CTS MCP Server

/** * Tool Wrapper - Integrates Tier 2C Infrastructure * * Wraps tool handlers with: * - Result caching (Tier 2C.5) * - Observability (Tier 3.3) * - Configuration (Tier 2C.6) * - Error handling (Tier 2C.2) */ import { ToolHandler } from '../types.js'; import { globalCache } from '../cache/result-cache.js'; import { logger, metrics } from '../observability/index.js'; export interface WrapperOptions { toolName: string; cacheable?: boolean; bypassCacheParam?: string; // Parameter name to bypass cache (e.g., '_bypassCache') } /** * Wrap tool handler with caching and observability */ export function wrapToolHandler( handler: ToolHandler, options: WrapperOptions ): ToolHandler { const { toolName, cacheable = false, bypassCacheParam = '_bypassCache' } = options; return async (args: Record<string, unknown>) => { const startTime = performance.now(); let success = true; let cacheHit = false; let result: any; try { // Check if cache should be bypassed const bypassCache = cacheable && args[bypassCacheParam] === true; delete args[bypassCacheParam]; // Remove from args before processing // Check cache if enabled and not bypassed if (cacheable && !bypassCache) { const cacheKey = globalCache.generateKey(toolName, args); result = globalCache.get(cacheKey); if (result !== undefined) { cacheHit = true; logger.debug('Cache hit', { tool: toolName, key: cacheKey }); } else { logger.debug('Cache miss', { tool: toolName, key: cacheKey }); } } // Execute tool if not cached if (result === undefined) { result = await handler(args); // Store in cache if cacheable if (cacheable && !bypassCache) { const cacheKey = globalCache.generateKey(toolName, args); globalCache.set(cacheKey, result); logger.debug('Result cached', { tool: toolName, key: cacheKey }); } } // Add cache metadata to result if (cacheable && typeof result === 'object' && result !== null) { result.cached = cacheHit; } return result; } catch (error) { success = false; logger.error('Tool execution failed', { tool: toolName, error: error instanceof Error ? error.message : String(error), }); throw error; } finally { // Record metrics const duration = performance.now() - startTime; metrics.recordToolExecution(toolName, duration, success, cacheHit); logger.info('Tool executed', { tool: toolName, duration: Math.round(duration * 100) / 100, success, cacheHit: cacheable ? cacheHit : undefined, }); } }; } /** * Convenience function for cacheable tools */ export function withCache(toolName: string, handler: ToolHandler): ToolHandler { return wrapToolHandler(handler, { toolName, cacheable: true }); } /** * Convenience function for non-cacheable tools */ export function withObservability(toolName: string, handler: ToolHandler): ToolHandler { return wrapToolHandler(handler, { toolName, cacheable: false }); }