"MCP servers that work without API keys" 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.

Enables users to schedule 90-minute ultradian focus blocks, triage incoming interruptions against contact priority thresholds, and capture execution checkpoints for instant resumption.

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

Enables users to schedule 90-minute ultradian focus blocks, triage incoming interruptions using contact priority and urgency thresholds, and capture execution checkpoints for instant task resumption.

Enables AI agents and scripts to read and manage events on your account — guest lists with questionnaire answers, CSV export, check-in, approvals, invites and Text Blasts — through your own signed-in Chrome session, with no public API or official integration required. Runs locally over stdio, streamable HTTP, a REST API with OpenAPI docs, and a Python client.

Enables AI agents and scripts to manage bookings, provider assignment, rescheduling, cancellations, customers, quotes, invoices, and dashboard data through a self-hosted API and MCP interface using your own Chrome session.

Enables AI agents and scripts to run a Booksy Biz account through your own signed-in Chrome session, exposing 28 tools for appointments, open slots, time off, clients, services, staff, reviews, Message Blasts, and reports over MCP, REST, or Python. Read-only mode and confirmation-gated client-facing actions let you plan schedules, reschedules, and outreach with human approval.

Self-hosted Fresha API and MCP server in Python: 17 Fresha tools for appointments, clients, services, team and reviews, on the session of your own Chrome. Personal use.

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.

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.

Provides Japanese business day calculations: add or subtract business days, count between dates, check whether a date is a business day, and reverse-calculate deadlines. Handles national holidays and year-end periods fully offline with no API keys required.

Provides Japanese national holidays, wareki (era) conversion, and date information. Works fully offline with no API keys required.

Enables Claude to read appointments, invoices, quotes, and work requests from a Jobber Client Hub. Read-only, uses a local browser bridge to access the customer portal.

An unofficial MCP server that enables AI assistants to work with Yandex Tracker, Yandex Mail, and Yandex Calendar on the user's behalf, supporting reading, writing, and workflow automations such as meeting follow-ups, standups, and email-to-task creation.

Enables users to find available appointment slots from a public resource schedule over an inclusive date range, applying booking-window rules when requested. It returns wall-clock times and flags truncated result sets, operating read-only without account or API key.

MCP server for the eRezo API that enables managing professional contacts and events directly from Claude, including listing, creating, updating, and deleting contacts, as well as event registration.

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

MCP server for Claude to access on-premises Outlook/Exchange mailboxes via EWS with NTLM authentication, providing tools for email, calendar, and contact management without relying on Microsoft 365 or Graph API.