"Hack The Box" matching MCP servers:

Enables AI assistants to manage events, venues, organizers, and tickets on WordPress sites via CRUD operations.

MCP server for Open-Xchange & standards-based mail: email (IMAP/SMTP), Sieve filters, CalDAV calendar, CardDAV contacts, free/busy.

Native macOS Calendar & Reminders MCP server with 25 tools via Apple EventKit. Supports recurring events, location-based reminder triggers, multi-keyword search, duplicate detection, conflict checking, and batch operations across iCloud/Google/Exchange calendars.

Enables AI assistants to manage Microsoft Outlook Desktop (Classic) calendar and email through local COM automation, without Microsoft Graph or Entra registration.

Evaluates whether a meeting is worth attending, heavily weighted toward no, and provides time cost analysis, productivity impact, email viability score, and a polite decline template.

Enables retrieval of the Hindu almanac for a given date and place, including tithi, nakshatra, yoga, karana, vaara, sunrise/sunset, and auspicious or inauspicious muhurta periods.

An OAuth-secured remote MCP server (22 tools) that lets Claude, ChatGPT, and Codex search All-In Summit attendee profiles, explore the live agenda, check sessions and meetings, detect scheduling conflicts, and export a calendar. Account-changing actions are only prepared for review, with the user confirming each request in the browser before any event API call is made.

Measures the shape of idle time in a booking calendar. Separates gaps that can actually be sold from structurally unsellable dead time, accounting for turnover time and the booking start grid. Fully offline, no API key required.

Enables users to describe workouts in plain English and have them created as structured Garmin Connect workouts with pace, HR, power, cadence targets, and repeat blocks. Also provides full workout lifecycle management including listing, updating, deleting, and scheduling to the calendar.

Provides real, official public holiday data for ~100 countries with tools to list holidays for a year and check if a specific date is a holiday. Free, no API key required, powered by Nager.Date.

Enables AI agents to read and send email, handle attachments and manage calendar invitations through their own IMAP/SMTP mailboxes, with per-mailbox sender and recipient allow lists and automatic HTML-to-Markdown conversion. It runs as a single self-hosted Docker container, exposing the same tools over MCP and REST.

MCP server for the Shiftyasan public solver API, letting AI agents validate and solve shift-scheduling problems, with async job polling for large cases.

MCP server that wraps the AddEvent Calendar & Events API v2, allowing Claude to create, search, retrieve, update, and delete events, calendars, and RSVP attendees, plus list timezones.

Enables AI assistants to interact with Fastmail services, providing tools for comprehensive email management, contact searching, and calendar event coordination via the JMAP API. It supports advanced features like threaded conversations, attachment handling, and bulk mailbox operations through natural language.

Create scheduling polls (like Doodle) from AI agents. Find the best time for meetings, dinners, and events. 5 tools: create_poll, get_poll, vote_on_poll, get_results, finalize_poll. No authentication required.

Local-first Microsoft Outlook MCP server: a single Go binary that manages calendar events and mail through the Microsoft Graph API over stdio, with tokens stored in the OS keychain and no Entra ID app registration required. Exposes four aggregate tools (calendar, mail, account, system) dispatched by an operation verb, with multi-account support and read-only and mail-gating modes.

Enables agents to interact with a clinic booking API, including listing specialties, doctors, and a patient's appointments, and booking or cancelling appointments when the active profile permits, while preserving the caller's authority and screening tool descriptions for safety.

A minimal MCP server that exposes a single tool, day_in_week, to return the current weekday name.

Enables AI agents to interact with Microsoft Teams through Microsoft Graph API, using delegated device-code authentication to act on behalf of the user.

MCP server for the Crown Town Compost customer portal that lets you check pickups, invoices, and upcoming collections, skip services, report missed pickups, and update account details through natural language.