NCP - Natural Context Provider

/** * MCP Protocol Logger * * Two separate logs: * 1. Communication log (mcp-protocol.jsonl) - All MCP requests/responses including handshake * 2. Error log (mcp-errors.jsonl) - All errors that occur during MCP operations * * - Only active when NCP_DEBUG=true * - Rotation settings configurable via ~/.ncp/settings.json * - Auto-rotates by trimming top lines (default: 2000 lines = 1000 request/response pairs) */ import { promises as fs } from 'fs'; import { join } from 'path'; import { getNcpBaseDirectory } from './ncp-paths.js'; import { loadGlobalSettings } from './global-settings.js'; export class MCPProtocolLogger { private protocolLogPath: string; private errorLogPath: string; private enabled: boolean; private writeQueue: Promise<void> = Promise.resolve(); private rotationEnabled: boolean = true; private maxLines: number = 2000; private settingsLoaded: Promise<void>; constructor() { this.enabled = process.env.NCP_DEBUG === 'true'; if (this.enabled) { const ncpDir = getNcpBaseDirectory(); const logsDir = join(ncpDir, 'logs'); this.protocolLogPath = join(logsDir, 'mcp-protocol.jsonl'); this.errorLogPath = join(logsDir, 'mcp-errors.jsonl'); // Ensure logs directory exists (async) fs.mkdir(logsDir, { recursive: true }).catch(error => { // Silent fail - don't break initialization console.error(`[MCP Protocol Logger] Failed to create logs directory: ${error}`); }); // Load settings asynchronously this.settingsLoaded = this.loadSettings(); } else { this.protocolLogPath = ''; this.errorLogPath = ''; this.settingsLoaded = Promise.resolve(); } } /** * Load rotation settings from global config */ private async loadSettings(): Promise<void> { try { const settings = await loadGlobalSettings(); this.rotationEnabled = settings.logRotation.enabled; this.maxLines = settings.logRotation.maxProtocolLines; } catch (error) { // Use defaults if loading fails console.error(`[MCP Protocol Logger] Failed to load settings, using defaults: ${error}`); } } /** * Log MCP initialize handshake (request + response) */ async logInitialize(clientInfo: any, serverInfo: any, protocolVersion: string): Promise<void> { if (!this.enabled) return; // Log initialize request const requestEntry = { type: 'request', timestamp: new Date().toISOString(), method: 'initialize', params: { protocolVersion, clientInfo, capabilities: {} } }; await this.appendLine(this.protocolLogPath, JSON.stringify(requestEntry)); // Log initialize response const responseEntry = { type: 'response', timestamp: new Date().toISOString(), method: 'initialize', result: { protocolVersion, serverInfo, capabilities: { tools: {}, prompts: {}, resources: {}, elicitation: {} } } }; await this.appendLine(this.protocolLogPath, JSON.stringify(responseEntry)); } /** * Log an MCP request */ async logRequest(method: string, params: any): Promise<void> { if (!this.enabled) return; const entry = { type: 'request', timestamp: new Date().toISOString(), method, params }; await this.appendLine(this.protocolLogPath, JSON.stringify(entry)); } /** * Log an MCP response */ async logResponse(method: string, result: any, error?: any): Promise<void> { if (!this.enabled) return; const entry = { type: 'response', timestamp: new Date().toISOString(), method, ...(error ? { error } : { result }) }; await this.appendLine(this.protocolLogPath, JSON.stringify(entry)); } /** * Log an error to the error log */ async logError(error: any, context?: string): Promise<void> { if (!this.enabled) return; const entry = { timestamp: new Date().toISOString(), context: context || 'unknown', error: { message: error.message || String(error), stack: error.stack, code: error.code, ...error } }; await this.appendLine(this.errorLogPath, JSON.stringify(entry)); } /** * Append a line to the specified log file with rotation */ private async appendLine(logPath: string, line: string): Promise<void> { // Ensure settings are loaded first await this.settingsLoaded; // Queue writes to avoid race conditions this.writeQueue = this.writeQueue.then(async () => { try { // Read current content if file exists let lines: string[] = []; try { const content = await fs.readFile(logPath, 'utf-8'); lines = content.split('\n').filter(l => l.trim().length > 0); } catch (err: any) { // File doesn't exist yet - that's ok, lines array is empty if (err.code !== 'ENOENT') throw err; } // Add new line lines.push(line); // Rotate if enabled and needed (keep last maxLines) if (this.rotationEnabled && lines.length > this.maxLines) { lines = lines.slice(-this.maxLines); } // Write back await fs.writeFile(logPath, lines.join('\n') + '\n', 'utf-8'); } catch (error: any) { // Silent fail - don't break MCP operations due to logging issues console.error(`[MCP Protocol Logger] Failed to write: ${error.message}`); } }); return this.writeQueue; } /** * Clear the protocol log */ async clear(): Promise<void> { if (!this.enabled) return; try { // Try to delete both files - ignore ENOENT if they don't exist await fs.unlink(this.protocolLogPath).catch(err => { if (err.code !== 'ENOENT') throw err; }); await fs.unlink(this.errorLogPath).catch(err => { if (err.code !== 'ENOENT') throw err; }); } catch (error: any) { console.error(`[MCP Protocol Logger] Failed to clear: ${error.message}`); } } /** * Read recent protocol logs * @param count Number of request/response pairs to return (default: 100) */ async readRecent(count: number = 100): Promise<string> { if (!this.enabled) return ''; try { const content = await fs.readFile(this.protocolLogPath, 'utf-8'); const lines = content.split('\n').filter(l => l.trim().length > 0); // Get last N*2 lines (each pair = request + response) const recentLines = lines.slice(-(count * 2)); return recentLines.join('\n'); } catch (error: any) { return `Error reading protocol log: ${error.message}` ; } } } // Singleton instance export const mcpProtocolLogger = new MCPProtocolLogger();