Image Generation

FLUX 3 Image Klein API

FLUX 3 Image Klein: fast open-weights FLUX 3 for text-to-image and edits with up to 10 reference images, unlimited on Relax. Integrate this model via REST with endpoint docs, parameters, and code examples.

Prompting guide Compare image models Use cases

Img2Img

Editing

Credit Cost

0.5 credits

Type

Image

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API Endpoint

POST

/api/v1/models/flux-3-image-klein/run

Test This Model

Run a real request through the API pipeline and inspect the exact input and output your integration will handle. Uses your credits like any API call; failed runs are refunded automatically.

LLM.txt

AI-Ready

For AI assistants

Copy this model's documentation into Claude, GPT, or any AI for instant integration help.

/llm/flux-3-image-klein.txt

OpenAPI Spec

Swagger compatible

Import into Postman, Swagger UI, or generate client SDKs in any language.

/api/openapi

Parameters

Input parameters accepted by this model

Parameter	Type	Description	Default
`prompt` required	string	What to generate, or the edit to make to the reference images	-
`aspect_ratio`	enum	"auto" matches the first reference image when editing, else 1:1 `auto1:14:33:43:2`+3 more	`auto`
`resolution`	enum	1k (about 1 megapixel, 0.5 credits per image) or 2k (about 4 megapixels, 1 credits per image) `1k2k`	`1k`
`num_images`	integer	Images to generate (1-4) min: 1 \| max: 4	`1`
`reference_images`	array	Up to 10 image URLs to edit or compose from; refer to them as image 1, image 2, ...	-
`prompt_upsampling`	boolean	Expand the prompt into the full scene caption the model is trained on (on by default). Turn it off only when you send a complete caption yourself.	`true`
`seed`	integer	Random seed for reproducibility	-
`output_format`	enum	jpeg, png or webp `jpegpngwebp`	`jpeg`

Use saved characters (@Name)

Write @Name in the prompt to use a character, product, outfit, location, prop or style saved in the account's Character Studio, for example "@Mara on a beach at sunset". Its photos are added to reference_images automatically, after any images you send yourself, so your own image numbering is unchanged. List saved names with GET /api/v1/characters and save new ones with POST /api/v1/characters. An @word that names nothing saved stays plain text.

Supported Aspect Ratios

1:1

4:3

3:4

3:2

2:3

16:9

9:16

Code Examples

Generate with FLUX 3 Image Klein — copy and paste to get started

bash

curl -X POST "https://pixeldojo.ai/api/v1/models/flux-3-image-klein/run" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A ceramicist trimming a bowl on a wheel, late afternoon window light, clay dust in the air",
    "aspect_ratio": "16:9"
  }'

Response Format

Submit Response (202 Accepted)

json

{
  "jobId": "job_abc123...",
  "status": "pending",
  "statusUrl": "https://pixeldojo.ai/api/v1/jobs/job_abc123...",
  "creditCost": 0.5,
  "creditsRemaining": 95,
  "expiresAt": "2026-10-19T03:30:52Z"
}

Completed Response