Google Apps Script Classes: SpreadsheetApp, GmailApp, DriveApp Explained

Apps Script exposes Google services as global classes: SpreadsheetApp, GmailApp, DriveApp, CalendarApp, DocumentApp, FormApp, and UrlFetchApp for everything else on the internet.

Methods are synchronous; there is no async/await in the runtime. Understanding the object hierarchy—Spreadsheet > Sheet > Range—prevents off-by-one range bugs and #REF errors at scale.

This reference highlights the methods used in 80% of client automations with pointers to advanced guides like /blog/apps-script-rest-api-guide for non-Google APIs.

Example code

function summarizeActiveSheet() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sh = ss.getSheetByName('Orders') || ss.getActiveSheet();
  const values = sh.getDataRange().getValues();
  const headers = values.shift();
  const count = values.filter(function (row) { return row[0]; }).length;
  Logger.log('%s rows on %s', count, sh.getName());
  return { sheet: sh.getName(), rows: count, headers: headers };
}

FAQ