Keeper.sh is unclaimed —

Keeper.sh

All of your calendars in-sync.·keeper.sh

From $5/mo · Free plan · Open source See pricing ↓

Keeper.sh is an open-source calendar event syncing tool that keeps personal, work, business, and school calendars synchronized automatically. It uses a pull-compare-push architecture to sync events between Google Calendar, Outlook, Apple Calendar, FastMail, CalDAV, and ICS/iCal feeds. It offers privacy-first syncing, sharing only busy/free blocks by default, and provides an aggregated iCal feed and an MCP server for AI agent calendar access.

What it's for

Sync events between personal, work, business and school calendarsAggregate multiple calendars into a single iCal feed for external sharingPull events from read-only ICS/iCal feeds as a sync sourceGive AI agents access to calendar data via MCP server with OAuth 2.1Self-host the syncing service via Docker Compose

Features 12

Aggregated iCal feed generation for sharing availability externally
API and MCP access
Configurable sync interval (30 minutes on Free, 1 minute on Pro)
Conflict/discrepancy reconciliation to prevent orphan events
Event filters and exclusions
Granular controls for event titles, descriptions, and locations
MCP (Model Context Protocol) server for AI agent calendar access via OAuth 2.1
OAuth, ICS, and CalDAV account linking
Privacy-first sharing of only busy/free time blocks by default
Self-hostable with Docker Compose (standalone, services-only, or individual containers)
Sync event name, description, location, status, and attendees
Universal calendar sync across Google Calendar, Outlook, Apple Calendar, FastMail, CalDAV, and iCal feeds

At a glance

free tieropen sourceself-hostableAPI

TypeWeb app

DeploymentHybrid

PlatformsWeb

Forindividuals wanting personal calendar sync, power users needing fast syncs

CompanyKeeper.sh

Integrations

Microsoft 365OutlookiCloudGoogle CalendarCalDAVFastMail

Pricing

Self-hosting via the GitHub repository is available as a free alternative to the hosted plans.

FreeFree

For personal use and getting started with calendar sync.

Sync interval every 30 minutes; up to 2 linked accounts; up to 3 sync mappings; API & MCP access 25 calls/day

Pro$5/mo

For power users who need fast syncs, advanced feed controls, and unlimited syncing.

Sync interval every 1 minute; unlimited linked accounts and sync mappings; includes advanced feed customization and priority support