GET
/v1/schemas/fal/image/blackforestlabs/flux-3/klein/text-to-image/lora
Accept:
| field | recorded source |
|---|---|
| schema | Source linked above. upstream-spec Source tracea48af1e18f385f95e673d7b5f0ec0834833c8e87fe6098f4fc0518e3e40959dc{
"fetchedAt": 1793077201,
"extractorVersion": "1",
"verifiedAt": null
} |
Request body
10 properties · 1 required · 4 $defs| property | type | description | constraints |
|---|---|---|---|
| prompt* | string | The prompt to generate an image from. The model is trained on detailed captions: describe framing, subject, background and lighting. | |
| seed | integer | The same seed and the same prompt given to the same version of the model will output the same image every time. | nullable |
| image_size | ImageSize | enum | The size of the generated image. Each side can be 256 to 4096 pixels (native 4K). | default: "square_hd" |
| output_format | enum | The format of the generated image. | jpeg | png | webp · default: "png" |
| loras | LoRAInput[] | LoRA weights to apply (maximum 3). | items ≤ 3 · default: [] |
| num_images | integer | The number of images to generate. | 1 ≤ n ≤ 4 · default: 1 |
| enable_safety_checker | boolean | If set to true, the safety checker will be enabled. | default: true |
| bounding_boxes | BoundingBox[] | 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>`. | items ≤ 32 · nullable |
| sync_mode | boolean | If `True`, the media will be returned as a data URI and the output data won't be available in the request history. | default: false |
| enable_prompt_expansion | boolean | If set to true, the prompt is expanded into a detailed caption (grounded in the reference images when editing) before generation. | default: true |
Types
4 $defsBoundingBoxobject
| description* | string | What to draw in this box: the object and its look. | length ≤ 500 |
| label | string | Short name for the object in this box, e.g. `fox`. Write `<fox>` in the prompt to tie the box to those words; a box the prompt doesn't name is added to the scene. Defaults to `obj_<n>`. | length ≤ 64 · nullable |
| box* | Box | Where the object goes in the output image. |
Boxobject
| x_min* | number | Left edge as a fraction of the image width (0-1). | 0 ≤ n ≤ 1 |
| x_max* | number | Right edge as a fraction of the image width (0-1). | 0 ≤ n ≤ 1 |
| y_max* | number | Bottom edge as a fraction of the image height (0-1). | 0 ≤ n ≤ 1 |
| y_min* | number | Top edge as a fraction of the image height (0-1). | 0 ≤ n ≤ 1 |
ImageSizeobject
| height | integer | The height of the generated image. | 0 < n ≤ 14142 · default: 512 |
| width | integer | The width of the generated image. | 0 < n ≤ 14142 · default: 512 |
LoRAInputobject
| scale | number | Scale factor for LoRA application (0.0 to 4.0). | 0 ≤ n ≤ 4 · default: 1 |
| path* | string | URL to a FLUX 3 Klein LoRA (.safetensors), e.g. from flux-3-image-klein-trainer. |
Validate a payload
before you spend tokensshell
$ curl -X POST https://modelschemas.com/v1/validate \
-d '{"provider":"fal","endpointId":"blackforestlabs/flux-3/klein/text-to-image/lora","payload":{…}}'
→ {"valid": false, "errors": [{"path": "#", "keyword": "required", …}]}