Black Forest LabsMediumHigh

FLUX.2 Dev

Development version of FLUX.2 with image editing capabilities and reference image support. Ideal for iterative design workflows and experimentation.

25 credits

per image

Image editing capabilities

Reference image support

Balanced speed and quality

Great for iterative workflows

Cost-effective for development

Use with AI Assistant

Copy usage instructions for Claude, ChatGPT, or other AI

llms.txt

Quick Start

curl -X POST "https://api.core.today/v1/predictions" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: cdt_your_api_key" \
  -d '{
  "model": "black-forest-labs/flux-2-dev",
  "input": {
    "prompt": "A cozy reading nook with warm lighting, vintage armchair, floor-to-ceiling bookshelves, photorealistic interior design",
    "image_size": "landscape_4_3",
    "num_inference_steps": 28,
    "guidance_scale": 3.5
  }
}'

Parameters

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	-	Text description of the image to generate
`input_images`	array	No	-	Input images for image-to-image generation (max 4)
`go_fast`	boolean	No	-	Run faster predictions with additional optimizations
`aspect_ratio`	string	No	1:1	Aspect ratio for the generated image (use 'match_input_image' to match input) 1:116:99:164:33:4match_input_imagecustom
`seed`	integer	No	-	Random seed for reproducibility
`output_format`	string	No	jpg	Format of the output images pngjpgwebp
`output_quality`	integer	No	80	Quality of output images (0-100)

How to Provide File Input

There are 3 ways to provide files for the input_images parameter:

Recommended

Direct Upload (Multipart)

Attach files directly to POST /v1/predictions/upload. No separate upload step needed.

curl -X POST "https://api.core.today/v1/predictions/upload" \
  -H "X-API-Key: cdt_your_api_key" \
  -F "model=black-forest-labs/flux-2-dev" \
  -F 'input={"prompt":"your prompt here"}' \
  -F "file:input_images=@your_file.png"

Image URL

Pass a publicly accessible URL directly. You can also use file_url from the Storage API.

{
  "model": "black-forest-labs/flux-2-dev",
  "input": {
    "prompt": "your prompt here",
    "input_images": ["https://example.com/image.jpg"]
  }
}

See the File Upload docs for more upload methods including Presigned URLs.

Common Parameters

Common parameters used when calling POST /v1/predictions.

Parameter	Type	Required	Default	Description
`model`	string	Yes	-	Model identifier
`input`	object	Yes	-	Object containing the model-specific parameters from the table above
`output_folder`	string	No	-	Folder path for output files (max 256 chars, '..' not allowed)
`webhook_url`	string	No	-	Webhook URL to call on completion
`is_public`	boolean	No	false	If true, output files are also available via permanent public URLs

Examples

Reference-based Generation

Generate an image guided by a reference

curl -X POST "https://api.core.today/v1/predictions" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: cdt_your_api_key" \
  -d '{
  "model": "black-forest-labs/flux-2-dev",
  "input": {
    "prompt": "A cozy reading nook with warm lighting, vintage armchair, floor-to-ceiling bookshelves, photorealistic interior design",
    "image_size": "landscape_4_3",
    "num_inference_steps": 28,
    "guidance_scale": 3.5
  }
}'