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YCSE/nanobanana-mcp

Gemini Vision & Image Generation MCP for Claude Desktop and Claude Code

NanoBanana MCP

npm
MCP
Gemini
License

MCP server that brings Gemini's image generation and editing capabilities to Claude Desktop, Claude Code, and Cursor. Supports Nano Banana 2 (Flash) and Nano Banana Pro models.

Features

  • Image Generation - Create 2K images from text prompts
  • Image Editing - Transform images with natural language instructions
  • Session Consistency - Maintain style/character across generations
  • Runtime Model Switching - Switch between Flash and Pro models without restart
  • Multi-turn Chat - Conversational context with image support

Quick Start

Prerequisites

Add to Claude Code

claude mcp add nanobanana-mcp -- npx -y @ycse/nanobanana-mcp \
  -e "GOOGLE_AI_API_KEY=your_api_key"

Add to Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "nanobanana-mcp": {
      "command": "npx",
      "args": ["-y", "@ycse/nanobanana-mcp"],
      "env": {
        "GOOGLE_AI_API_KEY": "your_api_key"
      }
    }
  }
}

Add to Cursor

Create or edit .cursor/mcp.json (project-level) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "nanobanana-mcp": {
      "command": "npx",
      "args": ["-y", "@ycse/nanobanana-mcp"],
      "env": {
        "GOOGLE_AI_API_KEY": "your_api_key"
      }
    }
  }
}

See Cursor MCP Documentation for more details.

Tools

Tool Purpose
set_aspect_ratio Required. Set aspect ratio before image generation
set_model Switch between flash/pro models at runtime
gemini_generate_image Generate images from text prompts
gemini_edit_image Edit images with natural language
gemini_chat Multi-turn conversation with images
get_image_history View session image history
clear_conversation Reset session context

set_aspect_ratio (Required)

Must be called before generating or editing images.

Valid ratios: 1:1, 9:16, 16:9, 3:4, 4:3, 3:2, 2:3, 5:4, 4:5, 21:9

set_model

Switch models per-session without restarting:

Value Model Description
flash gemini-3.1-flash-image-preview Nano Banana 2 - Faster (default)
pro gemini-3-pro-image-preview Nano Banana Pro - Higher quality

gemini_generate_image

{
  prompt: string;              // Image description
  aspect_ratio?: string;       // Override session ratio
  output_path?: string;        // Save path (default: ~/Documents/nanobanana_generated/)
  conversation_id?: string;    // Session ID
  use_image_history?: boolean; // Use previous images for consistency
  reference_images?: string[]; // Reference images for style
}

gemini_edit_image

{
  image_path: string;          // File path, "last", or "history:N"
  edit_prompt: string;         // Edit instructions
  aspect_ratio?: string;       // Override session ratio
  output_path?: string;        // Save path
  conversation_id?: string;    // Session ID
  reference_images?: string[]; // Style references
}

Slash Commands

Claude Code

npx @ycse/nanobanana-mcp --install-commands claude-code
# Or manually:
# mkdir -p ~/.claude/commands
# cp commands/claude-code/*.md ~/.claude/commands/

Cursor

npx @ycse/nanobanana-mcp --install-commands cursor
# Or manually:
# mkdir -p .cursor/commands
# cp commands/cursor/*.md .cursor/commands/

See Cursor Slash Commands for more details.

Available Commands

/nb-flash  - Switch to Flash model (faster)
/nb-pro    - Switch to Pro model (higher quality)

Usage Examples

Basic Generation

1. Set aspect ratio: set_aspect_ratio("16:9")
2. Generate: "A cyberpunk cityscape at sunset"

Character Consistency

// First image
{ prompt: "A red-hat cat", conversation_id: "cat" }

// Second image - same character
{ prompt: "The cat taking a nap", conversation_id: "cat", use_image_history: true }

Edit with History Reference

// Edit the last generated image
{ image_path: "last", edit_prompt: "Change hat to blue" }

// Edit specific image from history
{ image_path: "history:0", edit_prompt: "Add sunglasses" }

Switch Models Mid-Session

// Start with Flash for quick iterations
set_model({ model: "flash" })
{ prompt: "Draft concept art" }

// Switch to Pro for final render
set_model({ model: "pro" })
{ prompt: "Final polished version", use_image_history: true }

Configuration

Environment Variables

Variable Required Description
GOOGLE_AI_API_KEY Yes Google AI API key
NANOBANANA_MODEL No Default model (gemini-3.1-flash-image-preview or gemini-3-pro-image-preview)

Output Location

Generated images save to ~/Documents/nanobanana_generated/:

  • Generated: generated_[timestamp].png
  • Edited: [original]_edited_[timestamp].png

Development

git clone https://github.com/YCSE/nanobanana-mcp.git
cd nanobanana-mcp
npm install
npm run dev      # Development mode with hot reload
npm run build    # Production build
npm run start    # Run compiled server

Troubleshooting

Image generation fails:

  • Verify API key is valid
  • Check quota at Google AI Studio
  • Ensure set_aspect_ratio was called first

Tools not showing:

  1. Restart Claude Desktop/Code
  2. Check config file syntax
  3. Verify npx -y @ycse/nanobanana-mcp runs without errors

License

MIT

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