Polybrain MCP Server

#!/usr/bin/env node import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { loadConfig } from "../config.js"; import { ConversationManager } from "../conversation-manager.js"; import { ServerLauncher } from "../launcher.js"; import { logger, setLogLevel } from "../logger.js"; import { registerTools } from "../mcp-tools.js"; import { OpenAIClient } from "../openai-client.js"; /** * Log only if debug mode is enabled via POLYBRAIN_DEBUG env var * This ensures launcher stdio stays pure for MCP protocol */ function debugLog( level: "debug" | "info" | "warn" | "error", message: string, context?: Record<string, unknown> | Error ): void { if (process.env.POLYBRAIN_DEBUG === "true") { if (context instanceof Error) { if (level === "error") { logger.error(message, context); } else { logger[level](message, { name: context.name, message: context.message, stack: context.stack, }); } } else { logger[level](message, context); } } } async function main(): Promise<void> { // Check for --restart flag if (process.argv[2] === "--restart") { try { if (process.env.POLYBRAIN_DEBUG !== "true") { setLogLevel("error"); } const config = loadConfig(); const launcher = new ServerLauncher(config.httpPort); await launcher.killServerByPort(); console.log("✓ Server restarted successfully"); process.exit(0); } catch (error) { const errorMessage = error instanceof Error ? error.message : String(error); console.error(`Error during restart: ${errorMessage}`); process.exit(1); } } try { // In stdio mode, suppress all logging by default to keep stdout pure for MCP protocol // Only enable logging if POLYBRAIN_DEBUG is explicitly set // Do this BEFORE loading config to suppress config logs if (process.env.POLYBRAIN_DEBUG !== "true") { setLogLevel("error"); // Suppress debug/info logs even if configured } const config = loadConfig(); if (process.env.POLYBRAIN_DEBUG === "true") { setLogLevel(config.logLevel); debugLog("debug", "Polybrain launcher started (debug mode)"); } // Ensure HTTP server is running const launcher = new ServerLauncher(config.httpPort); await launcher.ensureServerRunning(); debugLog("debug", "HTTP server is ready, starting MCP stdio mode"); // Initialize conversation manager const conversationManager = new ConversationManager(config.truncateLimit); // Initialize OpenAI clients for each model const openaiClients = new Map<string, OpenAIClient>(); for (const model of config.models) { openaiClients.set(model.id, new OpenAIClient(model.apiKey, model.baseUrl)); } // Create MCP server const mcpServer = new McpServer({ name: "polybrain", version: "1.0.0", }); // Register tools registerTools(mcpServer, conversationManager, openaiClients, config); // Connect via stdio const transport = new StdioServerTransport(); await mcpServer.connect(transport); debugLog("debug", "MCP server connected via stdio"); } catch (error) { const errorMessage = error instanceof Error ? error.message : String(error); // Check if this is a critical config error - always show these regardless of debug mode const isConfigError = errorMessage.includes("No configuration found") || errorMessage.includes("Failed to load config") || errorMessage.includes("Environment variable not found") || errorMessage.includes("Model must have"); if (isConfigError) { // Critical errors: always print to console.error, regardless of debug mode console.error(`Error: ${errorMessage}`); } else { // Non-critical errors: use debugLog debugLog( "error", "Failed to start MCP server", error instanceof Error ? error : new Error(errorMessage) ); } // Exit with error code - agent will handle the connection failure process.exit(1); } } main().catch((error) => { console.error("Fatal error:", error); process.exit(1); });