falText to imageComing soon

blackforestlabs/flux-3/klein/text-to-image

Name: blackforestlabs/flux-3/klein/text-to-image
Brand: fal

blackforestlabs/flux-3/klein/text-to-image is a text to image tool from fal that runs in the background and returns images. Coming soon: listed with its price, not yet open to runs.

This tool is listed but not yet available to run.

Priced by usage

Pricing

$0.0117 per megapixel. Each image_size preset counts as 1 MP, and a custom width × height rounds up to whole megapixels. Billed on num_images, default 1. The final charge comes from usage.

Limits

Runs: In the background
Returns: image
Longest queue wait: 3600s
Run deadline: 1800s
Largest inline input: 1024 KB
Largest input file: 500 MB
Largest output: 4768 MB
Outputs per run: 16

Input

Field	Kind	Default	Description
`prompt` required	text	—	The prompt to generate an image from. The model is trained on detailed captions: describe framing, subject, background and lighting.
`enable_prompt_expansion`	true or false	true	If set to true, the prompt is expanded into a detailed caption (grounded in the reference images when editing) before generation.
`seed`	number (whole)	—	The same seed and the same prompt given to the same version of the model will output the same image every time.
`num_images`	number (whole) 1 to 4	1	The number of images to generate.
`output_format`	one of jpeg, png, webp	png	The format of the generated image.
`image_size`	JSON	square_hd	The size of the generated image. Each side can be 256 to 4096 pixels (native 4K).
`bounding_boxes`	JSON	—	Optional layout: draw each described object inside its box. Box edges are fractions of the image size, with (0, 0) at the top-left. Name boxes in the prompt by label, e.g. `A red fox <fox> sits under a red umbrella <umbrella>`.

Same request in code

curl https://api.spiral.ai/v1/runs \
  -H "Authorization: Bearer $SPIRAL_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "provider": "fal",
    "model": "blackforestlabs/flux-3/klein/text-to-image",
    "input": {
      "prompt": "A red fox standing in fresh snow at sunrise, its breath visible in the cold air. Soft golden light rakes across the snowfield from the left, pine forest softly…"
    }
  }'