Flux 2 Klein 4B - Image Editor

Fast and cost-efficient text-based image editing by Black Forest Labs. The 4B parameter architecture delivers quick, responsive edits ideal for prototyping and high-throughput 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	Must be IMAGE_EDITOR
model	string	Yes	Must be black-forest-labs/flux-2-klein-4b
promptObject	object	Yes	Configuration object containing all editing parameters

Prompt Object Parameters

Parameter	Type	Required	Description	Default
imageUrl	string	Yes	Asset path of the image to edit (from Asset API)	-
prompt	string	Yes	Text description of the desired edit	-
aspect_ratio	string	No	Output aspect ratio (1:1, 16:9, 9:16, 3:2, 2:3, 4:5, 5:4)	match_input_image
output_format	string	No	Output file format (webp, jpg, png)	webp
output_quality	number	No	Output image quality (0-100)	80
num_inference_steps	number	No	Number of denoising steps (1-50)	28
go_fast	boolean	No	Enable speed-optimized generation	false
megapixels	string	No	Output resolution in megapixels (0.25, 1)	1
disable_safety_checker	boolean	No	Disable built-in safety filtering	false
seed	number	No	Random seed for reproducibility	Random

Code Examples

cURL

curl -X POST "https://api.1min.ai/api/features" \
-H "API-KEY: <api-key>" \
-H "Content-Type: application/json" \
-d '{
  "type": "IMAGE_EDITOR",
  "model": "black-forest-labs/flux-2-klein-4b",
  "promptObject": {
    "imageUrl": "development/images/2025_12_04_18_10_29_882_cat.png",
    "prompt": "Change the shirt color to bright red",
    "num_inference_steps": 20,
    "go_fast": true,
    "output_format": "webp",
    "output_quality": 80
  }
}'

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_EDITOR',
  model: 'black-forest-labs/flux-2-klein-4b',
  promptObject: {
    imageUrl: 'development/images/2025_12_04_18_10_29_882_cat.png',
    prompt: 'Change the shirt color to bright red',
    num_inference_steps: 20,
    go_fast: true,
    output_format: 'webp',
    output_quality: 80
  }
})
})

Python

import requests

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

data = {
"type": "IMAGE_EDITOR",
"model": "black-forest-labs/flux-2-klein-4b",
"promptObject": {
  "imageUrl": "development/images/2025_12_04_18_10_29_882_cat.png",
  "prompt": "Change the shirt color to bright red",
  "num_inference_steps": 20,
  "go_fast": True,
  "output_format": "webp",
  "output_quality": 80
}
}

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

Interactive Playground

API Playground

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

AI Model *Flux 2 Klein 4B - Black Forest Labs

Image URL *

Asset path of the source image to edit

Prompt *

Describe the edit you want to apply

Change the shirt color to bright red

Inference Steps

Number of denoising steps (1-50)

Go Fast TrueFalse

Megapixels 0.25 MP (~512×512)1 MP (~1024×1024)

Output Quality

Output image quality (0-100)

Seed

Random seed for reproducibility

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_EDITOR",
  "model": "black-forest-labs/flux-2-klein-4b",
  "promptObject": {
    "imageUrl": "development/images/2025_12_04_18_10_29_882_cat.png",
    "prompt": "Change the shirt color to bright red",
    "num_inference_steps": 20,
    "go_fast": true,
    "output_format": "webp",
    "output_quality": 80
  }
}'

Response Format

{
"aiRecord": {
  "uuid": "e5f6a7b8-c9d0-1234-efab-345678901234",
  "model": "black-forest-labs/flux-2-klein-4b",
  "type": "IMAGE_EDITOR",
  "status": "SUCCESS",
  "createdAt": "2026-03-27T10:00:00.000Z",
  "aiRecordDetail": {
    "promptObject": {
      "imageUrl": "development/images/2025_12_04_18_10_29_882_cat.png",
      "prompt": "Change the shirt color to bright red",
      "num_inference_steps": 20,
      "go_fast": true,
      "output_format": "webp",
      "output_quality": 80
    },
    "resultObject": [
      "development/images/2026_03_27_10_00_07_001_edited.webp"
    ]
  },
  "temporaryUrl": "https://s3.us-east-1.amazonaws.com/asset.1min.ai/development/images/2026_03_27_10_00_07_001_edited.webp?..."
}
}

Use Cases

• Rapid Prototyping: Quickly iterate on edits during design review cycles
• Color & Texture Swaps: Fast single-attribute edits like color changes
• High-Volume Pipelines: Cost-efficient editing for large batches of images
• Interactive Apps: Low-latency edits for real-time user-facing applications