FLUX 3 Image Klein Base - Unifically

Generate and edit images with FLUX 3 Image Klein Base, the undistilled 5.6B open-weight FLUX 3 checkpoint. It samples at 50 steps by default and adds classifier-free guidance and a negative prompt on top of the same text-to-image, editing and multi-reference route as the distilled model. More on this model: FLUX 3 Image Klein Base API page.

Model

black-forest-labs/flux-3-image-klein-base

Parameters

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	-	Text description of the image, or the edit to apply to the reference images
`negative_prompt`	string	No	`null`	What to keep out of the image. Ignored when `guidance` is `1` or lower
`aspect_ratio`	string	No	`"16:9"`	`"21:9"`, `"16:9"`, `"4:3"`, `"1:1"`, `"3:4"`, `"9:16"`, `"9:21"`
`resolution`	string	No	`"1mp"`	`"0.6mp"`, `"1mp"`, `"2mp"`, `"4mp"`
`image_urls`	string[]	No	`null`	Up to 4 reference image URLs for editing or multi-reference generation
`steps`	integer	No	`50`	Sampling steps, `1`-`50`
`guidance`	float	No	`3.5`	CFG guidance scale, `1`-`20`
`seed`	integer	No	random	Seed for reproducibility
`nsfw_check`	boolean	No	`true`	Check uploaded media inputs for NSFW content

The distilled FLUX 3 Image Klein runs about three times faster at the same size and is the default for production volume. Use Base for guidance experiments and to match LoRAs trained on the Base weights.

Example Request

curl -X POST https://api.unifically.com/v1/tasks   -H "Content-Type: application/json"   -H "Authorization: Bearer YOUR_API_KEY"   -d '{
    "model": "black-forest-labs/flux-3-image-klein-base",
    "input": {
      "prompt": "Studio product shot of a matte black ceramic pour-over coffee dripper on a walnut slab",
      "negative_prompt": "text, watermark, extra objects",
      "aspect_ratio": "16:9",
      "resolution": "1mp",
      "guidance": 3.5
    }
  }'

Response

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "processing"
  }
}

Volume discounts are available for almost all models. Reach out at contact@unifically.com to discuss custom pricing.