"An MCP to access OpenAI's RAG system via API" matching MCP servers:

MCP server for the Stashcat messenger API. Enables AI assistants to read and send messages, manage channels, conversations, files, polls, and more.

Experimental server that implements the Model Context Protocol (MCP) for Nylas API, providing resources, tools, and prompts to help developers integrate email, calendar, and contacts functionality with AI applications.

Enables to interact with Nylas API for email, calendar, and contacts via MCP, providing documentation, code samples, and code generation tools.

Japanese calendar API for AI agents. Provides Rokuyo, Rekichu, Eto, 24 Solar Terms, and fortune judgments. MCP + REST API.

Exposes the Appointment Scheduler API to AI agents as an MCP server, enabling them to list users and services, check availability, book, list, and cancel appointments via natural language.

A stateless MCP server that forwards calendar operations to a CalDAV server, enabling AI assistants to list, search, create, update, delete events, and query free/busy information via encrypted tokens.

A system integrating two independent MCP servers for Google Calendar and Google Tasks APIs, orchestrated by an LLM agent loop with a web dashboard.

Enables interaction with Microsoft Outlook through a unified API, supporting tools for email, calendar, and contacts management via natural language.

Empowers AI assistants with real-world capabilities including note management, Gmail integration, Google Calendar and Tasks management, and Git repository operations through the Model Context Protocol.

Automates HR workflows such as employee onboarding, leave management, meeting scheduling, and ticket handling through natural language, with email notifications and demo data.

MCP server for iCloud (Apple) Calendar access via CalDAV

Enables MCP-compatible clients to act as an AI receptionist for a small medical clinic, handling appointment booking and rescheduling, patient registration, intake, reminders, and FAQ answers.

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.

An MCP server to manage time tracking and time off on Woffu, allowing users to clock in days, view balances, request leave, and check team availability.

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 assistants to interact with Fastmail calendars via CalDAV, allowing them to view, create, update, and delete calendar events using natural language.

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 discover and book local service businesses like barbers, plumbers, and mechanics directly through MCP-compatible tools.

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