> ## Documentation Index
> Fetch the complete documentation index at: https://docs.comfy.org/llms.txt
> Use this file to discover all available pages before exploring further.
# Stability AI Stable Diffusion 3.5 - ComfyUI Native Node Documentation
> A node that generates high-quality images using Stability AI Stable Diffusion 3.5 model
The Stability AI Stable Diffusion 3.5 Image node uses Stability AI's Stable Diffusion 3.5 API to generate high-quality images. It supports both text-to-image and image-to-image generation, capable of creating detailed visual content from text prompts.
## Parameters
### Required Parameters
| Parameter | Type | Default | Description |
| ------------- | ------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| prompt | string | "" | What you want to see in the output image. Strong, descriptive prompts that clearly define elements, colors and themes will yield better results |
| model | select | - | Choose which Stability SD 3.5 model to use |
| aspect\_ratio | select | "1:1" | Width to height ratio of generated image |
| style\_preset | select | "None" | Optional preset style for the desired image |
| cfg\_scale | float | 4.0 | How strictly the diffusion process adheres to the prompt text (higher values keep your image closer to your prompt). Range: 1.0 - 10.0, Step: 0.1 |
| seed | integer | 0 | Random seed for noise generation (0-4294967294) |
### Optional Parameters
| Parameter | Type | Default | Description |
| ---------------- | ------ | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| image | image | - | Input image. When provided, the node switches to image-to-image mode |
| negative\_prompt | string | "" | Keywords of what you don't want to see in the output image. This is an advanced feature |
| image\_denoise | float | 0.5 | Denoising strength for input image. 0.0 yields image identical to input, 1.0 is as if no image was provided at all. Range: 0.0 - 1.0, Step: 0.01. Only effective when image is provided |
### Output
| Output | Type | Description |
| ------ | ----- | --------------- |
| IMAGE | image | Generated image |
## Usage Example
Stability AI Stable Diffusion 3.5 Image Workflow Example
## Notes
* When an input image is provided, the node switches from text-to-image mode to image-to-image mode
* In image-to-image mode, aspect ratio parameters are ignored
* Mode selection automatically switches based on whether an image is provided:
* No image provided: text-to-image mode
* Image provided: image-to-image mode
* If style\_preset is set to "None", no preset style will be applied
## Source Code
\[Node source code (Updated on 2025-05-07)]
```python theme={null}
class StabilityStableImageSD_3_5Node:
"""
Generates images synchronously based on prompt and resolution.
"""
RETURN_TYPES = (IO.IMAGE,)
DESCRIPTION = cleandoc(__doc__ or "") # Handle potential None value
FUNCTION = "api_call"
API_NODE = True
CATEGORY = "api node/image/Stability AI"
@classmethod
def INPUT_TYPES(s):
return {
"required": {
"prompt": (
IO.STRING,
{
"multiline": True,
"default": "",
"tooltip": "What you wish to see in the output image. A strong, descriptive prompt that clearly defines elements, colors, and subjects will lead to better results."
},
),
"model": ([x.value for x in Stability_SD3_5_Model],),
"aspect_ratio": ([x.value for x in StabilityAspectRatio],
{
"default": StabilityAspectRatio.ratio_1_1,
"tooltip": "Aspect ratio of generated image.",
},
),
"style_preset": (get_stability_style_presets(),
{
"tooltip": "Optional desired style of generated image.",
},
),
"cfg_scale": (
IO.FLOAT,
{
"default": 4.0,
"min": 1.0,
"max": 10.0,
"step": 0.1,
"tooltip": "How strictly the diffusion process adheres to the prompt text (higher values keep your image closer to your prompt)",
},
),
"seed": (
IO.INT,
{
"default": 0,
"min": 0,
"max": 4294967294,
"control_after_generate": True,
"tooltip": "The random seed used for creating the noise.",
},
),
},
"optional": {
"image": (IO.IMAGE,),
"negative_prompt": (
IO.STRING,
{
"default": "",
"forceInput": True,
"tooltip": "Keywords of what you do not wish to see in the output image. This is an advanced feature."
},
),
"image_denoise": (
IO.FLOAT,
{
"default": 0.5,
"min": 0.0,
"max": 1.0,
"step": 0.01,
"tooltip": "Denoise of input image; 0.0 yields image identical to input, 1.0 is as if no image was provided at all.",
},
),
},
"hidden": {
"auth_token": "AUTH_TOKEN_COMFY_ORG",
},
}
def api_call(self, model: str, prompt: str, aspect_ratio: str, style_preset: str, seed: int, cfg_scale: float,
negative_prompt: str=None, image: torch.Tensor = None, image_denoise: float=None,
auth_token=None):
validate_string(prompt, strip_whitespace=False)
# prepare image binary if image present
image_binary = None
mode = Stability_SD3_5_GenerationMode.text_to_image
if image is not None:
image_binary = tensor_to_bytesio(image, total_pixels=1504*1504).read()
mode = Stability_SD3_5_GenerationMode.image_to_image
aspect_ratio = None
else:
image_denoise = None
if not negative_prompt:
negative_prompt = None
if style_preset == "None":
style_preset = None
files = {
"image": image_binary
}
operation = SynchronousOperation(
endpoint=ApiEndpoint(
path="/proxy/stability/v2beta/stable-image/generate/sd3",
method=HttpMethod.POST,
request_model=StabilityStable3_5Request,
response_model=StabilityStableUltraResponse,
),
request=StabilityStable3_5Request(
prompt=prompt,
negative_prompt=negative_prompt,
aspect_ratio=aspect_ratio,
seed=seed,
strength=image_denoise,
style_preset=style_preset,
cfg_scale=cfg_scale,
model=model,
mode=mode,
),
files=files,
content_type="multipart/form-data",
auth_token=auth_token,
)
response_api = operation.execute()
if response_api.finish_reason != "SUCCESS":
raise Exception(f"Stable Diffusion 3.5 Image generation failed: {response_api.finish_reason}.")
image_data = base64.b64decode(response_api.image)
returned_image = bytesio_to_image_tensor(BytesIO(image_data))
return (returned_image,)
```