KOF Nano Banana MCP Server 🍌

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

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⚠️ 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

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