"Identifying Servers Without Any API Key Configuration" matching MCP servers:

• 

  Nylas API MCP Serverofficial

  nylas-samples

  F

  license

  D

  quality

  C

  maintenance

  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.

  Last updated 2025-03-17

  3

  2

• Nylas API MCP Server

  mcpflow

  F

  license

  D

  quality

  D

  maintenance

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

  Last updated 2025-03-17

  3

• shirabe-calendar-api

  techwell-inc-jp

  A

  license

  -

  quality

  D

  maintenance

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

  Last updated 2026-07-17

  5

  MIT

• stashcat-api-mcp

  dclausen01

  F

  license

  -

  quality

  D

  maintenance

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

  Last updated 2026-04-07

• testCal

  avijeett007

  F

  license

  A

  quality

  D

  maintenance

  Enables users to get and set meeting appointments in Google Calendar.

  Last updated 2024-12-04

  2

  4

• Google Workspace MCP Server

  davidpak

  F

  license

  -

  quality

  D

  maintenance

  Enables AI assistants to manage Google Calendar events and Gmail emails through natural language. Supports creating/listing calendar events with smart color coding, sending/reading emails, and advanced search capabilities across both services.

  Last updated 2025-10-23

• icloud-calendar-mcp-server

  InstaCode

  A

  license

  A

  quality

  C

  maintenance

  Enables Claude (or any MCP client) to read and write events on your iCloud calendars via CalDAV.

  Last updated 2026-07-25

  5

  23

  MIT

• Luma Events MCP Server

  alx1p

  A

  license

  A

  quality

  C

  maintenance

  Discovers events from Luma's public feed and subscribed calendars, with distance filtering, category search, and ICS export. No API key required for basic discovery.

  Last updated 2026-06-28

  4

  MIT

• calendly-mcp

  ericlucianoferreira

  F

  license

  A

  quality

  B

  maintenance

  Enables Claude to schedule, query, and cancel Calendly events via Calendly API v2, allowing direct event management without the public booking form.

  Last updated 2026-07-18

  5

• outlook-mcp

  jagarlamudisrinath

  F

  license

  A

  quality

  B

  maintenance

  Controls the Microsoft Outlook desktop app via COM automation, enabling email, calendar, and contact management without needing Graph API or Azure registration.

  Last updated 2026-07-16

  14

• Fantastical MCP

  jaydenk

  A

  license

  A

  quality

  B

  maintenance

  Enables AI assistants to read and create Fantastical calendar events on macOS using local database access and URL schemes, working entirely offline without API keys or network access.

  Last updated 2026-06-24

  16

  6

  MIT

• mail-calendar-mcp

  mathewcsims

  F

  license

  A

  quality

  B

  maintenance

  Enables full read/write control over Apple Mail.app and Calendar.app on macOS, exposing all configured accounts without per-provider setup.

  Last updated 2026-07-23

  51

• meetergo-mcp

  chill-lichen

  A

  license

  A

  quality

  C

  maintenance

  MCP server that exposes meetergo's scheduling and CRM API as tools for AI assistants, enabling Proton Calendar-backed booking management and contact operations without Google Workspace.

  Last updated 2026-07-08

  37

  BSD 3-Clause

• BitrixMCP

  john7ross

  A

  license

  B

  quality

  C

  maintenance

  Universal MCP server for the Bitrix24 REST API, enabling full read and write access to CRM, tasks, calendar, disk, and more. Supports any MCP client with stdio or Streamable HTTP transport.

  Last updated 2026-07-21

  88

  MIT

• MCP Server Boilerplate

  CaptainCrouton89

  F

  license

  B

  quality

  D

  maintenance

  A starter template for building Model Context Protocol servers that can integrate AI assistants with custom tools, resource providers, and prompt templates.

  Last updated 2025-08-20

  18

  4

  1

• Google Calendar MCP Server

  progrmoiz

  A

  license

  C

  quality

  D

  maintenance

  Enables AI assistants to interact with Google Calendar through a simplified OAuth setup. Supports creating, editing, deleting, and searching calendar events without the complexity of Google Cloud Console configuration.

  Last updated 2025-08-29

  4

  16

  4

  MIT

• M365 MCP

  StuMason

  A

  license

  -

  quality

  A

  maintenance

  MCP server for Microsoft 365 via the Microsoft Graph API, providing read-only access to profile, calendar, email, Teams chats, OneDrive files, and meeting transcripts from any MCP client.

  Last updated 2026-07-28

  23

  2

  MIT

• GoHighLevel MCP Server

  traynewreck

  A

  license

  -

  quality

  D

  maintenance

  Enables AI voice agents like RetellAI and Vapi to directly integrate with GoHighLevel for contact management, calendar availability, and appointment booking without middleware.

  Last updated 2026-02-26

  1

  MIT

• mcp-apple-calendar

  barrettclark

  A

  license

  -

  quality

  C

  maintenance

  A lightweight MCP server for Apple Calendar on macOS that uses a Swift helper to access EventKit directly, enabling event queries without AppleScript or Calendar.app dependency.

  Last updated 2026-06-18

  10

  MIT

• Microsoft MCP

  0xka13b

  A

  license

  -

  quality

  B

  maintenance

  Model Context Protocol servers for Microsoft 365, enabling AI assistants to interact with Calendar, Contacts, OneDrive, Outlook, and SharePoint via the Microsoft Graph API.

  Last updated 2026-06-08

  MIT