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

1. Get a Gemini API key from Google AI Studio
2. Add the Liquid Postman (Gemini Image) node to your workflow (found under google/gemini)
3. Paste your API key into the api_key field

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 .pdf and .docx files 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