ExpressJS MCP

import type { Application } from "express"; import { InMemoryDispatcher } from "./inMemoryDispatcher"; import { McpServer } from "./mcpServer"; import { RouteIntrospector } from "./routeIntrospector"; import { SchemaResolver } from "./schemaResolver"; export type RouteInfo = { method: string; path: string; middlewares: ((...args: unknown[]) => unknown)[]; handler: (...args: unknown[]) => unknown; }; export type ExpressMCPOptions = { mountPath?: string; openapi?: Record<string, unknown>; schemaAnnotations?: Record<string, unknown>; include?: (route: RouteInfo) => boolean; exclude?: (route: RouteInfo) => boolean; auth?: { enabled?: boolean }; logging?: { info: (...a: unknown[]) => void; error: (...a: unknown[]) => void; }; }; export class ExpressMCP { private server: McpServer; private dispatcher: InMemoryDispatcher; private introspector: RouteIntrospector; private schemas: SchemaResolver; constructor( private app: Application, private options: ExpressMCPOptions = {}, ) { this.introspector = new RouteIntrospector(app); this.dispatcher = new InMemoryDispatcher(app); this.schemas = new SchemaResolver(options); this.server = new McpServer(this.dispatcher, this.schemas, options.logging); } async init() { const routes = this.introspector.listRoutes(this.options); await this.server.loadRoutes(routes); } mount(path = this.options.mountPath ?? "/mcp") { this.server.mount(this.app, path); } async startStandalone({ port = 7878 }: { port?: number } = {}) { await this.server.listen(port); } listTools() { return this.server.listTools(); } }