Black Forest LabsMediumUltra

FLUX Kontext Pro

State-of-the-art text-based image editing model that transforms images through natural language. Excellent for style transfer, object modification, text replacement, background changes, and character consistency.

120 credits

per image

Text-driven image editing with high fidelity

Style transfer and transformation

Object and text replacement

Background editing

Character consistency across edits

Run it right now

Test this model instantly in the Console Playground — no code required

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-kontext-pro",
  "input": {
    "prompt": "Make this a 90s cartoon",
    "input_image": "https://replicate.delivery/pbxt/N55l5TWGh8mSlNzW8usReoaNhGbFwvLeZR3TX1NL4pd2Wtfv/replicate-prediction-f2d25rg6gnrma0cq257vdw2n4c.png",
    "aspect_ratio": "match_input_image",
    "output_format": "jpg",
    "safety_tolerance": 2
  }
}'

Parameters

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	-	Editing instruction or generation prompt
`input_image`	string	No	-	URL of the source image to edit (jpeg, png, gif, or webp)
`aspect_ratio`	string	No	match_input_image	Output aspect ratio. Use match_input_image to preserve the input ratio match_input_image1:116:99:164:33:43:22:34:55:421:99:212:11:2
`output_format`	string	No	png	Output image format jpgpng
`safety_tolerance`	integer	No	2	Safety tolerance: 0 strictest, 6 most permissive. Max 2 when input_image is provided
`prompt_upsampling`	boolean	No	false	Auto-improve prompt before generation
`seed`	integer	No	-	Random seed for reproducibility

How to Provide File Input

There are 3 ways to provide files for the input_image 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-kontext-pro" \
  -F 'input={"prompt":"your prompt here"}' \
  -F "file:input_image=@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-kontext-pro",
  "input": {
    "prompt": "your prompt here",
    "input_image": "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

Style Transfer

Convert a photo into a 90s cartoon style

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-kontext-pro",
  "input": {
    "prompt": "Make this a 90s cartoon",
    "input_image": "https://replicate.delivery/pbxt/N55l5TWGh8mSlNzW8usReoaNhGbFwvLeZR3TX1NL4pd2Wtfv/replicate-prediction-f2d25rg6gnrma0cq257vdw2n4c.png",
    "aspect_ratio": "match_input_image",
    "output_format": "jpg",
    "safety_tolerance": 2
  }
}'