Nanobanana Mcp Server

Nano Banana MCP Server 🍌

A production-ready Model Context Protocol (MCP) server that provides AI-powered image generation capabilities through Google's Gemini models with intelligent model selection.

⭐ NEW: Nano Banana 2 — Gemini 3.1 Flash Image! 🍌🚀

Nano Banana 2 (gemini-3.1-flash-image-preview) is now the default model — delivering Pro-level quality at Flash speed:

• 🍌 Flash Speed + 4K Quality: Up to 3840px at Gemini 2.5 Flash latency
• 🌐 Google Search Grounding: Real-world knowledge for factually accurate images
• 🎯 Subject Consistency: Up to 5 characters and 14 objects per scene
• ✍️ Precision Text Rendering: Crystal-clear text placement in images
• 🏆 Gemini 3 Pro Image still available for maximum reasoning depth

✨ Features

• 🎨 Multi-Model AI Image Generation: Three Gemini models with intelligent automatic selection
• 🍌 Gemini 3.1 Flash Image (NB2): Default model — 4K resolution at Flash speed with grounding
• 🏆 Gemini 3 Pro Image: Maximum reasoning depth for the most complex compositions
• ⚡ Gemini 2.5 Flash Image: Legacy Flash model for high-volume rapid prototyping
• 🤖 Smart Model Selection: Automatically routes to NB2 or Pro based on your prompt
• 📐 Aspect Ratio Control ⭐ NEW: Specify output dimensions (1:1, 16:9, 9:16, 21:9, and more)
• 📋 Smart Templates: Pre-built prompt templates for photography, design, and editing
• 📁 File Management: Upload and manage files via Gemini Files API
• 🔍 Resource Discovery: Browse templates and file metadata through MCP resources
• 🛡️ Production Ready: Comprehensive error handling, logging, and validation
• ⚡ High Performance: Optimized architecture with intelligent caching

🚀 Quick Start

Prerequisites

1. Google Gemini API Key - Get one free here
2. Python 3.11+ (for development only)

Installation

Option 1: From MCP Registry (Recommended) This server is available in the Model Context Protocol Registry. Search for "nanobanana" or use the MCP name below with your MCP client.

mcp-name: io.github.zhongweili/nanobanana-mcp-server

Option 2: Using uvx

uvx nanobanana-mcp-server@latest

Option 3: Using pip

pip install nanobanana-mcp-server

🔧 Configuration

Authentication Methods

Nano Banana supports two authentication methods via NANOBANANA_AUTH_METHOD:

1. API Key (api_key): Uses GEMINI_API_KEY. Best for local development and simple deployments.
2. Vertex AI ADC (vertex_ai): Uses Google Cloud Application Default Credentials. Best for production on Google Cloud (Cloud Run, GKE, GCE).
3. Automatic (auto): Defaults to API Key if present, otherwise tries Vertex AI.

1. API Key Authentication (Default)

Set GEMINI_API_KEY environment variable.

2. Vertex AI Authentication (Google Cloud)

Required environment variables:

• NANOBANANA_AUTH_METHOD=vertex_ai (or auto)
• GCP_PROJECT_ID=your-project-id
• GCP_REGION=global (default; required for Gemini 3 Pro Image and NB2. Use us-central1 only for the legacy 2.5 Flash Image model.)

Prerequisites:

• Enable Vertex AI API: gcloud services enable aiplatform.googleapis.com
• Grant IAM Role: roles/aiplatform.user to the service account.

Claude Desktop

Option 1: Using Published Server (Recommended)

Add to your claude_desktop_config.json:

{  "mcpServers": {    "nanobanana": {      "command": "uvx",      "args": ["nanobanana-mcp-server@latest"],      "env": {        "GEMINI_API_KEY": "your-gemini-api-key-here"      }    }  }}

Option 2: Using Local Source (Development)

If you are running from source code, point to your local installation:

{  "mcpServers": {    "nanobanana-local": {      "command": "uv",      "args": ["run", "python", "-m", "nanobanana_mcp_server.server"],      "cwd": "/absolute/path/to/nanobanana-mcp-server",      "env": {        "GEMINI_API_KEY": "your-gemini-api-key-here"      }    }  }}

Option 3: Using Vertex AI (ADC)

To authenticate with Google Cloud Application Default Credentials (instead of an API Key):

{  "mcpServers": {    "nanobanana-adc": {      "command": "uvx",      "args": ["nanobanana-mcp-server@latest"],      "env": {        "NANOBANANA_AUTH_METHOD": "vertex_ai",        "GCP_PROJECT_ID": "your-project-id",        "GCP_REGION": "global"      }    }  }}

Configuration file locations:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Claude Code (VS Code Extension)

Install and configure in VS Code:

1. Install the Claude Code extension
2. Open Command Palette (Cmd/Ctrl + Shift + P)
3. Run "Claude Code: Add MCP Server"
4. Configure:
   json

   {  "name": "nanobanana",  "command": "uvx",  "args": ["nanobanana-mcp-server@latest"],  "env": {    "GEMINI_API_KEY": "your-gemini-api-key-here"  }}

Cursor

Add to Cursor's MCP configuration:

{  "mcpServers": {    "nanobanana": {      "command": "uvx",      "args": ["nanobanana-mcp-server@latest"],      "env": {        "GEMINI_API_KEY": "your-gemini-api-key-here"      }    }  }}

OpenAI Codex

Add to ~/.codex/config.toml (global) or .codex/config.toml (project-scoped):

[mcp_servers.nanobanana]command = "uvx"args = ["nanobanana-mcp-server@latest"]
[mcp_servers.nanobanana.env]GEMINI_API_KEY = "your-gemini-api-key-here"

Or add via the CLI:

codex mcp add

Codex supports both the CLI and VSCode extension using the same config.toml. Once added, Codex can call generate_image, edit_image, and upload_file tools directly in your coding sessions.

Note: The Codex config file is shared by the CLI and the IDE extension. A TOML syntax error will break both simultaneously, so validate your edits carefully.

Continue.dev (VS Code/JetBrains)

Add to your config.json:

{  "mcpServers": [    {      "name": "nanobanana",      "command": "uvx",      "args": ["nanobanana-mcp-server@latest"],      "env": {        "GEMINI_API_KEY": "your-gemini-api-key-here"      }    }  ]}

Open WebUI

Configure in Open WebUI settings:

{  "mcp_servers": {    "nanobanana": {      "command": ["uvx", "nanobanana-mcp-server@latest"],      "env": {        "GEMINI_API_KEY": "your-gemini-api-key-here"      }    }  }}

Gemini CLI / Generic MCP Client

# Set environment variableexport GEMINI_API_KEY="your-gemini-api-key-here"
# Run server in stdio modeuvx nanobanana-mcp-server@latest
# Or with pip installationpython -m nanobanana_mcp_server.server

🤖 Model Selection

Nano Banana supports three Gemini models with intelligent automatic selection:

🍌 NB2 — Nano Banana 2 (Gemini 3.1 Flash Image) ⭐ DEFAULT

Flash speed with Pro-level quality — the best of both worlds

• Quality: Production-ready 4K output
• Resolution: Up to 4K (3840px)
• Speed: ~2-4 seconds per image (Flash-class latency)
• Special Features:
  • 🌐 Google Search Grounding: Real-world knowledge for factually accurate images
  • 🎯 Subject Consistency: Up to 5 characters and 14 objects per scene
  • ✍️ Precision Text Rendering: Clear, well-placed text in images
• Best for: Almost everything — production assets, marketing, photography, text overlays
• model_tier: "nb2" (or "auto" — NB2 is the auto default)

🏆 Pro Model — Nano Banana Pro (Gemini 3 Pro Image)

Maximum reasoning depth for the most demanding compositions

• Quality: Highest available
• Resolution: Up to 4K (3840px)
• Speed: ~5-8 seconds per image
• Special Features:
  • 🧠 Advanced Reasoning: Configurable thinking levels (LOW/HIGH)
  • 🌐 Google Search Grounding: Real-world knowledge integration
  • 📐 Media Resolution Control: Fine-tune vision processing detail
• Best for: Complex narrative scenes, intricate compositions, maximum reasoning required
• model_tier: "pro"

⚡ Flash Model (Gemini 2.5 Flash Image)

Legacy model for high-volume rapid iteration

• Speed: Very fast (2-3 seconds)
• Resolution: Up to 1024px
• Best for: High-volume generation, quick drafts where 4K is not needed
• model_tier: "flash"

🤖 Automatic Selection (Recommended)

By default, the server uses AUTO mode which routes to NB2 unless Pro's deeper reasoning is clearly needed:

Pro Model Selected When:

• Strong quality keywords: "4K", "professional", "production", "high-res", "HD"
• High thinking level requested: thinking_level="HIGH"
• Multi-image conditioning with multiple input images

NB2 Model Selected When (default):

• Standard requests, everyday image generation
• Speed keywords: "quick", "draft", "sketch", "rapid"
• High-volume batch generation (n > 2)

Usage Examples

# Automatic selection (recommended) — routes to NB2 by default"A cat sitting on a windowsill"             # → NB2 (default)"Quick sketch of a cat"                     # → NB2 (speed keyword, NB2 is fast enough)"Professional 4K product photo"             # → Pro (strong quality keywords)
# Explicit NB2 selectiongenerate_image(    prompt="Product photo on white background",    model_tier="nb2",              # Nano Banana 2 (Flash speed + 4K)    resolution="4k",    enable_grounding=True)
# Leverage Nano Banana Pro for complex reasoninggenerate_image(    prompt="Cinematic scene: three characters in a tense standoff at dusk",    model_tier="pro",              # Pro for deep reasoning    resolution="4k",    thinking_level="HIGH",         # Enhanced reasoning    enable_grounding=True)
# Legacy Flash for high-volume draftsgenerate_image(    prompt="Simple icon",    model_tier="flash"             # Fast 1024px generation)
# Control aspect ratio for different formats ⭐ NEW!generate_image(    prompt="Cinematic landscape at sunset",    aspect_ratio="21:9"            # Ultra-wide cinematic format)
generate_image(    prompt="Instagram post about coffee",    aspect_ratio="1:1"             # Square format for social media)
generate_image(    prompt="YouTube thumbnail design",    aspect_ratio="16:9"            # Standard video format)
generate_image(    prompt="Mobile wallpaper of mountain vista",    aspect_ratio="9:16"            # Portrait format for phones)

📐 Aspect Ratio Control

Control the output image dimensions with the aspect_ratio parameter:

Supported Aspect Ratios:

• 1:1 - Square (Instagram, profile pictures)
• 4:3 - Classic photo format
• 3:4 - Portrait orientation
• 16:9 - Widescreen (YouTube thumbnails, presentations)
• 9:16 - Mobile portrait (phone wallpapers, stories)
• 21:9 - Ultra-wide cinematic
• 2:3, 3:2, 4:5, 5:4 - Various photo formats

# Examples for different use casesgenerate_image(    prompt="Product showcase for e-commerce",    aspect_ratio="3:4",    # Portrait format, good for product pages    model_tier="pro")
generate_image(    prompt="Social media banner for Facebook",    aspect_ratio="16:9"    # Landscape banner format)

Note: Aspect ratio works with both Flash and Pro models. For best results with specific aspect ratios at high resolution, use the Pro model with resolution="4k".

📁 Output Path Control ⭐ NEW!

Control where generated images are saved with the output_path parameter:

Three modes of operation:

1. Specific file path - Save to an exact file location:

generate_image(    prompt="A beautiful sunset",    output_path="/path/to/sunset.png"  # Exact file location)

2. Directory path - Use auto-generated filename in a specific directory:

generate_image(    prompt="Product photo",    output_path="/path/to/products/"  # Trailing slash indicates directory)

3. Default location - Uses IMAGE_OUTPUT_DIR or ~/nanobanana-images:

generate_image(    prompt="Random image"    # output_path defaults to None)

Multiple images (n > 1): When generating multiple images with a file path, images are automatically numbered:

• First image: /path/to/image.png
• Second image: /path/to/image_2.png
• Third image: /path/to/image_3.png

Precedence Rules:

1. output_path parameter (if provided) - highest priority
2. IMAGE_OUTPUT_DIR environment variable
3. ~/nanobanana-images (default fallback)

IMAGE_OUTPUT_DIR is used only when output_path is omitted. A relative output_path such as images/sunset.png is resolved from the server process working directory, not from IMAGE_OUTPUT_DIR. ~/... expands to the home directory. A trailing slash selects directory mode even when that directory does not exist yet (outputs/), and the server creates it and generates the filename.

# Save to specific location with Pro modelgenerate_image(    prompt="Professional headshot",    model_tier="pro",    output_path="/Users/me/photos/headshot.png")
# Save multiple images to a directorygenerate_image(    prompt="Product variations",    n=4,    output_path="/path/to/products/"  # Each gets unique filename)

⚙️ Environment Variables

Configuration options:

# Authentication (Required)# Method 1: API KeyGEMINI_API_KEY=your-gemini-api-key-here
# Method 2: Vertex AI (Google Cloud)NANOBANANA_AUTH_METHOD=vertex_aiGCP_PROJECT_ID=your-project-idGCP_REGION=global  # Required for gemini-3-pro-image-preview and NB2; use "us-central1" only for legacy 2.5 Flash Image
# Model Selection (optional)NANOBANANA_MODEL=auto  # Options: flash, nb2, pro, auto (default: auto → nb2)
# OptionalIMAGE_OUTPUT_DIR=/path/to/image/directory  # Default: ~/nanobanana-imagesGEMINI_BASE_URL=https://custom-api.example.com  # Custom API endpoint (for proxies/gateways)LOG_LEVEL=INFO                             # DEBUG, INFO, WARNING, ERRORLOG_FORMAT=standard                        # standard, json, detailed

🐛 Troubleshooting

Common Issues

"GEMINI_API_KEY not set"

• Add your API key to the MCP server configuration in your client
• Get a free API key at Google AI Studio

"Server failed to start"

• Ensure you're using the latest version: uvx nanobanana-mcp-server@latest
• Check that your client supports MCP (Claude Desktop 0.10.0+)

"Permission denied" errors

• The server creates images in ~/nanobanana-images by default
• Ensure write permissions to your home directory

Development Setup

For local development:

# Clone repositorygit clone https://github.com/zhongweili/nanobanana-mcp-server.gitcd nanobanana-mcp-server
# Install with uvuv sync
# Set environmentexport GEMINI_API_KEY=your-api-key-here
# Run locallyuv run python -m nanobanana_mcp_server.server

📄 License

MIT License - see LICENSE for details.

🆘 Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions