Nano Banana MCP Server

Nano Banana is an MCP server that exposes Google Gemini Flash 2.5 Image Generation via a clean, focused interface. It is not a general multi‑model server — it is a thin wrapper around Gemini Flash 2.5 image generation only.

✨ What It Does

Generate, edit, and manipulate images using natural language via any MCP‑compatible client.

🚀 Compatible Tools

Works with any MCP‑compatible client. Below we document Gemini CLI (recommended) and a minimal generic MCP configuration.

Features

🎨 Image Generation (Powered by Gemini Flash 2.5)

• Text-to-Image Generation: Create images from text descriptions

• Image Editing: Modify existing images with text prompts

• Multi-Image Composition: Combine multiple images or transfer styles

• Batch Generation: Generate multiple variations at once

🛠️ Image Manipulation (Powered by Sharp)

• Combine Images: Stitch images into panoramas, grids, or strips

• Transform Images: Resize, crop, rotate, flip, and flop

• Adjust Images: Blur, sharpen, grayscale, tint, brightness, saturation

• Composite Images: Layer images with blend modes and positioning

• Batch Processing: Apply operations to entire directories

🔧 Developer Features

• Smart Path Handling: Automatically creates directories and handles file paths

• Image Validation: Verify generated images are valid and meet size requirements

• Comprehensive Error Handling: Clear feedback on API errors, quota issues, and failures

• MCP Protocol: Works with any MCP-compatible AI client

🚀 Quick Install (1 Minute!)

Option 1: Global Install (Recommended)

Option 2: NPX (No Install)

Set your API key once in your shell (required):

Gemini CLI configuration (~/.gemini/settings.json):

Generic MCP configuration (for other clients using stdio):

Option 3: From Source

The quickstart script will:

• ✅ Check Node.js version

• ✅ Install Gemini CLI if needed

• ✅ Build the project

• ✅ Configure your API key

• ✅ Set up Gemini CLI integration

• ✅ Verify everything works

Minimal Setup (from source)

1. Configure API key:

2. Build:

3. Configure Gemini CLI using the JSON shown above.

Get your API key from: https://aistudio.google.com/apikey

CLI Commands

The Nano Banana CLI provides powerful management tools:

Important: Use setup to configure with Gemini CLI. The init command only creates a .env file.

Usage

Once configured, use with your MCP client of choice. Simply describe what you want:

• "Generate a cyberpunk city at ./city.png"

• "Create 5 potion icons at ./items/potions.png"

• "Add a sunset to ./photo.jpg"

• "Combine these images into a panorama"

🌟 Why Nano Banana?

• 🎨 Full Gemini Flash 2.5 Power: Access the latest image generation capabilities

• 🚀 Natural Language Interface: Just describe what you want

• 🔧 Flexible Integration: Works with Gemini CLI and other MCP clients

• 📁 Direct File Management: Images save exactly where you need them

• 🎯 Smart Context: One tool handles generation, editing, and composition

• ⚡ Batch Operations: Generate up to 10 variations at once

📚 Documentation

This README contains the supported setup paths. Nano Banana targets the Gemini Flash 2.5 image generation model only.

Available Tools

generate_image

Generate, edit, or compose images using Gemini Flash 2.5.

Parameters:

• prompt (optional): Text description for generation

• images (optional): Array of input images (base64 or file paths)

• outputPath: Where to save the generated image(s)

• count (optional): Number of variations to generate (1-10)

• options (optional): Additional Gemini model options

Examples:

Text-to-image:

Image editing:

Batch generation:

validate_image

Check if an image file exists and is valid.

Parameters:

• path: File path to validate

Returns:

• exists: Whether the file exists

• valid: Whether it's a valid image

• dimensions: Image width and height

• format: Image format (png, jpeg, etc.)

• fileSize: File size in bytes

• error: Error message if validation failed

How It Works

1. Flexible Input: The server intelligently determines the operation mode:

   • Text only → Text-to-image generation

   • Text + 1 image → Image editing

   • Text + multiple images → Composition/style transfer

2. Path Management: Automatically creates directories and handles both absolute and relative paths

3. Batch Support: When count > 1, generates multiple variations with numbered suffixes

4. Validation: Uses Sharp to verify images are properly generated and meet minimum size requirements

5. No Overwrites: The server never overwrites existing files. If the requested outputPath (or any batch variation path) already exists, the server returns an error and does not write. Choose a new path or remove the file before retrying.

Error Handling

The server provides detailed error information:

• INVALID_API_KEY: Authentication failed

• QUOTA_EXCEEDED: API limits reached

• API_ERROR: General API failure

• INVALID_INPUT: Bad parameters

• FILE_WRITE_ERROR: Cannot save to path

• VALIDATION_FAILED: Image corrupt or too small

• FILE_EXISTS: Output file already exists; choose a new path

Testing

Run the example test script:

This will test:

• Basic text-to-image generation

• Image validation

• Batch generation

Project Structure

🎮 Real-World Use Cases

Game Development

Web Development

Content Creation

🛠️ Requirements

• Node.js 18 or higher

• Gemini API Key with image generation access (Get one here)

• TypeScript 5.0+ (for development)

🔧 Project Status

This is an experimental sample project. While GitHub issues are welcome for bug reports and feedback, this project is not actively seeking contributions and long-term maintenance is not guaranteed at this time.

📄 License

MIT License - see LICENSE file for details

🙏 Acknowledgments

• Built with the Model Context Protocol

• Powered by Gemini Flash 2.5

• Inspired by the amazing MCP community

🔗 Links

• GitHub Repository

• Report Issues

• Gemini CLI

• Codex CLI

• MCP Specification