Context Manager MCP Server

import { Transform } from 'stream'; /** * Handles framing of JSON-RPC messages using Content-Length headers * Format: * Content-Length: <length>\r\n * \r\n * <message> */ export class MessageFramer extends Transform { private buffer: Buffer; private contentLength: number | null; constructor() { super({ readableObjectMode: true, writableObjectMode: false }); this.buffer = Buffer.alloc(0); this.contentLength = null; } _transform(chunk: Buffer, encoding: string, callback: Function): void { // Append new data to existing buffer this.buffer = Buffer.concat([this.buffer, chunk]); // Process complete messages while (this.processNextMessage()) { // Continue until no more complete messages } callback(); } private processNextMessage(): boolean { // Need to find header boundary first if (this.contentLength === null) { const headerEnd = this.buffer.indexOf('\r\n\r\n'); if (headerEnd === -1) { return false; // Not enough data for headers } // Parse Content-Length header const header = this.buffer.slice(0, headerEnd).toString(); const match = header.match(/Content-Length: (\d+)/); if (!match) { this.emit('error', new Error('Invalid message header')); return false; } this.contentLength = parseInt(match[1], 10); this.buffer = this.buffer.slice(headerEnd + 4); // Skip header + separator } // Check if we have a complete message if (this.buffer.length >= this.contentLength!) { try { // Parse and emit the message const message = JSON.parse(this.buffer.slice(0, this.contentLength!).toString()); this.push(message); // Remove processed message from buffer this.buffer = this.buffer.slice(this.contentLength!); this.contentLength = null; return true; // Indicate we found a message } catch (err) { this.emit('error', new Error('Invalid JSON in message')); return false; } } return false; // Not enough data for message } /** * Frame a message with Content-Length header */ static frame(message: any): Buffer { const json = JSON.stringify(message); const header = `Content-Length: ${Buffer.byteLength(json)}\r\n\r\n`; return Buffer.from(header + json); } }