KOF Nano Banana Server

MCP server for Gemini native image generation (Nano Banana). Part of the KeepOnFirst Agentic Workflow.

English | 繁體中文

⚠️ Important: Billing Required

Note: The Gemini API Free Tier does NOT support image generation models. To use this MCP server, you must provide an API key from a Google Cloud project with billing enabled.

Features

• Generate images using Gemini 2.5 Flash Image or Gemini 3 Pro Image
• Process queue of prompt files with validation and dry-run support
• YAML frontmatter support for prompt configuration
• Cross-IDE compatible - works with any MCP-enabled client

☕ Support this project

If this project helps you, you can support development here:

Installation

Option 1: Use via npx (Recommended)

If you have published this package or use it locally:

{
  "mcpServers": {
    "nanobanana": {
      "command": "npx",
      "args": ["-y", "@keeponfirst/kof-nanobanana-mcp"],
      "env": {
        "GEMINI_API_KEY": "your-api-key-here"
      }
    }
  }
}

Option 2: Local Development

cd kof-nanobanana-mcp
npm install
npm run build

Then configure absolute path in your MCP config (see Configuration section).

Configuration

1. Get a Gemini API Key

1. Go to Google AI Studio
2. Create an API key
3. IMPORTANT: Ensure your project has billing enabled. These models are paid-only.

2. Add to MCP Config

Add to your MCP configuration file (e.g., ~/.gemini/antigravity/mcp_config.json):

{
  "servers": {
    "nanobanana": {
      "command": "node",
      "args": ["/path/to/kof-nanobanana-mcp/dist/index.js"],
      "env": {
        "GEMINI_API_KEY": "your-api-key-here"
      }
    }
  }
}

Tools

nanobanana_generate_image

Generate a single image.

Parameters:

Name	Type	Required	Description
prompt	string	✅	Image description (10-5000 chars)
output_path	string	✅	Path to save the image
model	string	❌	gemini-2.5-flash-image (default) or gemini-3-pro-image-preview
aspect_ratio	string	❌	1:1, 16:9, 9:16, 4:3, 3:4
overwrite	boolean	❌	Overwrite existing file (default: false)

Example:

{
  "prompt": "A modern flat illustration of three AI robots working together on code",
  "output_path": "assets/generated/workflow-hero.png",
  "model": "gemini-2.5-flash-image",
  "aspect_ratio": "16:9"
}

nanobanana_list_queue

List and validate prompt files in the queue.

Parameters:

Name	Type	Required	Description
queue_dir	string	❌	Queue directory (default: nanobanana/queue)
validate	boolean	❌	Validate files (default: true)
check_conflicts	boolean	❌	Check if outputs exist (default: true)

nanobanana_process_queue

Batch process all prompt files.

Parameters:

Name	Type	Required	Description
queue_dir	string	❌	Queue directory (default: nanobanana/queue)
validate_only	boolean	❌	Only validate, no generation
dry_run	boolean	❌	Preview without API calls
overwrite	string	❌	skip, overwrite, or rename

Prompt File Format

Create .md files in nanobanana/queue/ with YAML frontmatter:

---
output_path: assets/generated/workflow-hero.png
model: gemini-2.5-flash-image
aspect_ratio: 16:9
overwrite: false
---

# Workflow Hero Image

Create a modern, sleek hero illustration showing three AI agents
working together in a software development workflow.

## Style Guidelines
- Style: Flat illustration with gradients
- Color palette: Deep purple (#6B46C1) to blue (#3B82F6)
- Background: Subtle gradient

Pricing Reference

Model	Price per Image
Gemini 2.5 Flash Image	~$0.039 (1024x1024)
Gemini 3 Pro Image (2K)	~$0.134
Gemini 3 Pro Image (4K)	~$0.24

License

MIT