nbpOpenNode-ComfyUI

A custom ComfyUI node for generating images with Google Gemini image models, authenticated via your ComfyUI Cloud API key — no separate Google API key required.

Node: NBP Gemini Image 2

Generates (and optionally edits) images using Google's Gemini image models through the ComfyUI Vertex AI proxy. Auth is handled automatically by your ComfyUI account credentials.

Inputs

Input	Type	Required	Description
prompt	String	Yes	Describe the image to generate or edits to apply
model	Dropdown	Yes	Gemini model to use (see models below)
seed	Int	Yes	Fixed seed for reproducibility (best-effort)
aspect_ratio	Dropdown	Yes	Output aspect ratio; auto matches the input image
resolution	Dropdown	Yes	1K, 2K, or 4K — 2K/4K use Gemini's native upscaler
temperature	Float	Yes	Controls randomness (0.0–2.0). Lower = more predictable, higher = more creative
top_p	Float	Yes (advanced)	Nucleus sampling threshold (0.0–1.0). Lower = more focused output
top_k	Int	Yes (advanced)	Limits the token pool at each step (1–100). Lower = more deterministic
response_modalities	Dropdown	Yes (advanced)	IMAGE for image only; IMAGE+TEXT also returns model reasoning
images	IMAGE	No	Optional reference image(s) for editing or style guidance (up to 14, use Batch Images node for multiple)
system_prompt	String	No (advanced)	System-level instructions shaping the model's behavior

Outputs

Output	Type	Description
IMAGE	IMAGE	Generated image batch
STRING	STRING	Any text returned alongside the image (empty if IMAGE modality)

Supported models

Model	Notes
gemini-3-pro-image-preview	Highest quality, higher cost
gemini-3.1-flash-image-preview	Fast, lower cost (Nano Banana 2)
gemini-2.5-flash-image-preview	Previous generation preview
gemini-2.5-flash-image	Previous generation stable

Installation

1. Clone or copy this folder into your ComfyUI custom_nodes/ directory:

   custom_nodes/
   └── nbpOpenNode-ComfyUI/
       ├── __init__.py
       └── nbp_gemini_image2.py
   

2. Restart ComfyUI.
3. The node will appear under api node → image → Gemini as NBP Gemini Image 2.

Requirements

No additional packages required — all dependencies ship with ComfyUI.

Authentication

This node uses the ComfyUI Cloud API. You must be logged in to your ComfyUI account within the application. The node will use your account's API key automatically; no separate Google or Vertex AI credentials are needed.