CLDGeminiPDF MCP Server

A Model Context Protocol (MCP) server that enables Claude Desktop to analyze PDF documents using Google's AI models. This server sends PDF files & extracts text from PDFs by leveraging Gemini's powerful language understanding to provide intelligent analysis and insights.

Quick Start

1. Download: Get the pre-built JAR from Releases

2. API Key: Get your free Gemini API key from Google AI Studio

3. Configure: Add the server to your Claude Desktop config with the JAR path and API key

4. Analyze: Start analyzing PDFs with Claude!

Features

• PDF Analysis: Extract and analyze PDF content using Gemini AI models
• Multiple Model Support: Choose from various Gemini models (2.5, 2.0, 1.5 series, and Gemma models)
• Dual Processing Methods: Direct PDF upload to Gemini or fallback text extraction
• MCP Integration: Seamless integration with Claude Desktop via Model Context Protocol
• Flexible Configuration: Environment-based configuration for easy deployment

Prerequisites

• Java 11 or higher
• Maven (for building from source)
• Google AI Studio API Key (free at aistudio.google.com)
• Claude Desktop application
• **Filesystem MCP Server** (required dependency)

Installation

Option 1: Download Pre-built JAR (Recommended)

1. Download the latest CLDGeminiPDF.v1.0.0.jar from the Releases page

2. Save it to a convenient location on your system

Option 2: Build from Source

git clone 
cd CLDGeminiPDF
mvn clean compile assembly:single

This will create a JAR file with all dependencies included in the target/ directory.

Get Your Gemini API Key

1. Visit Google AI Studio

2. Sign in with your Google account

3. Click "Get API Key" and create a new key

4. Copy the API key for use in environment variables

Claude Desktop Integration

1. Locate Claude Desktop Configuration

The configuration file location depends on your operating system:

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

2. Update Configuration File

Add both the filesystem server and CLDGeminiPDF server to your claude_desktop_config.json:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/path/to/your/documents"
      ]
    },
    "CLDGeminiPDF": {
      "command": "java",
      "args": [
        "-jar",
        "/path/to/CLDGeminiPDF.v1.0.0.jar"
      ],
      "env": {
        "GEMINI_API_KEY": "your_api_key_here",
        "GEMINI_MODEL": "gemini-2.0-flash"
      }
    }
  }
}

Important:

• Replace /path/to/your/documents with the directory containing your PDF files
• Replace /path/to/CLDGeminiPDF.v1.0.0.jar with the actual path to your downloaded JAR file
• Replace your_api_key_here with your actual Gemini API key

Example Paths:

• Windows: "C:\\Users\\YourName\\Downloads\\CLDGeminiPDF.v1.0.0.jar"
• macOS: "/Users/YourName/Downloads/CLDGeminiPDF.v1.0.0.jar"
• Linux: "/home/yourusername/Downloads/CLDGeminiPDF.v1.0.0.jar"

3. Restart Claude Desktop

Close and restart Claude Desktop for the changes to take effect.

Available Gemini Models

*Data for Free Tier Users of Google API*

*Model availability depends on your API key and usage tier. Check your Google AI Studio account for available models.*

*Data sourced from https://ai.google.dev/gemini-api/docs/rate-limits#free-tier*

Usage Examples

The CLDGeminiPDF MCP server requires the Filesystem MCP server to access PDF files. It works with complete file paths or by finding files within the allowed directory scope.

Note: Version 1.0.0 does NOT support drag-and-drop files in the chat interface. Files must be accessible through the filesystem server.

Once configured, you can use these commands in Claude Desktop:

Analyze a PDF with Full Path

Please analyze this research paper: file:///Users/username/Documents/research_paper.pdf

Focus on the methodology and conclusions.

Find and Analyze a PDF by Name

Find the "research_paper.pdf" file in the Documents directory and analyze it using Gemini.

List Available Models

What Gemini models are available for PDF analysis?

Use a Specific Model

Analyze this contract using the gemini-2.5-pro model: file:///path/to/contract.pdf

Look for key terms and potential risks.

Troubleshooting

Common Issues

1. "GEMINI_API_KEY environment variable is not set!"

• Ensure your API key is properly set in the Claude Desktop configuration
• Restart Claude Desktop after updating the configuration

2. "PDF file not found or not readable"

• Verify the file path is correct and within the filesystem server's allowed directory
• Ensure the PDF file exists and is readable
• Check file permissions

3. "Gemini API error: 401"

• Verify your API key is correct and valid
• Check if your API key has the necessary permissions in Google AI Studio

4. "Gemini API error: 429"

• You've hit rate limits. Wait and try again
• Consider using a model with higher rate limits (see table above)

5. Filesystem server not working

• Ensure the filesystem MCP server is properly configured
• Check that the directory path in the filesystem configuration is correct
• Verify Claude Desktop has permission to access the specified directory

Debugging

To enable detailed logging, you can modify the Java command in your configuration:

"args": [
  "-Djava.util.logging.level=INFO",
  "-jar",
  "/path/to/CLDGeminiPDF.v1.0.0.jar"
]

Verify Configuration

Test your setup by asking Claude Desktop:

List the available Gemini models

If successful, you should see a JSON response with available models and their capabilities.

Development

Building from Source

git clone 
cd CLDGeminiPDF
mvn clean compile assembly:single

The JAR file will be created in the target/ directory.

Dependencies

• Jackson (JSON processing)
• Apache PDFBox (PDF text extraction)
• MCP Java SDK (Model Context Protocol)
• Java HTTP Client (API communication)

Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

License

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

Support

For issues and questions:

• Check the troubleshooting section above
• Review Claude Desktop MCP documentation
• Check Google AI Studio API documentation
• Open an issue on this repository