Agent Communication MCP Server

import { Transport } from '@modelcontextprotocol/sdk/shared/transport.js'; import { JSONRPCRequest, JSONRPCResponse, JSONRPCNotification, JSONRPCMessage } from '@modelcontextprotocol/sdk/types.js'; export class MemoryTransport implements Transport { private pendingRequests = new Map<number | string, (response: JSONRPCResponse) => void>(); private connected = false; private _isClosed = false; // Properties that the MCP SDK sets onmessage?: (message: JSONRPCMessage) => void; onclose?: () => void; onerror?: (error: Error) => void; async start(): Promise<void> { this.connected = true; this._isClosed = false; } async connect(): Promise<void> { this.connected = true; this._isClosed = false; } async close(): Promise<void> { if (this._isClosed) return; this.connected = false; this._isClosed = true; if (this.onclose) { this.onclose(); } } async send(message: JSONRPCMessage): Promise<void> { if (!this.connected) { throw new Error('Transport is not connected'); } // Debug: Log all messages if (process.env.DEBUG_TRANSPORT) { console.log('Transport.send:', JSON.stringify(message, null, 2)); } // The server sends responses through this method // We'll capture them for our tests if ('result' in message || 'error' in message) { const response = message as JSONRPCResponse; const resolver = this.pendingRequests.get(response.id!); if (resolver) { resolver(response); this.pendingRequests.delete(response.id!); } else if (process.env.DEBUG_TRANSPORT) { console.log('No resolver found for response id:', response.id); } } } // For testing: simulate sending a request to the server async simulateRequest(request: JSONRPCRequest): Promise<JSONRPCResponse> { if (!this.onmessage) { throw new Error('No message handler registered'); } return new Promise<JSONRPCResponse>((resolve, reject) => { // Store the resolver for this request this.pendingRequests.set(request.id!, resolve); // Set a timeout to avoid hanging tests const timeoutId = setTimeout(() => { if (this.pendingRequests.has(request.id!)) { this.pendingRequests.delete(request.id!); reject(new Error('Request timeout')); } }, 20000); // Match vitest timeout (20s) // Override the resolver to clear the timeout const originalResolve = resolve; this.pendingRequests.set(request.id!, (response) => { clearTimeout(timeoutId); originalResolve(response); }); // Send the request to the server this.onmessage(request); }); } }