API reference · BFL

bfl/flux-general/inpainting

Integrate this model through SandBase's unified API, with production-ready schemas and examples.

IMAGEAsyncOpen model

Production endpoint

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OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDbfl/flux-general/inpainting

Input Schema

32 parameters · 2 required · 30 optional

Parameter	Type	Required	Description
`image`	string	Required	URL of image to use for inpainting. or img2img
`prompt`	string	Required	The prompt to generate an image from.
`mask`	string	Optional	The mask to area to Inpaint in.
`seed`	integer	Optional	The same seed and the same prompt given to the same version of the model will output the same image every time.
`loras`	object[]	Optional	The LoRAs to use for the image generation. You can use any number of LoRAs and they will be merged together to generate the final image. · Default: []
`nag_end`	number	Optional	The proportion of steps to apply NAG. After the specified proportion of steps has been iterated, the remaining steps will use original attention processors in FLUX. · Max: 1 · Default: 0.25
`nag_tau`	number	Optional	The tau for NAG. Controls the normalization of the hidden state. Higher values will result in a less aggressive normalization, but may also lead to unexpected changes with respect to the original image. Not recommended to change this value. · Default: 2.5
`strength`	number	Optional	The strength to use for inpainting/image-to-image. Only used if the image_url is provided. 1.0 is completely remakes the image while 0.0 preserves the original. · Min: 0.01 · Max: 1 · Default: 0.85
`max_shift`	number	Optional	Max shift for the scheduled timesteps · Min: 0.01 · Max: 5 · Default: 1.15
`nag_alpha`	number	Optional	The alpha value for NAG. This value is used as a final weighting factor for steering the normalized guidance (positive and negative prompts) in the direction of the positive prompt. Higher values will result in less steering on the normalized guidance where lower values will result in considering the positive prompt guidance more. · Max: 1 · Default: 0.25
`nag_scale`	number	Optional	The scale for NAG. Higher values will result in a image that is more distant to the negative prompt. · Max: 10 · Default: 3
`scheduler`	string	Optional	Scheduler for the denoising process. · Options: euler, dpmpp_2m · Default: "euler" eulerdpmpp_2m
`base_shift`	number	Optional	Base shift for the scheduled timesteps · Min: 0.01 · Max: 5 · Default: 0.5
`fill_image`	string	Optional	Use an image input to influence the generation. Can be used to fill images in masked areas.
`controlnets`	object[]	Optional	The controlnets to use for the image generation. Only one controlnet is supported at the moment. · Default: []
`ip_adapters`	object[]	Optional	IP-Adapter to use for image generation. · Default: []
`aspect_ratio`	string	Optional	The aspect ratio of the generated image. · Options: 21:9, 16:9, 3:2, 4:3, 5:4, 1:1, 4:5, 3:4, 2:3, 9:16 21:916:93:24:35:41:14:53:42:39:16
`easycontrols`	object[]	Optional	EasyControl Inputs to use for image generation. · Default: []
`use_cfg_zero`	boolean	Optional	Uses CFG-zero init sampling as in https://arxiv.org/abs/2503.18886. · Default: false
`use_real_cfg`	boolean	Optional	Uses classical CFG as in SD1.5, SDXL, etc. Increases generation times and price when set to be true. If using XLabs IP-Adapter v1, this will be turned on!. · Default: false
`control_loras`	object[]	Optional	The LoRAs to use for the image generation which use a control image. You can use any number of LoRAs and they will be merged together to generate the final image. · Default: []
`output_format`	string	Optional	The format of the generated image. · Options: jpeg, png · Default: "png" jpegpng
`reference_end`	number	Optional	The percentage of the total timesteps when the reference guidance is to be ended. · Min: 0 · Max: 1 · Default: 1
`guidance_scale`	number	Optional	The 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. · Min: 0 · Max: 20 · Default: 3.5
`real_cfg_scale`	number	Optional	The 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. · Min: 0 · Max: 5 · Default: 3.5
`sigma_schedule`	string	Optional	Sigmas schedule for the denoising process.
`reference_start`	number	Optional	The percentage of the total timesteps when the reference guidance is to bestarted. · Min: 0 · Max: 1 · Default: 0
`controlnet_unions`	object[]	Optional	The controlnet unions to use for the image generation. Only one controlnet is supported at the moment. · Default: []
`use_beta_schedule`	boolean	Optional	Specifies whether beta sigmas ought to be used. · Default: false
`reference_strength`	number	Optional	Strength of reference_only generation. Only used if a reference image is provided. · Min: -3 · Max: 3 · Default: 0.65
`num_inference_steps`	integer	Optional	The number of inference steps to perform. · Min: 1 · Max: 50 · Default: 28
`reference_image_url`	string	Optional	URL of Image for Reference-Only

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

# Step 1: Submit
curl -X POST https://api.sandbase.ai/v1/run \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
  "model": "bfl/flux-general/inpainting",
  "mask": "https://static.sandbase.ai/examples/bfl/flux-general/inpainting/input_mask_1.png",
  "image": "https://raw.githubusercontent.com/CompVis/latent-diffusion/main/data/inpainting_examples/overture-creations-5sI6fQgYIuo.png",
  "loras": [],
  "prompt": "A photo of a lion sitting on a stone bench",
  "nag_end": 0.25,
  "nag_tau": 2.5,
  "strength": 0.85,
  "max_shift": 1.15,
  "nag_alpha": 0.25,
  "nag_scale": 3,
  "scheduler": "euler",
  "base_shift": 0.5,
  "controlnets": [],
  "ip_adapters": [],
  "easycontrols": [],
  "use_cfg_zero": false,
  "use_real_cfg": false,
  "control_loras": [],
  "output_format": "png",
  "reference_end": 1,
  "guidance_scale": 3.5,
  "real_cfg_scale": 3.5,
  "reference_start": 0,
  "controlnet_unions": [],
  "use_beta_schedule": false,
  "reference_strength": 0.65,
  "num_inference_steps": 28
}'

# Step 2: Poll result (replace <id>)
curl https://api.sandbase.ai/v1/run/<id> \
  -H "Authorization: Bearer YOUR_API_KEY"

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