ridafkih/keeper.sh

Calendar sync tool & universal calendar MCP server. Aggregate, sync and control calendars on Google, Outlook, Office 365, iCloud, CalDAV or ICS.

What it solves

Keeper.sh is a calendar syncing tool designed to prevent scheduling conflicts when managing multiple calendars (e.g., business, work, and personal). It allows users to aggregate events from various sources and push them to one or more destination calendars so that time slots remain aligned across all platforms.

How it works

The system uses a two-part engine: ingestion and pushing. Ingestion pulls events from sources (Google, Outlook, iCloud, Fastmail, CalDAV, or iCal/ICS links) into a local database. Pushing then reconciles these events with destination calendars. It tracks deletions using mapping rows to ensure that when an event is removed from the source, it is also removed from the destination. For Google and Outlook, it uses provider sync tokens for incremental updates rather than refetching all data.

Who it’s for

It is for individuals who manage multiple calendar accounts and need a centralized way to sync events across them to avoid double-booking, as well as developers who want an open-source, self-hostable solution with API access.

Highlights

  • Broad Integration: Supports Google Calendar, Outlook, iCloud, Fastmail, and CalDAV as both sources and destinations.
  • AI Agent Ready: Includes an MCP (Model Context Protocol) server and REST API, allowing AI agents to manage calendars through a single interface.
  • Sovereignty: Fully open-source (AGPL-3.0) and self-hostable, giving users full control over their data.
  • Privacy Controls: Offers per-source controls to strip sensitive event details (names, descriptions, locations) and replace them with templates.

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