Install in 1 click: Make a copy of the template sheet with the script inside. Own Calendar Sync menu, Start here tab, Sample data tab and a first-run box in the sidebar. About 3 minutes to the first event.
Permissions explainer (menu + Start here tab); the template asks for 4 scopes only (no email or profile).
Clear messages for: permission cancelled or unticked, wrong Calendar ID, calendar you cannot edit, empty Events tab.
Pro licence re-checked weekly from the sidebar: refunded or expired keys go back to Free with a plain message; offline never removes Pro.
Get help menu and link, version check (Update available notice), Upgrade to Pro menu and link in the free copy.
Accessible sidebar: labelled fields, keyboard-only use, live status messages, visible focus, works at 300px and phone widths.
1.0.0 (2026-11-01)
First release: two-way sheet and Calendar sync, preview, undo, Event ID column, date and time-zone checks, rate-limit backoff, automatic sync, Calendar and Guests columns.