function main() {
  // Threshold Settings
  var campaignBudgetThreshold = 0.8; // Alert when 80% of the budget is spent
  var sendEmailAlerts = true; // Set to false to disable emails
  var recipientEmail = "your_email@example.com";

  // Get all active campaigns
  var campaignIterator = AdsApp.campaigns()
      .withCondition("Status = ENABLED")
      .get();

  while (campaignIterator.hasNext()) {
    var campaign = campaignIterator.next();
    var campaignName = campaign.getName();
    var budget = campaign.getBudget().getAmount();
    var spendToDate = campaign.getStatsFor("TODAY").getCost();

    var spentPercentage = spendToDate / budget;

    if (spentPercentage >= campaignBudgetThreshold && sendEmailAlerts) {
      var subject = "Budget Alert: " + campaignName;
      var body = "Campaign " + campaignName + " has spent " + (spentPercentage * 100).toFixed(0) + "% of its budget.";
      MailApp.sendEmail(recipientEmail, subject, body);
    }
  }
}