@creating-cat/gemini-image-mcp-server

日本語版はこちら (Read in Japanese)

Gemini Image MCP Server

This is an MCP (Model Context Protocol) server that uses Google's Gemini API to generate images and save them to a specified directory. In addition to text prompts, you can optionally provide input images to guide the image generation process. Generated images are automatically compressed to reduce file size.

---

Features

• Image generation from text prompts
• (Optional) Image generation using input reference images
• Automatic compression of generated images (JPEG, PNG)
• Unique file name assignment to prevent file name conflicts
• Operates as an MCP server, accepting tool calls via standard input/output

---

Prerequisites

• Node.js (v18 or higher recommended)
• Google Cloud Project with Gemini API enabled
• Gemini API Key

---

Setup

Example MCP server configuration for Roo Code

{
  "mcpServers": {
    "gemini-image-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@creating-cat/gemini-image-mcp-server"
      ],
      "env": {
        "GEMINI_API_KEY": "YOUR_GEMINI_API_KEY"
      },
      "disabled": false,
      "timeout": 300
    }
  }
}

• Replace YOUR_GEMINI_API_KEY with your actual Gemini API Key.

  • You can also use ${env:GEMINI_API_KEY} to retrieve the key from environment variables (Roo Code feature).

---

Tool: generate_image

This MCP server provides a tool named generate_image.

Input Parameters

Parameter Name	Description	Default Value
prompt	(string, required) Text prompt for image generation. If input images are provided, include instructions on how to incorporate them into the generated image. English is recommended.	None
output_directory	(string, optional) Directory path where the generated image will be saved.	output/images
file_name	(string, optional) Name of the saved image file (without extension).	generated_image
input_image_paths	(string[], optional) List of file paths for input reference images.	[] (empty array)
use_enhanced_prompt	(boolean, optional) Whether to use enhanced prompts to assist AI instructions.	true
target_image_max_size	(number, optional) Maximum size (in pixels) for the longer edge after resizing. The aspect ratio is preserved.	512
force_conversion_type	(string, optional) Optionally force conversion to a specific format ('jpeg', 'webp', 'png'). If not specified, the original format will be processed, defaulting to PNG for non-JPEG images.	None
skip_compression_and_resizing	(boolean, optional) Whether to skip compression and resizing of generated images. If true, force_conversion_type and target_image_max_size will be ignored.	false
jpeg_quality	(number, optional) JPEG quality (0-100). Lower values result in higher compression.	80
webp_quality	(number, optional) WebP quality (0-100). Lower values result in higher compression.	80
png_compression_level	(number, optional) PNG compression level (0-9). Higher values result in higher compression.	9
optipng_optimization_level	(number, optional) OptiPNG optimization level (0-7). Higher values result in higher compression.	2

Output

On success, the server returns the save path of the generated image and a message detailing the process, including the original and compressed file sizes. Example:

{
  "content": [
    {
      "type": "text",
      "text": "Image successfully generated and compressed at output/images/my_cat.jpg.\nOriginal size: 1024.12KB, Final size: 150.45KB"
    }
  ]
}

If an error occurs, an error message will be returned.

---

Notes

• The MIME type and aspect ratio of the generated images depend on the default settings of the Gemini API.
• Handle your API key with care.
• This server uses the model gemini-2.0-flash-preview-image-generation. Google may discontinue this model in the future.

---

License

MIT