Flux Fill Pro - Image Mask Editor

Premium AI-powered mask-based image editing model by Black Forest Labs. Flux Fill Pro delivers the highest quality inpainting with advanced prompt understanding, superior detail generation, and enterprise-grade reliability for professional image editing workflows.

Endpoint

POSThttps://api.1min.ai/api/features

Request Headers

Field	Value
API-KEY	`<api-key>`
Content-Type	`application/json`

Parameters

Parameter	Type	Required	Description
`type`	string	Yes	Feature type identifier. Must be `IMAGE_INPAINTER`
`model`	string	Yes	AI model identifier. Must be `black-forest-labs/flux-fill-pro`
`promptObject`	object	Yes	Configuration object containing all editing parameters

Prompt Object Parameters

Parameter	Type	Required	Description	Default
`imageUrl`	string	Yes	Path to the source image to be edited	-
`maskUrl`	string	Yes	Path to the mask image defining areas to edit (white=edit, black=preserve)	-
`prompt`	string	Yes	Description of what to generate in the masked areas	-
`outpaint`	string	No	Outpainting mode setting	`None`
`steps`	number	No	Number of inference steps (1-50)	50
`prompt_upsampling`	boolean	No	Enable prompt upsampling for enhanced detail	false
`guidance`	number	No	Guidance scale for prompt adherence (0-100)	60
`safety_tolerance`	number	No	Safety tolerance level (0-6)	3
`output_format`	string	No	Output format for the processed image	`jpg`
`seed`	number	No	Random seed for reproducibility (0-4294967295)	Random

Mask Requirements

Requirement	Description
Format	PNG, JPEG, or WebP formats supported
Dimensions	Must match the source image dimensions exactly
Color Scheme	White areas = regions to edit, Black areas = regions to preserve
Grayscale Support	Gray values for partial editing/blending effects

Code Examples

cURL
JavaScript
Python

curl --location 'https://api.1min.ai/api/features' \
--header 'API-KEY: <api-key>' \
--header 'Content-Type: application/json' \
--data '{
"type": "IMAGE_INPAINTER",
"model": "black-forest-labs/flux-fill-pro",
"promptObject": {
  "imageUrl": "development/images/2025_10_27_10_01_47_241_living_room.png",
  "maskUrl": "development/images/2025_10_27_10_02_04_290_image.png",
  "prompt": "a modern minimalist sofa with clean lines and neutral fabric",
  "outpaint": "None",
  "steps": 50,
  "prompt_upsampling": true,
  "guidance": 60,
  "safety_tolerance": 3,
  "output_format": "jpg"
}
}'

fetch('https://api.1min.ai/api/features', {
method: 'POST',
headers: {
  'Content-Type': 'application/json',
  'API-KEY': 'YOUR_API_KEY'
},
body: JSON.stringify({
  type: 'IMAGE_INPAINTER',
  model: 'black-forest-labs/flux-fill-pro',
  promptObject: {
    imageUrl: 'development/images/2025_10_27_10_01_47_241_living_room.png',
    maskUrl: 'development/images/2025_10_27_10_02_04_290_image.png',
    prompt: 'a modern minimalist sofa with clean lines and neutral fabric',
    outpaint: 'None',
    steps: 50,
    prompt_upsampling: true,
    guidance: 60,
    safety_tolerance: 3,
    output_format: 'jpg'
  }
})
})

import requests

url = "https://api.1min.ai/api/features"
headers = {
"Content-Type": "application/json",
"API-KEY": "YOUR_API_KEY"
}

data = {
"type": "IMAGE_INPAINTER",
"model": "black-forest-labs/flux-fill-pro",
"promptObject": {
  "imageUrl": "development/images/2025_10_27_10_01_47_241_living_room.png",
  "maskUrl": "development/images/2025_10_27_10_02_04_290_image.png",
  "prompt": "a modern minimalist sofa with clean lines and neutral fabric",
  "outpaint": "None",
  "steps": 50,
  "prompt_upsampling": True,
  "guidance": 60,
  "safety_tolerance": 3,
  "output_format": "jpg"
}
}

response = requests.post(url, headers=headers, json=data)

Interactive Playground

API Playground

https://api.1min.ai/api/features

AI Model *

Source Image URL *

Path to the source image to be edited

Mask Image URL *

Path to the mask image (white areas will be edited)

Edit Prompt *

Describe what you want to generate in the masked areas

Outpaint

Outpainting mode setting

Steps

Number of inference steps (1-50)

Prompt Upsampling

Enable prompt upsampling for enhanced detail

Guidance

Guidance scale for prompt adherence (0-100)

Safety Tolerance

Safety tolerance level (0-6, higher = more permissive)

Output Format

Format of the output image

Seed

Random seed for reproducibility (0-4294967295)

Generated cURL Command:

curl -X POST "https://api.1min.ai/api/features" \
  -H "API-KEY: <your-api-key>" \
  -H "Content-Type: application/json" \
  -d '{
  "type": "IMAGE_INPAINTER",
  "model": "black-forest-labs/flux-fill-pro",
  "promptObject": {
    "imageUrl": "development/images/2025_10_27_10_01_47_241_living_room.png",
    "maskUrl": "development/images/2025_10_27_10_02_04_290_image.png",
    "prompt": "a modern minimalist sofa with clean lines and neutral fabric",
    "outpaint": "None",
    "steps": 50,
    "prompt_upsampling": true,
    "guidance": 60,
    "safety_tolerance": 3,
    "output_format": "jpg"
  }
}'

Response Format

{
"aiRecord": {
  "uuid": "f1l2p3r4-o5e6-7890-abcd-ef1234567890",
  "userId": "user-12345",
  "teamId": "team-67890",
  "model": "black-forest-labs/flux-fill-pro",
  "type": "IMAGE_INPAINTER",
  "status": "SUCCESS",
  "createdAt": "2025-01-15T17:00:00.000Z",
  "aiRecordDetail": {
    "promptObject": {
      "imageUrl": "development/images/2025_10_27_10_01_47_241_living_room.png",
      "maskUrl": "development/images/2025_10_27_10_02_04_290_image.png",
      "prompt": "a modern minimalist sofa with clean lines and neutral fabric",
      "outpaint": "None",
      "steps": 50,
      "prompt_upsampling": true,
      "guidance": 60,
      "safety_tolerance": 3,
      "output_format": "jpg"
    },
    "resultObject": [
      "development/images/2025_01_15_17_00_45_001_flux_fill_pro_edited.png"
    ],
    "responseObject": {}
  },
  "temporaryUrl": "https://s3.us-east-1.amazonaws.com/asset.1min.ai/development/images/2025_01_15_17_00_45_001_flux_fill_pro_edited.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&..."
}
}

Use Cases

Enterprise Image Editing: Premium quality editing for high-end commercial projects
Professional Photography: Studio-grade inpainting for fashion, product, and portrait photography
Advertising & Marketing: Premium visual content for luxury brands and high-budget campaigns
Print Media: High-resolution editing for magazines, catalogs, and large-format printing
Fine Art Restoration: Museum-quality inpainting for art restoration and archival work
Film & Entertainment: Professional-grade visual effects and post-production editing

Tips for Best Results

Premium Prompt Engineering:
- Use highly descriptive, professional language
- Include specific technical details (lighting, materials, textures)
- Reference professional photography terms for optimal results
- Specify exact visual qualities and artistic styles
Professional Quality Settings:
- Use 40-50 steps for premium quality results
- Set guidance between 50-70 for optimal Pro performance
- Enable prompt_upsampling for enhanced detail generation
- Use appropriate safety_tolerance (2-4) for professional content
Advanced Mask-based Editing:
- Higher guidance (60-80) maintains professional consistency
- Leverage Pro's advanced context understanding for complex scenes
- Use prompt_upsampling for intricate detail requirements
Enterprise Workflow Optimization:
- Choose appropriate output_format based on use case (jpg for web, png for transparency)
- Consistent seed values for reproducible results
- Adjust safety_tolerance based on content requirements

Mask Creation Tools

Recommended Tools for Professional Masks

Adobe Photoshop: Industry-standard with advanced selection and masking tools
GIMP: Free alternative with comprehensive masking capabilities
Canva: User-friendly online tool for basic mask creation
Paint.NET: Windows-based tool with good selection features
Procreate: iPad app excellent for precise digital masking

Mask Quality Checklist

✅ Exact Dimensions: Mask matches source image size perfectly
✅ High Contrast: Clear distinction between edit areas (white) and preserve areas (black)
✅ Clean Boundaries: Smooth, well-defined edges around objects
✅ Appropriate Coverage: All target areas properly marked for editing
✅ Edge Quality: Suitable edge treatment (hard or soft) for the editing type

Endpoint​

Request Headers​

Parameters​

Prompt Object Parameters​

Mask Requirements​

Code Examples​

Interactive Playground​