Flux Fill Dev - Image Mask Editor

Professional AI-powered mask-based image editing model by Black Forest Labs. Flux Fill Dev delivers high-quality inpainting with balanced performance, advanced prompt following, and comprehensive customization options 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-dev
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	-
num_inference_steps	number	No	Number of inference steps (1-50)	28
guidance	number	No	Guidance scale for prompt adherence (0-50)	3.5
seed	number	No	Random seed for reproducibility (0-4294967295)	Random
output_quality	number	No	Output image quality (0-100)	80
disable_safety_checker	boolean	No	Disable built-in safety filtering	false
megapixels	string	No	Output resolution in megapixels (1)	1

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

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-dev",
"promptObject": {
  "imageUrl": "development/images/2025_02_16_15_35_49_260_banana.jpg",
  "maskUrl": "development/images/2025_02_16_15_36_38_743_image.png",
  "prompt": "a ripe red apple with glossy skin and natural lighting",
  "num_inference_steps": 28,
  "guidance": 3.5,
  "megapixels": "1",
  "output_quality": 85
}
}'

JavaScript

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-dev',
  promptObject: {
    imageUrl: 'development/images/2025_02_16_15_35_49_260_banana.jpg',
    maskUrl: 'development/images/2025_02_16_15_36_38_743_image.png',
    prompt: 'a ripe red apple with glossy skin and natural lighting',
    num_inference_steps: 28,
    guidance: 3.5,
    megapixels: '1',
    output_quality: 85
  }
})
})

Python

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-dev",
"promptObject": {
  "imageUrl": "development/images/2025_02_16_15_35_49_260_banana.jpg",
  "maskUrl": "development/images/2025_02_16_15_36_38_743_image.png",
  "prompt": "a ripe red apple with glossy skin and natural lighting",
  "num_inference_steps": 28,
  "guidance": 3.5,
  "megapixels": "1",
  "output_quality": 85
}
}

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

Interactive Playground

API Playground

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

AI Model *Flux Fill Dev - Black Forest Labs

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

a ripe red apple with glossy skin and natural lighting

Num Inference Steps

Number of inference steps (1-50)

Guidance

Guidance scale for prompt adherence (0-50)

Megapixels

Output resolution in megapixels

1 MP (~1024×1024)

Disable Safety Checker

Disable built-in safety filtering

Output Quality

Output image quality (0-100)

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-dev",
  "promptObject": {
    "imageUrl": "development/images/2025_02_16_15_35_49_260_banana.jpg",
    "maskUrl": "development/images/2025_02_16_15_36_38_743_image.png",
    "prompt": "a ripe red apple with glossy skin and natural lighting",
    "num_inference_steps": 28,
    "guidance": 3.5,
    "megapixels": "1",
    "output_quality": 85
  }
}'

Response Format

{
"aiRecord": {
  "uuid": "f1l2d3v4-e5d6-7890-abcd-ef1234567890",
  "userId": "user-12345",
  "teamId": "team-67890",
  "model": "black-forest-labs/flux-fill-dev",
  "type": "IMAGE_INPAINTER",
  "status": "SUCCESS",
  "createdAt": "2025-01-15T16:30:00.000Z",
  "aiRecordDetail": {
    "promptObject": {
      "imageUrl": "development/images/2025_02_16_15_35_49_260_banana.jpg",
      "maskUrl": "development/images/2025_02_16_15_36_38_743_image.png",
      "prompt": "a ripe red apple with glossy skin and natural lighting",
      "num_inference_steps": 28,
      "guidance": 3.5,
      "megapixels": "1",
      "output_quality": 85
    },
    "resultObject": [
      "development/images/2025_01_15_16_30_45_001_flux_fill_dev_edited.png"
    ],
    "responseObject": {}
  },
  "temporaryUrl": "https://s3.us-east-1.amazonaws.com/asset.1min.ai/development/images/2025_01_15_16_30_45_001_flux_fill_dev_edited.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&..."
}
}

Use Cases

• Professional Photo Editing: High-quality image editing for commercial and creative projects
• Product Photography: Enhance product images with professional-grade inpainting
• Content Creation: Create marketing materials and visual assets with precise control
• Artistic Enhancement: Transform and improve images with advanced AI capabilities
• Rapid Prototyping: Fast generation for creative workflows and iterative design

Tips for Best Results

1. Prompt Engineering:

   • Use descriptive, specific language for better results
   • Include style keywords (e.g., "photorealistic", "artistic", "natural lighting")
   • Specify texture, material, and lighting details

2. Quality vs Speed:

   • Higher inference steps (35-50) for maximum quality
   • Lower steps (15-25) for faster generation

3. Mask-based Editing:

   • Use prompt strength 0.6-0.8 for balanced integration
   • Higher guidance (4-6) maintains more context consistency
   • Lower prompt strength preserves original composition better

Notes

Professional Quality

Flux Fill Dev provides an optimal balance of speed and quality for mask-based image editing, making it ideal for professional workflows that require consistent, high-quality results with comprehensive parameter control.