MCP Time Server Node

import { formatInTimeZone } from 'date-fns-tz'; import { ValidationError, TimezoneError } from '../adapters/mcp-sdk'; import { CacheTTL } from '../cache/timeCache'; import type { GetCurrentTimeParams, GetCurrentTimeResult } from '../types'; import { getConfig } from '../utils/config'; import { debug } from '../utils/debug'; import { resolveTimezone } from '../utils/timezoneUtils'; import { validateTimezone, validateStringLength, LIMITS } from '../utils/validation'; import { withCache } from '../utils/withCache'; /** * Generates cache key for current time request * Note: Now only used for generating the raw cache key for withCache */ export function getCacheKey(timezone: string, format: string, includeOffset: boolean): string { return `current_${timezone}_${format}_${includeOffset}`; } /** * Formats time with the appropriate options based on parameters */ export function formatTimeWithOptions( now: Date, timezone: string, params: GetCurrentTimeParams, defaultFormat: string ): string { if (params.include_offset !== false && !params.format) { // Default format includes offset return formatInTimeZone(now, timezone, defaultFormat); } else if (params.include_offset === false && params.format) { // Custom format without offset - use the format as-is return formatInTimeZone(now, timezone, params.format); } else { // Use format string as provided (default or custom) return formatInTimeZone(now, timezone, defaultFormat); } } /** * Builds the time result object */ export function buildTimeResult( now: Date, formattedTime: string, timezone: string ): GetCurrentTimeResult { // Get offset separately for the result object const offset = timezone === 'UTC' ? 'Z' : formatInTimeZone(now, timezone, 'XXX'); return { time: formattedTime, timezone: timezone, offset: offset, unix: Math.floor(now.getTime() / 1000), iso: formatInTimeZone(now, timezone, "yyyy-MM-dd'T'HH:mm:ss.SSSXXX"), }; } /** * Handles format errors from date-fns */ export function handleFormatError(error: unknown, format: string): never { if (error instanceof RangeError || (error instanceof Error && error.message.includes('format'))) { throw new ValidationError(`Invalid format: ${error.message}`, { format, error: error.message }); } throw error; } export function getCurrentTime(params: GetCurrentTimeParams): GetCurrentTimeResult { debug.timezone('getCurrentTime called with params: %O', params); // Validate format string length first if (params.format) { validateStringLength(params.format, LIMITS.MAX_FORMAT_LENGTH, 'format'); } // Resolve timezone with proper empty string handling const config = getConfig(); const timezone = resolveTimezone(params.timezone, config.defaultTimezone); const formatStr = params.format ?? "yyyy-MM-dd'T'HH:mm:ss.SSSXXX"; const includeOffset = params.include_offset !== false; // Use withCache wrapper instead of manual cache management return withCache(getCacheKey(timezone, formatStr, includeOffset), CacheTTL.CURRENT_TIME, () => { // Validate timezone if (!validateTimezone(timezone)) { throw new TimezoneError(`Invalid timezone: ${timezone}`, timezone); } const now = new Date(); try { // Format time with appropriate options const formattedTime = formatTimeWithOptions(now, timezone, params, formatStr); // Build result const result = buildTimeResult(now, formattedTime, timezone); return result; } catch (error: unknown) { handleFormatError(error, params.format ?? formatStr); } }); }