Flux Fill Dev

Playground

FLUX.1 Fill [dev] is a 12 billion parameter rectified flow transformer capable of filling areas in existing images based on a text description.

Features

FLUX.1 Fill [dev]

FLUX.1 Fill [dev] is a 12 billion parameter rectified flow transformer capable of filling areas in existing images based on a text description.

Key Features

Cutting-edge output quality, second only to our state-of-the-art model FLUX.1 Fill [pro].
Blends impressive prompt following with completing the structure of your source image.
Trained using guidance distillation, making FLUX.1 Fill [dev] more efficient.
Open weights to drive new scientific research, and empower artists to develop innovative workflows.

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result


# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-fill-dev" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
    "image": "https://d1q70pf5vjeyhc.wavespeed.ai/media/images/1751357867623574305_6mvrnjgd.png",
    "mask_image": "https://d1q70pf5vjeyhc.wavespeed.ai/media/images/1751257914285280147_ACPNKFCy.png",
    "prompt": "A white translucent silk scarf is wrapped around the neck and flutters in the wind.",
    "size": "1024*1024",
    "num_inference_steps": 28,
    "seed": 0,
    "guidance_scale": 30,
    "num_images": 1,
    "loras": [],
    "enable_safety_checker": true
}'

# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"

Parameters

Task Submission Parameters

Request Parameters

Parameter	Type	Required	Default	Range	Description
image	string	Yes		-	The URL of the image to generate an image from.
mask_image	string	Yes		-	The URL of the mask image to generate an image from.
prompt	string	No		-	The prompt to generate an image from.
size	string	No	1024*1024	256 ~ 1536 per dimension	The size of the generated media in pixels (width*height).
num_inference_steps	integer	No	28	1 ~ 50	The number of inference steps to perform.
seed	integer	No	-	-1 ~ 2147483647	The random seed to use for the generation.
guidance_scale	number	No	30	28 ~ 35	The guidance scale to use for the generation.
num_images	integer	No	1	1 ~ 4	The number of images to generate.
loras	array	No		max 3 items	List of LoRAs to apply (max 3).
loras[].path	string	Yes	-		Path to the LoRA model
loras[].scale	float	Yes	-	0.0 ~ 4.0	Scale of the LoRA model
enable_safety_checker	boolean	No	true	-	If set to true, the safety checker will be enabled.

Response Parameters

Parameter	Type	Description
code	integer	HTTP status code (e.g., 200 for success)
message	string	Status message (e.g., “success”)
data.id	string	Unique identifier for the prediction, Task Id
data.model	string	Model ID used for the prediction
data.outputs	array	Array of URLs to the generated content (empty when status is not `completed`)
data.urls	object	Object containing related API endpoints
data.urls.get	string	URL to retrieve the prediction result
data.has_nsfw_contents	array	Array of boolean values indicating NSFW detection for each output
data.status	string	Status of the task: `created`, `processing`, `completed`, or `failed`
data.created_at	string	ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.error	string	Error message (empty if no error occurred)
data.timings	object	Object containing timing details
data.timings.inference	integer	Inference time in milliseconds

Result Query Parameters

Result Request Parameters

Parameter	Type	Required	Default	Description
id	string	Yes	-	Task ID

Result Response Parameters

Parameter	Type	Description
code	integer	HTTP status code (e.g., 200 for success)
message	string	Status message (e.g., “success”)
data	object	The prediction data object containing all details
data.id	string	Unique identifier for the prediction, the ID of the prediction to get
data.model	string	Model ID used for the prediction
data.outputs	array	Array of URLs to the generated content (empty when status is not `completed`)
data.urls	object	Object containing related API endpoints
data.urls.get	string	URL to retrieve the prediction result
data.has_nsfw_contents	array	Array of boolean values indicating NSFW detection for each output
data.status	string	Status of the task: `created`, `processing`, `completed`, or `failed`
data.created_at	string	ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.error	string	Error message (empty if no error occurred)
data.timings	object	Object containing timing details
data.timings.inference	integer	Inference time in milliseconds

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