceiling, a circular mosaic floor partly buried in silt, a central reading dais with a toppled globe and brass instruments, tiny air bubbles rising from cracked stone seams, distant rays illuminating dust-like particles in the water, cinematic scale, exquisite texture detail, elegant symmetry, serene abandoned grandeur, natural color palette of teal, ivory, gold, and muted coral, ultra-detailed environment, believable underwater optics, deep perspective, masterful composition",
  "width": 1536,
  "height": 1024,
  "seed": 16070,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  }
}

Response

{
  "taskType": "imageInference",
  "taskUUID": "57dfe0a1-910d-4be7-ba1a-bdc5c876e655",
  "imageUUID": "3d5293e0-50f5-44a9-9784-0136b0795b0c",
  "imageURL": "https://im.runware.ai/image/os/a13d12/ws/3/ii/3d5293e0-50f5-44a9-9784-0136b0795b0c.jpg",
  "seed": 16070,
  "cost": 0.045
}

Image to Image

Tidal Clockwork Harbor Panorama

Request

{
  "taskType": "imageInference",
  "taskUUID": "f897e528-4f85-4abe-9457-3c2dd09ba9ce",
  "model": "bfl:5@1",
  "positivePrompt": "A grand panoramic harbor city built around colossal tidal clockwork, terraced quays, suspended bridges, and cathedral-scale brass mechanisms turning above the waterline; fishing vessels and cargo barges dwarfed by gigantic engraved gears; airborne manta-like creatures circling through bright maritime air; wet cobblestones, salt spray, oxidized metal, canvas sails, carved stone arches, cranes, pulleys, and intricate mechanical details; cinematic wide composition, believable scale, highly detailed textures, atmospheric depth, natural color harmony, crisp focus, masterful environmental storytelling",
  "width": 1536,
  "height": 1024,
  "seed": 27270,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/bdaeb71c-ebf0-49de-b3da-590fae66fb93.jpg",
      "https://assets.runware.ai/assets/inputs/c1d8b027-b1c2-4a58-b50d-72126cef99b7.jpg",
      "https://assets.runware.ai/assets/inputs/94cbc938-56de-4405-8d1a-838a112330fd.jpg"
    ]
  }
}

Response

{
  "taskType": "imageInference",
  "taskUUID": "f897e528-4f85-4abe-9457-3c2dd09ba9ce",
  "imageUUID": "fd294a8f-6df8-454f-838b-a415b804c443",
  "imageURL": "https://im.runware.ai/image/os/a13d12/ws/3/ii/fd294a8f-6df8-454f-838b-a415b804c443.jpg",
  "seed": 27270,
  "cost": 0.09
}

Text to Image

Wind-Carved Salt Cathedral

Request

{
  "taskType": "imageInference",
  "taskUUID": "4dd729da-e356-413b-8e48-794bee98a888",
  "model": "bfl:5@1",
  "positivePrompt": "A monumental cathedral formed entirely from white salt and translucent mineral crystal on a vast dried lakebed, soaring ribbed vaults eroded by centuries of wind, delicate buttresses shaped like frozen waves, long processional path of cracked geometric salt tiles leading to the entrance, tiny robed pilgrims and pack animals for scale, suspended prayer ribbons fluttering between carved arches, airborne salt dust catching angled sunrise light, pale apricot and silver sky after a storm, distant mirage shimmer on the horizon, hyper-detailed textures of crusted salt, carved mineral veins, and weathered surfaces, cinematic wide shot, awe-filled atmosphere, grand sense of scale, masterful depth, crisp focal clarity, realistic volumetric haze, high dynamic range, richly detailed environmental storytelling",
  "width": 1536,
  "height": 1024,
  "seed": 73410,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  }
}

Response

{
  "taskType": "imageInference",
  "taskUUID": "4dd729da-e356-413b-8e48-794bee98a888",
  "imageUUID": "1a3551a7-b095-42a3-8e6e-9fffe584e0f3",
  "imageURL": "https://im.runware.ai/image/os/a25d05/ws/3/ii/1a3551a7-b095-42a3-8e6e-9fffe584e0f3.jpg",
  "seed": 73410,
  "cost": 0.045
}