Gemini MCP Server

# MCP Server Implementation Summary ## Overview This document summarizes the complete implementation of the Model Context Protocol (MCP) server for Google Gemini. ## Key Implementation Details ### 1. Protocol Research After initial attempts using WebSocket and Content-Length headers (similar to LSP), research revealed that MCP uses: - **Newline-delimited JSON** for stdio transport - Standard JSON-RPC 2.0 format - No Content-Length headers required ### 2. Architecture The server is implemented as a stdio-based Node.js application: - Reads JSON-RPC messages from stdin (line by line) - Writes responses to stdout (newline-delimited) - Logs all debug information to stderr ### 3. Implemented Methods - `initialize` - Returns server capabilities - `tools/list` - Lists the `generate_text` tool - `tools/call` - Executes Gemini text generation - `resources/list` - Returns empty array (for future expansion) - `prompts/list` - Returns empty array (for future expansion) ### 4. Key Features - Uses the new `@google/genai` SDK (migrated from deprecated SDK) - Full TypeScript with ESM modules - Proper error handling and validation - Compatible with Claude Desktop via npx ## Testing Results The server successfully: 1. Connects to Claude Desktop 2. Responds to all protocol messages 3. Generates text using Gemini when requested 4. Handles errors gracefully ## Lessons Learned 1. **Research First**: The initial WebSocket implementation was completely wrong. Proper research of MCP documentation was crucial. 2. **Protocol Matters**: Using Content-Length headers (LSP-style) broke the communication. MCP uses simpler newline-delimited JSON. 3. **Notifications**: MCP notifications (like `notifications/initialized`) don't require responses. 4. **Debug Carefully**: All console output must go to stderr to avoid breaking the stdio protocol. ## Future Improvements - Add more Gemini models - Implement streaming responses - Add resource providers for context - Create custom prompts