GET

/v1/schemas/fal/image/fal-ai%2Ffast-lcm-diffusion

kind inputactivity imagehash aa97dde7extracted Jul 6, 2026version currentsource upstream spec ↗

Request body

13 properties · 1 required · 1 $defs
propertytypedescriptionconstraints
prompt*stringThe prompt to use for generating the image. Be as descriptive as possible for best results.
seedinteger The same seed and the same prompt given to the same version of Stable Diffusion will output the same image every time. nullable
num_imagesintegerThe number of images to generate.1 ≤ n ≤ 8 · default: 1
image_sizeImageSize | enumThe size of the generated image.default: "square_hd"
formatenumThe format of the generated image.jpeg | png · default: "jpeg"
guidance_scalenumberThe CFG (Classifier Free Guidance) scale is a measure of how close you want the model to stick to your prompt when looking for a related image to show you.0 ≤ n ≤ 20 · default: 1.5
num_inference_stepsintegerThe number of inference steps to perform.1 ≤ n ≤ 32 · default: 6
expand_promptbooleanIf set to true, the prompt will be expanded with additional prompts.default: false
safety_checker_versionenumThe version of the safety checker to use. v1 is the default CompVis safety checker. v2 uses a custom ViT model.v1 | v2 · default: "v1"
negative_promptstringThe negative prompt to use. Use it to address details that you don't want in the image. This could be colors, objects, scenery and even the small details (e.g. moustache, blurry, low resolution).default: ""
sync_modebooleanIf `True`, the media will be returned as a data URI and the output data won't be available in the request history.default: true
enable_safety_checkerbooleanIf set to true, the safety checker will be enabled.default: true
request_idstringAn id bound to a request, can be used with response to identify the request itself.default: ""

Validate a payload

before you spend tokens
shell
$ curl -X POST https://modelschemas.com/v1/validate \
    -d '{"provider":"fal","endpointId":"fal-ai/fast-lcm-diffusion","payload":{…}}'
→ {"valid": false, "errors": [{"path": "#", "keyword": "required", …}]}