import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
/**
* Server Lifecycle
*
* Server lifecycle management functions for starting, connecting, and stopping the MCP server
*/
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { normalizeError } from "../errors";
import { logger } from "../logging";
import { serverConfig } from "./server.config";
import { setupErrorHandlers, setupSignalHandlers } from "./server.handlers";
import type { ServerCleanup } from "./server.handlers";
/**
* Server context containing MCP server instance and related components
*/
export interface ServerContext {
server: McpServer;
transport: StdioServerTransport;
cleanup: ServerCleanup;
}
/**
* Creates an MCP server and transport with associated cleanup function
*/
export async function createServer(): Promise<ServerContext> {
const server = new McpServer(serverConfig);
const transport = new StdioServerTransport();
let isCleaningUp = false;
// Create cleanup function
const cleanup: ServerCleanup = (exitCode = 0) => {
// Prevent multiple cleanup calls
if (isCleaningUp) {
logger.debug("Cleanup already in progress, ignoring duplicate call", {
prefix: "Server",
});
return;
}
isCleaningUp = true;
logger.info(`Shutting down MCP server (exit code: ${exitCode})...`, {
prefix: "Server",
});
try {
// Close transport first
if (transport) {
logger.debug("Closing transport...", { prefix: "Server" });
transport.close();
logger.debug("Transport closed successfully", { prefix: "Server" });
}
// Then close server
if (server) {
logger.debug("Closing server...", { prefix: "Server" });
server.close();
logger.debug("Server closed successfully", { prefix: "Server" });
}
// Give a small delay to allow for resource cleanup
setTimeout(() => {
logger.info("Cleanup completed, exiting process", { prefix: "Server" });
process.exit(exitCode);
}, 500);
} catch (error) {
logger.error(normalizeError(error), {
prefix: "Server",
});
process.exit(exitCode);
}
};
return { server, transport, cleanup };
}
/**
* Initializes the MCP server with all required setup and features
*
* @param registerFeaturesFn - Function to register features with the server
*/
export async function initializeServer(
registerFeaturesFn: (server: McpServer) => Promise<void>,
): Promise<void> {
logger.info("Starting MCP server initialization...", { prefix: "Server" });
// Create server and transport
const context = await createServer();
const { server, transport, cleanup } = context;
// Log server configuration
if (process.env.NODE_ENV === "development") {
logger.debug(
{
...serverConfig,
NODE_ENV: process.env.NODE_ENV || "development",
},
{ prefix: "Server Config" },
);
}
// Set up event handlers
setupErrorHandlers(cleanup);
setupSignalHandlers(cleanup);
// Register features
await registerFeaturesFn(server);
// Set up transport event handlers
transport.onclose = () => {
logger.info("Transport closed", { prefix: "Server" });
cleanup(0);
};
transport.onerror = (error: Error) => {
logger.error(error, { prefix: "Server" });
cleanup(1);
};
// Connect server with transport
await server.connect(transport);
logger.info("MCP Server connected successfully", { prefix: "Server" });
// Keep the process running
process.stdin.resume();
}
