Liquid Postman (Gemini Image)
A ComfyUI custom node for image generation using the Google Gemini API. Supports text prompts, image editing, PDF/DOCX file input, and search grounding.
Installation
ComfyUI Manager
Search for "Liquid Postman" in ComfyUI Manager and click Install.
CLI
comfy node install comfyui-liquidpostman
Manual
Clone this repository into your ComfyUI custom_nodes folder:
cd ComfyUI/custom_nodes
git clone https://github.com/majdsalim/ComfyUI-LiquidPostman.git
pip install requests Pillow
Setup
- Get a Gemini API key from Google AI Studio
- Add the Liquid Postman (Gemini Image) node to your workflow (found under
google/gemini) - Paste your API key into the
api_keyfield
Inputs
| Input | Type | Default | Description |
|---|---|---|---|
api_key |
STRING | "" |
Your Gemini API key (required) |
prompt |
STRING | "" |
Text prompt for image generation |
model |
STRING | gemini-3.1-flash-image-preview |
Gemini model to use |
seed |
INT | 42 |
Random seed (-1 to disable) |
aspect_ratio |
ENUM | 1:1 |
Output aspect ratio (1:1, 2:3, 3:2, 3:4, 4:3, 9:16, 16:9, 21:9) |
resolution |
ENUM | 1K |
Output resolution (1K, 2K, 4K) |
response_modalities |
ENUM | IMAGE |
IMAGE or IMAGE+TEXT |
system_prompt |
STRING | (built-in) | System instruction for the model |
search_grounding |
BOOLEAN | false |
Enable Google Search grounding |
files |
STRING | "" |
PDF/DOCX file paths or folder paths (comma or newline separated) |
debug |
BOOLEAN | false |
Print request/response details to console |
images |
IMAGE | (optional) | Input images for editing or reference |
Outputs
| Output | Type | Description |
|---|---|---|
image |
IMAGE | Generated image(s) as a tensor batch |
text |
STRING | Text response from the model (when using IMAGE+TEXT mode) |
Features
Image Generation
Enter a text prompt to generate images with Gemini.
Image Editing
Connect input images to the images pin. All images are uploaded via the Gemini Files API, so there is no file size limit.
File Input (PDF / DOCX)
Provide file paths in the files field. You can:
- List individual file paths separated by commas or newlines
- Provide a folder path to automatically include all
.pdfand.docxfiles in that folder
C:\docs\report.pdf, C:\docs\brief.docx
C:\docs\project_files
Search Grounding
Enable search_grounding to let Gemini use Google Search for up-to-date information when generating images.
Debug Mode
Enable debug to print the full API request body and response metadata to the ComfyUI console.
License
MIT