Spotify Streamable MCP Server

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'; import { SetLevelRequestSchema } from '@modelcontextprotocol/sdk/types.js'; import { config } from '../config/env.js'; import { registerPrompts } from '../prompts/index.js'; import { registerResources } from '../resources/index.js'; import { registerTools } from '../tools/index.js'; import { logger } from '../utils/logger.js'; import { buildCapabilities } from './capabilities.js'; export interface ServerOptions { name: string; version: string; instructions?: string; /** * Called when initialization is complete (after client sends notifications/initialized). * Per review finding #3: This fires AFTER transport.onsessioninitialized. * * Guaranteed ordering: * 1. transport.onsessioninitialized(sid) - session ID assigned * 2. server.oninitialized() - client confirmed ready * * At this point, you can safely: * - Access client capabilities via server.server.getClientCapabilities() * - Send server→client requests (sampling, elicitation, roots) */ oninitialized?: () => void; } export function buildServer(options: ServerOptions): McpServer { const { name, version, instructions, oninitialized } = options; const server = new McpServer( { name, version }, { capabilities: buildCapabilities(), instructions: instructions ?? config.MCP_INSTRUCTIONS, }, ); // Set up logging logger.setServer(server); // Register oninitialized callback // Per review finding #3: This fires after onsessioninitialized // biome-ignore lint/suspicious/noExplicitAny: accessing private SDK property const lowLevel = (server as any).server; if (lowLevel && oninitialized) { lowLevel.oninitialized = () => { logger.info('mcp', { message: 'Client initialization complete (notifications/initialized received)', clientVersion: lowLevel.getClientVersion?.(), }); oninitialized(); }; } // Register handlers registerTools(server); registerPrompts(server); registerResources(server); // Register logging/setLevel handler (required when logging capability is advertised) server.server.setRequestHandler(SetLevelRequestSchema, async (request) => { const level = request.params.level; logger.info('mcp', { message: 'Log level changed', level }); return {}; }); return server; }