Gemini RAG MCP Server

/** * MCP server implementation with stdio and http transport support */ import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { StreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/streamableHttp.js"; import express from "express"; import type { ServerConfig, TransportConfig } from "../types/index.js"; import { ToolRegistry } from "./tool-registry.js"; import { GeminiClient } from "../clients/gemini-client.js"; import type { ToolContext } from "../tools/base-tool.js"; /** * MCP server implementation */ export class MCPServerImpl { private server: McpServer; private config: ServerConfig | null = null; private toolRegistry: ToolRegistry | null = null; constructor() { this.server = new McpServer({ name: "mcp-server", version: "1.0.0", }); } /** * Initialize the MCP server with configuration */ initialize(config: ServerConfig): void { this.config = config; // Create Gemini client const geminiClient = new GeminiClient(config.gemini.apiKey); // Create tool context const toolContext: ToolContext = { geminiClient, storeDisplayName: config.gemini.storeDisplayName, defaultModel: config.gemini.model, }; // Setup tool registry and handlers this.toolRegistry = new ToolRegistry(this.server); // Initialize tool registry (loads tools automatically) this.toolRegistry.initialize(toolContext); this.toolRegistry.setupToolHandlers(); } /** * Start the server with specified transport */ async start(transport: TransportConfig): Promise<void> { if (!this.config) { throw new Error("Server not initialized. Call initialize() first."); } if (transport.type === "stdio") { const stdioTransport = new StdioServerTransport(); await this.server.connect(stdioTransport); // Don't log to stdout for stdio transport as it interferes with MCP protocol } else { const port = transport.port ?? 3000; const app = express(); app.use(express.json()); console.log("🌐 Setting up HTTP transport..."); // Health check endpoint app.get("/health", (_req, res) => { console.log("📊 Health check requested"); res.json({ status: "ok", timestamp: new Date().toISOString() }); }); // MCP Streamable HTTP endpoint app.post("/mcp", async (req, res) => { const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined, enableJsonResponse: true, }); res.on("close", () => { void transport.close(); }); await this.server.connect(transport); await transport.handleRequest(req, res, req.body); }); app.listen(port, () => { console.log("🚀 HTTP MCP Server started successfully!"); console.log(`🌐 Server listening on port ${String(port)}`); console.log(`📋 Available endpoints:`); console.log(` - GET /health - Health check endpoint`); console.log(` - POST /mcp - MCP Streamable HTTP endpoint`); if (this.toolRegistry) { console.log(`🔧 MCP Tools available: ${this.toolRegistry.getRegisteredTools().join(", ")}`); } }); // Keep the process alive await new Promise<void>(() => { // Process will be kept alive by HTTP server }); } } /** * Stop the server gracefully */ async stop(): Promise<void> { // Server cleanup if needed } /** * Get server instance */ getServer(): McpServer { return this.server; } }