https://developers.google.com/apps-script

a modern JavaScript dialect

Guide

https://developers.google.com/codelabs/apps-script-fundamentals-1#0

API Reference

https://developers.google.com/apps-script/reference/spreadsheet

Google Sheets API

A1 notation https://developers.google.com/sheets/api/guides/concepts#a1_notation

Google Workspace

https://github.com/googleworkspace

Get started https://developers.google.com/workspace/guides/getstarted-overview