Unreal Engine MCP Server

import http from 'http'; import { HealthMonitor } from './health-monitor.js'; import { AutomationBridge } from '../automation/index.js'; import { Logger } from '../utils/logger.js'; import { wasmIntegration } from '../wasm/index.js'; interface MetricsServerOptions { healthMonitor: HealthMonitor; automationBridge: AutomationBridge; logger: Logger; } function formatPrometheusMetrics(options: MetricsServerOptions): string { const { healthMonitor, automationBridge } = options; const m = healthMonitor.metrics; const status = automationBridge.getStatus(); const wasmMetrics = wasmIntegration.getMetrics(); const wasmStatus = wasmIntegration.getStatus(); const lines: string[] = []; // Basic request counters lines.push('# HELP unreal_mcp_requests_total Total number of tool requests seen by the MCP server.'); lines.push('# TYPE unreal_mcp_requests_total counter'); lines.push(`unreal_mcp_requests_total ${m.totalRequests}`); lines.push('# HELP unreal_mcp_requests_success_total Total number of successful tool requests.'); lines.push('# TYPE unreal_mcp_requests_success_total counter'); lines.push(`unreal_mcp_requests_success_total ${m.successfulRequests}`); lines.push('# HELP unreal_mcp_requests_failed_total Total number of failed tool requests.'); lines.push('# TYPE unreal_mcp_requests_failed_total counter'); lines.push(`unreal_mcp_requests_failed_total ${m.failedRequests}`); // Response time summary (simple gauges) lines.push('# HELP unreal_mcp_average_response_time_ms Average response time of recent tool requests (ms).'); lines.push('# TYPE unreal_mcp_average_response_time_ms gauge'); lines.push(`unreal_mcp_average_response_time_ms ${Number.isFinite(m.averageResponseTime) ? m.averageResponseTime.toFixed(2) : '0'}`); // Connection status gauges lines.push('# HELP unreal_mcp_unreal_connected Whether the Unreal automation bridge is currently connected (1) or not (0).'); lines.push('# TYPE unreal_mcp_unreal_connected gauge'); lines.push(`unreal_mcp_unreal_connected ${status.connected ? 1 : 0}`); lines.push('# HELP unreal_mcp_automation_pending_requests Number of pending automation bridge requests.'); lines.push('# TYPE unreal_mcp_automation_pending_requests gauge'); lines.push(`unreal_mcp_automation_pending_requests ${status.pendingRequests}`); lines.push('# HELP unreal_mcp_automation_max_pending_requests Configured maximum number of pending automation bridge requests.'); lines.push('# TYPE unreal_mcp_automation_max_pending_requests gauge'); lines.push(`unreal_mcp_automation_max_pending_requests ${status.maxPendingRequests}`); lines.push('# HELP unreal_mcp_automation_max_concurrent_connections Configured maximum concurrent automation bridge connections.'); lines.push('# TYPE unreal_mcp_automation_max_concurrent_connections gauge'); lines.push(`unreal_mcp_automation_max_concurrent_connections ${status.maxConcurrentConnections}`); // WASM integration metrics lines.push('# HELP unreal_mcp_wasm_enabled Whether the optional WebAssembly integration is enabled (1) or not (0).'); lines.push('# TYPE unreal_mcp_wasm_enabled gauge'); lines.push(`unreal_mcp_wasm_enabled ${wasmStatus.enabled ? 1 : 0}`); lines.push('# HELP unreal_mcp_wasm_ready Whether the WebAssembly module has been initialized successfully (1) or not (0).'); lines.push('# TYPE unreal_mcp_wasm_ready gauge'); lines.push(`unreal_mcp_wasm_ready ${wasmStatus.ready ? 1 : 0}`); lines.push('# HELP unreal_mcp_wasm_operations_total Total number of WASM-related operations recorded by the integration layer.'); lines.push('# TYPE unreal_mcp_wasm_operations_total counter'); lines.push(`unreal_mcp_wasm_operations_total ${wasmMetrics.totalOperations}`); lines.push('# HELP unreal_mcp_wasm_operations_wasm_total Number of operations that used the WebAssembly implementation.'); lines.push('# TYPE unreal_mcp_wasm_operations_wasm_total counter'); lines.push(`unreal_mcp_wasm_operations_wasm_total ${wasmMetrics.wasmOperations}`); lines.push('# HELP unreal_mcp_wasm_operations_ts_total Number of operations that used the TypeScript fallback implementation.'); lines.push('# TYPE unreal_mcp_wasm_operations_ts_total counter'); lines.push(`unreal_mcp_wasm_operations_ts_total ${wasmMetrics.tsOperations}`); // Uptime in seconds const uptimeSeconds = Math.floor((Date.now() - m.uptime) / 1000); lines.push('# HELP unreal_mcp_uptime_seconds MCP server uptime in seconds (since HealthMonitor was created).'); lines.push('# TYPE unreal_mcp_uptime_seconds gauge'); lines.push(`unreal_mcp_uptime_seconds ${uptimeSeconds}`); return lines.join('\n') + '\n'; } export function startMetricsServer(options: MetricsServerOptions): http.Server | null { const { logger } = options; const portEnv = process.env.MCP_METRICS_PORT || process.env.PROMETHEUS_PORT; const port = portEnv ? Number(portEnv) : 0; if (!port || !Number.isFinite(port) || port <= 0) { logger.debug('Metrics server disabled (set MCP_METRICS_PORT to enable Prometheus /metrics endpoint).'); return null; } const host = process.env.MCP_METRICS_HOST || '127.0.0.1'; // Simple rate limiting: max 60 requests per minute per IP const RATE_LIMIT_WINDOW_MS = 60000; const RATE_LIMIT_MAX_REQUESTS = 60; const requestCounts = new Map<string, { count: number; resetAt: number }>(); function checkRateLimit(ip: string): boolean { const now = Date.now(); const record = requestCounts.get(ip); if (!record || now >= record.resetAt) { requestCounts.set(ip, { count: 1, resetAt: now + RATE_LIMIT_WINDOW_MS }); return true; } if (record.count >= RATE_LIMIT_MAX_REQUESTS) { return false; } record.count++; return true; } try { const server = http.createServer((req, res) => { if (!req.url) { res.statusCode = 400; res.end('Bad Request'); return; } if (req.method !== 'GET') { res.statusCode = 405; res.setHeader('Allow', 'GET'); res.end('Method Not Allowed'); return; } if (!req.url.startsWith('/metrics')) { res.statusCode = 404; res.end('Not Found'); return; } const clientIp = req.socket.remoteAddress || 'unknown'; if (!checkRateLimit(clientIp)) { res.statusCode = 429; res.setHeader('Retry-After', '60'); res.end('Too Many Requests'); return; } try { const body = formatPrometheusMetrics(options); res.statusCode = 200; res.setHeader('Content-Type', 'text/plain; version=0.0.4; charset=utf-8'); res.end(body); } catch (err) { logger.warn('Failed to render /metrics payload', err as Error); res.statusCode = 500; res.end('Internal Server Error'); } }); server.listen(port, host, () => { logger.info(`Prometheus metrics server listening on http://${host}:${port}/metrics`); }); server.on('error', (err) => { logger.warn('Metrics server error', err); }); return server; } catch (err) { logger.warn('Failed to start metrics server', err); return null; } }