FLUX 3 Klein Image Editing API: AI Image Editor

Edit images with the FLUX 3 Klein API. Send up to 10 reference images, describe the change, and choose 1K, 2K, or 4K outputs. Edit one to ten reference images with Black Forest Labs FLUX 3 Klein using a natural-language instruction. Choose 1K, 2K, or 4K output, automatic or fixed framing, PNG/JPEG/WebP format, prompt enhancement, and up to four results.

Interactive model controls

Edit one to ten reference images with Black Forest Labs FLUX 3 Klein using a natural-language instruction. Choose 1K, 2K, or 4K output, automatic or fixed framing, PNG/JPEG/WebP format, prompt enhancement, and up to four results.

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Overview

About this model

The FLUX 3 Klein image editing API applies a natural-language instruction to one or more reference images. Send up to ten public image URLs, choose automatic or fixed output framing, select 1K, 2K, or 4K resolution, and request up to four results. It gives developers an asynchronous image-edit route with output pricing of $0.009 at 1K, $0.014 at 2K, or $0.036 at 4K per image. See the complete FLUX Klein API catalog, generate new images with FLUX 3 Klein Text to Image, or compare FLUX.2 variants on FLUX.2.

1Product editing: Change backgrounds, colors, or scene details while retaining a reference image.

2Creative revisions: Apply focused natural-language changes to an existing composition.

3Reference-based design: Provide several images to guide a consistent edit.

4Batch variations: Return up to four edits per asynchronous request.

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Pricing & Value

Cost analysis

Provider	Cost	Notes
muapiapp	$0.009 / $0.014 / $0.036 per image (1K / 2K / 4K)	One asynchronous endpoint; total scales with num_images.
Fal.ai	$0.009 / $0.014 / $0.036 per image (1K / 2K / 4K)	Matches the planned pricing schedule shown in the supplied reference screenshot.
Replicate	Not compared	No current like-for-like public rate was verified for this page.

muapiapp$0.009 / $0.014 / $0.036 per image (1K / 2K / 4K)

One asynchronous endpoint; total scales with num_images.

Fal.ai$0.009 / $0.014 / $0.036 per image (1K / 2K / 4K)

Matches the planned pricing schedule shown in the supplied reference screenshot.

ReplicateNot compared

No current like-for-like public rate was verified for this page.

** Competitor pricing is estimated based on similar model architectures and usage tiers.

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Technical Details

Configuration schema

Parameter	Type	Description	Default
Prompt	string	Describe the image or the edit to apply (up to 5,000 characters).	`A sculptural glass perfume bottle on a warm limestone plinth, soft editorial light, crisp product photography.`
Image URLs	array	One to ten public reference image URLs to edit.	`https://example.com/reference.jpg`
Aspect Ratio	Enum (10 options)	Output framing, or auto to preserve source framing.	`auto`
Resolution	Enum (3 options)	Requested output resolution.	`1K`
Output Format	Enum (3 options)	Image encoding for each generated output.	`png`
Number of Images	integer	Number of images to generate (1–4). Price is charged per output image.	`1`
Seed	integer	Optional reproducibility seed.	`-`
Enhance Prompt	boolean	Let the model refine the prompt before generation.	`true`

Promptstring

Describe the image or the edit to apply (up to 5,000 characters).

Default ValueA sculptural glass perfume bottle on a warm limestone plinth, soft editorial light, crisp product photography.

Image URLsarray

One to ten public reference image URLs to edit.

Default Valuehttps://example.com/reference.jpg

Aspect RatioEnum (10 options)

Output framing, or auto to preserve source framing.

Default Valueauto

ResolutionEnum (3 options)

Requested output resolution.

Default Value1K

Output FormatEnum (3 options)

Image encoding for each generated output.

Default Valuepng

Number of Imagesinteger

Number of images to generate (1–4). Price is charged per output image.

Default Value1

Seedinteger

Optional reproducibility seed.

Default Value-

Enhance Promptboolean

Let the model refine the prompt before generation.

Default Valuetrue

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Implementation Guide

Developer documentation

How to Use the FLUX 3 Klein Image Editing API

Prepare reference URLs. Provide one to ten publicly accessible image URLs in images_list.
Describe the edit. Write a clear instruction in prompt. Choose aspect_ratio (auto or a supported ratio), resolution (1K, 2K, or 4K), and the output format. num_images can be from 1 to 4.
Submit and retrieve the result. Pricing is per output image: $0.009 at 1K, $0.014 at 2K, and $0.036 at 4K.

curl -X POST https://api.muapi.ai/api/v1/flux-3-klein-edit-image \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"prompt":"Replace the plain background with a warm limestone studio, preserving the product shape","images_list":["https://example.com/product.jpg"],"resolution":"2K","aspect_ratio":"auto"}'

# Poll the asynchronous task
curl https://api.muapi.ai/api/v1/predictions/REQUEST_ID/result \
  -H "x-api-key: YOUR_API_KEY"

The result contains an outputs array of edited image URLs. For text-only generation, use FLUX 3 Klein Text to Image.

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Common Questions

Frequently asked

How do I edit an image with FLUX 3 Klein?

Call the edit endpoint with a prompt describing the change and one or more public image URLs in `images_list`.

How many reference images can I provide?

Pass 1–10 reference URLs. They need to be accessible to the API while the job runs.

What output resolutions are supported?

The endpoint supports 1K, 2K, and 4K output.

How much does FLUX 3 Klein editing cost?

Muapi charges $0.009 per 1K output image, $0.014 per 2K output image, and $0.036 per 4K output image. Multiply the per-image rate by `num_images`.

Can I preserve the source image framing?

Set `aspect_ratio` to `auto` to let the endpoint use automatic framing. You may also request a supported fixed aspect ratio.