OpenRouter Image Generator MCP Server

A Model Context Protocol (MCP) server that enables AI assistants to generate and edit images using OpenRouter's Nano Banana (Gemini 2.5 Flash Image) model.

✨ Features

• 🎨 Image Generation - Create images from text descriptions
• ✏️ Image Editing - Edit existing images with instructions
• 📁 Automatic File Saving - Smart filename generation and organization
• 🚀 Fast & Lightweight - Optimized for quick responses
• 🔧 Easy Setup - Install with a single command
• 🛡️ Type Safe - Built with TypeScript and strict validation

🚀 Quick Start

1. Install

# Global installation
npm install -g openrouter-image-gen-mcp

# Or use with npx (recommended)
npx openrouter-image-gen-mcp

2. Get OpenRouter API Key

Get your free API key at https://openrouter.ai/keys

3. Configure OpenCode

Add to your OpenCode configuration:

{
  "mcp": {
    "image-generator": {
      "type": "local",
      "enabled": true,
      "command": ["npx", "openrouter-image-gen-mcp"],
      "environment": {
        "OPENROUTER_API_KEY": "sk-or-v1-your-api-key-here"
      }
    }
  }
}

4. Start Generating Images!

User: Generate an image: beautiful sunset over ocean

✅ Image generated and saved
📁 File: /home/user/generated_beautiful_sunset_2025-10-26T21-45-30.png
📏 Size: 245.67 KB
🎨 Model: google/gemini-2.5-flash-image-preview

📖 Usage Examples

Basic Image Generation

# Simple prompt
Generate an image: cute cat sitting on a windowsill

# Custom output path
Generate a landscape image and save as ./renders/mountain.png

Image Editing

# Edit existing image
Edit sunset.png by adding flying birds

# Edit with custom output
Edit portrait.jpg with sunglasses and save as ./edited/cool_person.png

List Available Models

List available image generation models

🛠️ Available Tools

generate_image

Generate an image from text description.

Parameters:

• prompt (required): Text description of image to generate
• output_path (optional): Path to save the image file
• model (optional): Model to use for generation

Response:

{
  "success": true,
  "model": "google/gemini-2.5-flash-image-preview",
  "prompt": "beautiful sunset",
  "file_path": "/path/to/generated_image.png",
  "file_size_kb": 245.67
}

edit_image

Edit an existing image based on instructions.

Parameters:

• image_url (required): URL or data URI of image to edit
• edit_prompt (required): Instructions for editing the image
• output_path (optional): Path to save the edited image
• model (optional): Model to use for editing

list_available_models

List supported image generation models with details.

🔧 Configuration

Environment Variables

• OPENROUTER_API_KEY (required): Your OpenRouter API key
• IMAGE_OUTPUT_DIR (optional): Default output directory for images
• LOG_LEVEL (optional): Logging verbosity (info or debug)

Supported Models

🏗️ Development

Project Structure

src/
├── index.ts              # Main entry point
├── server.ts             # MCP server setup
├── tools/
│   ├── generate.ts       # generate_image handler
│   ├── edit.ts           # edit_image handler
│   └── models.ts         # list_models handler
├── services/
│   └── openrouter.ts     # OpenRouter API client
└── utils/
    ├── filename.ts       # Filename generation
    ├── logger.ts         # Logging utilities
    └── validation.ts     # Input validation

Building

# Build the project
npm run build

# Watch for changes
npm run dev

# Run tests
npm test

# Lint code
npm run lint

# Format code
npm run format

Testing with MCP Inspector

# Start the inspector
npm run inspect

# Test tool calls in the inspector interface

📝 Error Handling

The server provides detailed error messages for common issues:

{
  "error": "OpenRouter API key not configured. Please set OPENROUTER_API_KEY environment variable.",
  "help": "Get your free API key at: https://openrouter.ai/keys"
}

Common errors:

• Missing API key
• Network connectivity issues
• Invalid image formats
• Insufficient API credits
• File system permissions

🤝 Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Model Context Protocol - For the protocol specification
• OpenRouter - For providing the API gateway
• Gemini - For the image generation model

📞 Support

• 🐛 Issues: GitHub Issues

Made with ❤️ for the AI community