One calendar, tied to the people you actually plan with.
Musubi pulls your Google, Apple, Outlook and CalDAV calendars into one view and syncs both ways — then shares only with the handful of people you invite. No feeds, no ads, no data sold. Open source and self-hostable.
What it's actually for.
.ics the day you decide to leave.Three views. That's the whole app — on purpose.
Your calendar, before you open the app.
The next thing and the shape of the month, sitting quietly on your home screen.
Resize them from a sparse glance into a detailed view. Recurring events become real occurrences, every colour follows its calendar, and light or dark mode changes with the rest of your phone.
Android now · iOS next
Your other calendars are welcome here.
Work lives in Google. Family lives in iCloud. Musubi ties them into one view — and syncs both ways, so nothing you write here gets left behind there.
And inside Musubi, events are set free: one dinner can live in your calendar, your partner's, and the family one — linked, not copied. Edit it once, it changes everywhere. Recurring events, exceptions and all, survive the round trip.
View Google Calendar access details
Musubi can connect to one or more Google Calendar accounts and provide two-way synchronization and calendar management.
With your permission, Musubi can:
- display your Google calendars and their events;
- create, update, and delete events;
- create, rename, recolor, and delete calendars you own;
- synchronize changes between Google Calendar and Musubi.
Musubi performs these actions only when you initiate them through the application or when synchronization has been explicitly enabled.
You can disconnect a Google account at any time. Disconnecting removes the stored Google credentials and synchronized copies of that account's calendars and events from Musubi.
See whose plans are whose, at a glance.
Every calendar you make gets its own colour, so one look at the month tells you what's work, what's family, what's the climbing crew. Five muted tones, none louder than the rest — their names borrowed from old Japanese pigments.
What we won't do, in plain words.
Your calendar knows where you'll be and who with. That's not data to mine — so Musubi is built not to.
Here's what that means, in plain words — and you can verify every line in the source.
Built in the open. Yours to read, fork, and run.
A calendar holds quiet things. So the code that holds them should be readable by anyone who cares to look.
Every line of Musubi — app, server, sync protocol — lives on GitHub under the MIT License. Self-host the whole thing, audit every endpoint, or just lurk. We won't mind.
docker compose up. Your knots, your hardware.The knot is still being tied.
Everything below is in the open on our roadmap — marked honestly as work in progress, not promised for next Tuesday.
The things people ask.
What is Musubi?
Musubi is an open-source shared calendar. It pulls your Google, Apple, Outlook and CalDAV calendars into one view that syncs both ways, then lets you share a calendar with just the handful of people you invite — your partner, the household, the climbing crew. No feeds, no ads, no social layer.
Which calendars can I connect?
Google Calendar, Apple iCloud, Outlook and Microsoft 365, and any CalDAV server (Nextcloud, Fastmail, Radicale). All of them sync two ways, so anything you write in Musubi shows up in the original calendar, and changes there flow back. Multiple accounts are welcome, and read-only calendars stay read-only.
Is Musubi free?
Yes — it's free during the open beta, with no trial countdown and no subscription. If optional paid extras ever arrive, the calendar itself stays useful without them. And because Musubi is open source, you can always self-host it for the cost of your own server.
What happens to my data? Do you sell it?
Never. There are no ads and nothing is sold. The hosted service runs on EU infrastructure over HTTPS with restricted access. Your calendar is shared only through an invite link you explicitly create — there's no discover, no friends-of-friends, no activity feed. You can read exactly what we do with your data in the Privacy Policy.
Can I self-host Musubi?
Yes. Every part of Musubi — app, server, and sync protocol — is open source under the MIT License and lives on GitHub. Bring your own server and run the whole thing with a single docker compose up. Your knots, your hardware.
How does sharing work?
You make a calendar per relationship and send an invite link to the few people who should see it. That's the only way anyone joins — there's no network to be discovered on. One event can live in several shared calendars at once, linked rather than copied, so editing it once updates it everywhere.
Is there an iPhone app?
Android is in open beta on Google Play now. The iOS build is done and in testing — open testing on the App Store lands shortly. It's the same app with the same calm.
Will Musubi notify me constantly?
No. You get one reminder — the one you actually asked for. No engagement pings, no 11 PM nudges, no notifications designed to pull you back in.
A few good emails. Only when there’s something to say.
Early access, thoughtful product news, and the occasional note from behind the screens.
Sent rarely — only when there is something worth opening. Po málu a kvalitně.