Gemini MCP Server

A Model Context Protocol (MCP) server that provides Google Gemini AI capabilities as tools. Built with Deno and TypeScript.

Features

• ask_gemini: Unified AI assistant powered by Gemini 3 Pro with built-in Google Search and URL analysis capabilities

Prerequisites

• Deno (v1.40+)
• Google Gemini API key (Get one here)

Installation

Option 1: Use JSR Package (Recommended)

The easiest way is to use the published JSR package directly in your Claude Desktop configuration:

# No installation needed! Use jsr:@cong/gemini-mcp directly in your Claude config

Option 2: From Source

1. Clone this repository:

git clone <repository-url>
cd gemini-mcp

2. Set your environment variables:

export GEMINI_API_KEY=your_api_key_here
export GEMINI_MODEL=gemini-3-pro-preview

Usage

Start the Server

# Set your environment variables first
export GEMINI_API_KEY=your_api_key_here
export GEMINI_MODEL=gemini-3-pro-preview

# Development mode (with watch)
deno task dev

# Production mode
deno task start

Testing with MCP Inspector

To test the server with the MCP Inspector, make sure your environment variables are set:

# Set environment variables in your shell
export GEMINI_API_KEY=your_api_key_here
export GEMINI_MODEL=gemini-3-pro-preview

# Install MCP Inspector if you haven't already
npm install -g @modelcontextprotocol/inspector

# Run the inspector
npx @modelcontextprotocol/inspector src/server.ts

Important: The environment variables must be set in the same shell where you run the MCP Inspector.

Run Tests

# Run all tests
deno task test

# Run tests with watch mode
deno task test:watch

Code Quality

# Format code
deno fmt

# Lint code
deno lint

MCP Tool

ask_gemini

The unified AI assistant powered by Gemini 3 Pro with built-in Google Search and URL analysis capabilities.

Parameters:

• prompt (required): Your question or request. Include URLs directly in the text for analysis.

Example:

{
  "name": "ask_gemini",
  "arguments": {
    "prompt": "What are the latest developments in quantum computing? Please analyze this paper: https://arxiv.org/abs/2301.01234"
  }
}

Capabilities:

• 🔍 Automatically searches the web for current information
• 📄 Analyzes URLs mentioned in your prompt text
• 🧠 Uses Gemini 3 Pro with thinking capabilities, urlContext and googleSearch tools
• 📚 Provides comprehensive, well-sourced answers with enhanced reasoning

Dependencies

• @modelcontextprotocol/sdk - MCP TypeScript SDK
• @google/generative-ai - Google Gemini API client
• zod - Runtime type validation
• @std/assert - Deno standard library assertions

Development

This project uses Deno with TypeScript. Key development commands:

• deno task dev - Start development server with watch mode
• deno task test - Run test suite
• deno cache src/server.ts - Cache dependencies
• deno fmt - Format code
• deno lint - Lint code

Troubleshooting

Environment Variable Issues

If you get environment variable errors:

1. Verify your environment variables are set:

   echo $GEMINI_API_KEY
   echo $GEMINI_MODEL
   

2. For MCP Inspector testing, ensure both variables are set in the same terminal:

   export GEMINI_API_KEY=your_api_key_here
   export GEMINI_MODEL=gemini-3-pro-preview
   npx @modelcontextprotocol/inspector src/server.ts
   

3. Check the server logs: When the server starts, it will show (API Key: configured) to confirm your key is loaded.

Support

• Google Gemini API Documentation
• Model Context Protocol
• Deno Documentation

Claude Desktop Configuration

To use this MCP server with Claude Desktop, add it to your Claude configuration:

macOS/Linux/Windows

Edit your Claude configuration file:

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

{
  "mcpServers": {
    "gemini": {
      "command": "deno",
      "args": [
        "run",
        "--allow-net",
        "--allow-env",
        "jsr:@cong/gemini-mcp"
      ],
      "env": {
        "GEMINI_API_KEY": "your_api_key_here",
        "GEMINI_MODEL": "gemini-3-pro-preview"
      }
    }
  }
}

Local Development

If you're running from source code:

{
  "mcpServers": {
    "gemini": {
      "command": "deno",
      "args": [
        "run",
        "--allow-net",
        "--allow-env",
        "src/server.ts"
      ],
      "env": {
        "GEMINI_API_KEY": "your_api_key_here",
        "GEMINI_MODEL": "gemini-3-pro-preview"
      }
    }
  }
}

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run tests: deno task test
5. Format code: deno fmt
6. Submit a pull request

License

MIT License - see LICENSE file for details.