"Examples of MCPs (Microservices Communication Protocols) That Do Not Require API Keys" matching MCP connectors:

Reassign: a circular 24-hour calendar and time-tracking copilot with ADHD-friendly scheduling.

Business days, meeting overlap and recurrence expansion, deterministic. 3 of 5 tools free.

Schedules and results for the 2026 FIFA World Cup in natural language: today's matches, kickoff time

electron.dance MCP server: upcoming gigs, community links, RSVP, and Spotify top tracks.

Chilean online mental-health clinic (Spanish): articles, professionals, availability, tests.

take-the-meeting MCP — wraps StupidAPIs (requires X-API-Key)

Calendly MCP Pack — wraps the Calendly API v2 for scheduling data.

Orbit Zürich: Workshop-Räume, Preise und freie Slots abfragen, Buchungsanfragen stellen.

Scheduling, availability, clients, billing and CRM for appointment-based services.

Hosted MCP server for the Healthie EHR & telehealth API: patients, appointments, charting, tasks.

Members-run AI builder space on Floor 10, Frontier Tower SF. 138 tools: events, news, directory.

Calendar API for AI agents: events, availability, Google/Microsoft setup, scheduling, and iCal.

Live KARVE Pilates class schedule and availability in Jeddah, with booking links. Read-only.

Find public EventMatey events that organisers have approved for AI discovery.

Book, reschedule, and cancel home services (cleaning, lawn, snow) via phone OTP authentication.

Personalized timing intelligence for AI agents — ask 'should I do X on this date?'

Surf park sessions schedule availability and notifications for wave park surfers worldwide

AI-powered virtual assistant that connects to Gmail, Outlook, Slack, Salesforce, HubSpot, Google Calendar, DocuSign, QuickBooks, and 20+ other services. Manage your entire professional life through a single Claude conversation — email, calendar, CRM, documents, travel, expenses, and more.

Open-source MCP server that gives AI agents access to real email and calendar in one npm install. Solves the problem of AI agents hitting a wall when they need your inbox.

Heldly reads your Google Calendar directly, places tentative holds on every host's calendar, and emails the invitee a one-click picker. The moment the invitee picks, Heldly confirms the chosen slot and deletes the siblings across every host's calendar in the same request. No reusable booking page, no in-app form, no calendar cleanup.