I had the issue that I am using google calendar for my personal calendar while needing to keep my work calendar in a microsoft account up to date. This little Vibe coded app does the job for me.
It is a macOS menu bar app, that uses the calendar framework to sync events between multiple calendars. You can setup multiple syncs, with different filters and time windows.
Feel free to clone the code and build it after installing xcode and running the ./install.sh script or download the latest release from the releases page.
This app is vibe-coded - use at your own risk.
- One-way sync from source → target calendar
- Recurrence + exceptions with per-occurrence mapping
- Filters: include/exclude, regex, ignore other tuples
- Weekday/time windows; blocker-only mode
- Tagging in Event Notes for safe sync even from multiple computers
- Diagnostics logs (levels), filter and export (JSON/Text)
- Scheduler with configurable interval; manual Sync Now
- Sending tasks that are due within the sync time interval to a webhook URL
- Run at Login toggle
If you want to run the app on multiple computers, make sure that you export the settings and import them on the other computers. The explicit IDs from the sync tuples are used to identify the events and align them to the correct events on the other computers.
You need to give the app the permissions to access your calendar. After this the app should restart. If it doesn't restart, you need to manually restart it.
I myself have not much experience with writing Swift and SwiftUI, so the code is not perfect. This app was vibe-coded with Cursor. It took around 20 hours to develop this app.
The Model used was mainly GPT-5 in Thinking Mode.
It took around 160 separate prompts to bring it to a usable state which turned out to be around one month of Cursor Pro included requests. (around 23$ of API costs)
MIT