API reference · BFL

bfl/flux-general/rf-inversion

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/rf-inversion

Input Schema

28 parameters · 2 required · 26 optional

Parameter	Type	Required	Description
`image`	string	Required	URL of image to be edited
`prompt`	string	Required	The prompt to edit the image with
`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`	array	Optional	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
`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
`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.
`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: []
`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	Min: 0 · Max: 20 · 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
`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	Min: 1 · Max: 50 · Default: 28
`reference_image_url`	string	Optional	URL of Image for Reference-Only
`reverse_guidance_end`	integer	Optional	Timestep to stop guidance during reverse process. · Default: 8
`reverse_guidance_start`	integer	Optional	Timestep to start guidance during reverse process. · Default: 0
`reverse_guidance_schedule`	string	Optional	Scheduler for applying reverse guidance. · Options: constant, linear_increase, linear_decrease · Default: "constant" constantlinear_increaselinear_decrease
`controller_guidance_forward`	number	Optional	The controller guidance (gamma) used in the creation of structured noise. · Min: 0.01 · Max: 3 · Default: 0.6
`controller_guidance_reverse`	number	Optional	The controller guidance (eta) used in the denoising process.Using values closer to 1 will result in an image closer to input. · Min: 0.01 · Max: 3 · Default: 0.75

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/rf-inversion",
  "image": "https://static.sandbase.ai/examples/bfl/flux-general/rf-inversion/input_image_0.png",
  "loras": [],
  "prompt": "Wearing glasses",
  "nag_end": 0.25,
  "nag_tau": 2.5,
  "max_shift": 1.15,
  "nag_alpha": 0.25,
  "nag_scale": 3,
  "base_shift": 0.5,
  "easycontrols": [],
  "control_loras": [],
  "output_format": "png",
  "reference_end": 1,
  "guidance_scale": 3.5,
  "reference_start": 0,
  "use_beta_schedule": false,
  "reference_strength": 0.65,
  "num_inference_steps": 28,
  "reverse_guidance_end": 8,
  "reverse_guidance_start": 0,
  "reverse_guidance_schedule": "constant",
  "controller_guidance_forward": 0.6,
  "controller_guidance_reverse": 0.75
}'

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

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