Google Ads scripts that watch the account.

// Serann Marketing · Monthly budget pacing alert (read only, changes nothing)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = {
  EMAIL: '__EMAIL__',            // where alerts go, comma separate several
  MONTHLY_BUDGET: __BUDGET__,    // in the account currency
  ALERT_PERCENT: 10              // alert when pacing is off by this much
};

function main() {
  var acc = AdsApp.currentAccount(), tz = acc.getTimeZone(), now = new Date();
  var day = +Utilities.formatDate(now, tz, 'd');
  var y = +Utilities.formatDate(now, tz, 'yyyy'), m = +Utilities.formatDate(now, tz, 'M');
  var daysInMonth = new Date(y, m, 0).getDate();
  var rows = AdsApp.search('SELECT metrics.cost_micros FROM customer WHERE segments.date DURING THIS_MONTH');
  var spend = 0;
  while (rows.hasNext()) spend += Number(rows.next().metrics.costMicros || 0) / 1e6;
  var expected = CONFIG.MONTHLY_BUDGET * day / daysInMonth;
  var projected = day > 0 ? spend / day * daysInMonth : 0;
  var off = expected > 0 ? (spend - expected) / expected * 100 : 0;
  var msg = 'Account: ' + acc.getName() + ' (' + acc.getCustomerId() + ')\n'
    + 'Spend this month: ' + spend.toFixed(2) + ' ' + acc.getCurrencyCode() + '\n'
    + 'Expected by today: ' + expected.toFixed(2) + '\n'
    + 'Projected month end: ' + projected.toFixed(2) + ' against a budget of ' + CONFIG.MONTHLY_BUDGET;
  Logger.log(msg);
  if (Math.abs(off) >= CONFIG.ALERT_PERCENT && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, 'Budget pacing: ' + acc.getName() + ' is ' + Math.abs(off).toFixed(0) + '% ' + (off > 0 ? 'over' : 'under'), msg);
  }
}

// Serann Marketing · Broken landing page checker (read only, changes nothing)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = {
  EMAIL: '__EMAIL__',
  MAX_URLS: 500                  // stay inside the script time limit
};

function main() {
  var urls = {};
  collect("SELECT ad_group_ad.ad.final_urls FROM ad_group_ad WHERE ad_group_ad.status = 'ENABLED' AND ad_group.status = 'ENABLED' AND campaign.status = 'ENABLED'",
    function (r) { return r.adGroupAd.ad.finalUrls; }, urls);
  collect("SELECT asset_group.final_urls FROM asset_group WHERE asset_group.status = 'ENABLED' AND campaign.status = 'ENABLED'",
    function (r) { return r.assetGroup.finalUrls; }, urls);
  var bad = [], n = 0;
  for (var u in urls) {
    if (n++ >= CONFIG.MAX_URLS) break;
    try {
      var code = UrlFetchApp.fetch(u, { muteHttpExceptions: true, followRedirects: true }).getResponseCode();
      if (code >= 400) bad.push(code + '  ' + u);
    } catch (e) { bad.push('No response  ' + u); }
  }
  Logger.log('Checked ' + Math.min(n, CONFIG.MAX_URLS) + ' URLs, ' + bad.length + ' with errors');
  if (bad.length && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, bad.length + ' broken landing pages in ' + AdsApp.currentAccount().getName(), bad.join('\n'));
  }
}

function collect(query, pick, out) {
  var rows = AdsApp.search(query);
  while (rows.hasNext()) {
    var list = pick(rows.next()) || [];
    for (var i = 0; i < list.length; i++) out[String(list[i]).split('#')[0]] = true;
  }
}

// Serann Marketing · Search terms with spend and no conversions (read only)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = {
  EMAIL: '__EMAIL__',
  MIN_COST: __MINCOST__,         // in the account currency
  DATE_RANGE: 'LAST_30_DAYS'
};

function main() {
  var q = 'SELECT search_term_view.search_term, campaign.name, ad_group.name, metrics.clicks, metrics.cost_micros, metrics.conversions'
    + ' FROM search_term_view WHERE segments.date DURING ' + CONFIG.DATE_RANGE
    + ' AND metrics.conversions = 0 AND metrics.cost_micros > ' + Math.round(CONFIG.MIN_COST * 1e6)
    + ' ORDER BY metrics.cost_micros DESC LIMIT 200';
  var rows = AdsApp.search(q), out = [], total = 0;
  while (rows.hasNext()) {
    var r = rows.next(), cost = Number(r.metrics.costMicros) / 1e6;
    total += cost;
    out.push(cost.toFixed(2) + '  |  ' + r.metrics.clicks + ' clicks  |  ' + r.searchTermView.searchTerm + '  |  ' + r.campaign.name + ' > ' + r.adGroup.name);
  }
  Logger.log(out.join('\n'));
  if (out.length && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, out.length + ' search terms spent ' + total.toFixed(2) + ' without a conversion',
      'Review these before adding negatives:\n\n' + out.join('\n'));
  }
}

// Serann Marketing · Daily drop and spike alert (read only, changes nothing)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = {
  EMAIL: '__EMAIL__',
  CHANGE_PERCENT: 40             // alert when a metric moves this much
};

function main() {
  var acc = AdsApp.currentAccount(), tz = acc.getTimeZone();
  function day(n) { return Utilities.formatDate(new Date(Date.now() - n * 864e5), tz, 'yyyy-MM-dd'); }
  var rows = AdsApp.search("SELECT segments.date, metrics.clicks, metrics.cost_micros, metrics.conversions FROM customer WHERE segments.date BETWEEN '" + day(29) + "' AND '" + day(1) + "'");
  var by = {};
  while (rows.hasNext()) {
    var r = rows.next();
    by[r.segments.date] = { clicks: Number(r.metrics.clicks), cost: Number(r.metrics.costMicros) / 1e6, conv: Number(r.metrics.conversions) };
  }
  var y = by[day(1)] || { clicks: 0, cost: 0, conv: 0 }, base = { clicks: 0, cost: 0, conv: 0 };
  [8, 15, 22, 29].forEach(function (n) { var x = by[day(n)] || { clicks: 0, cost: 0, conv: 0 }; base.clicks += x.clicks / 4; base.cost += x.cost / 4; base.conv += x.conv / 4; });
  var notes = [];
  function chg(a, b) { return b > 0 ? (a - b) / b * 100 : 0; }
  if (chg(y.clicks, base.clicks) <= -CONFIG.CHANGE_PERCENT) notes.push('Clicks ' + y.clicks + ' against a usual ' + base.clicks.toFixed(0));
  if (chg(y.conv, base.conv) <= -CONFIG.CHANGE_PERCENT) notes.push('Conversions ' + y.conv.toFixed(1) + ' against a usual ' + base.conv.toFixed(1));
  if (chg(y.cost, base.cost) >= CONFIG.CHANGE_PERCENT) notes.push('Cost ' + y.cost.toFixed(2) + ' against a usual ' + base.cost.toFixed(2));
  Logger.log(notes.length ? notes.join('\n') : 'Nothing unusual yesterday');
  if (notes.length && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, 'Unusual day in ' + acc.getName() + ' (' + day(1) + ')', notes.join('\n') + '\n\nCompared with the same weekday over the last four weeks.');
  }
}

// Serann Marketing · Disapproved ads report (read only, changes nothing)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = { EMAIL: '__EMAIL__' };

function main() {
  var q = "SELECT campaign.name, ad_group.name, ad_group_ad.ad.id FROM ad_group_ad"
    + " WHERE ad_group_ad.status = 'ENABLED' AND ad_group.status = 'ENABLED' AND campaign.status = 'ENABLED'"
    + " AND ad_group_ad.policy_summary.approval_status = 'DISAPPROVED'";
  var rows = AdsApp.search(q), out = [];
  while (rows.hasNext()) {
    var r = rows.next();
    out.push(r.campaign.name + ' > ' + r.adGroup.name + '  |  ad ID ' + r.adGroupAd.ad.id);
  }
  Logger.log(out.length + ' disapproved ads\n' + out.join('\n'));
  if (out.length && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, out.length + ' disapproved ads in ' + AdsApp.currentAccount().getName(),
      out.join('\n') + '\n\nOpen Ads, filter by Status: Disapproved, to see the policy reason.');
  }
}

// Serann Marketing · Shopping products with spend and no sales (read only)
// https://serann.marketing/tools/google-ads-scripts/
var CONFIG = {
  EMAIL: '__EMAIL__',
  MIN_COST: __MINCOST__,         // in the account currency
  DATE_RANGE: 'LAST_30_DAYS'
};

function main() {
  var q = 'SELECT segments.product_item_id, segments.product_title, metrics.clicks, metrics.cost_micros, metrics.conversions'
    + ' FROM shopping_performance_view WHERE segments.date DURING ' + CONFIG.DATE_RANGE
    + ' AND metrics.conversions = 0 AND metrics.cost_micros > ' + Math.round(CONFIG.MIN_COST * 1e6)
    + ' ORDER BY metrics.cost_micros DESC LIMIT 200';
  var rows = AdsApp.search(q), out = [], total = 0;
  while (rows.hasNext()) {
    var r = rows.next(), cost = Number(r.metrics.costMicros) / 1e6;
    total += cost;
    out.push(cost.toFixed(2) + '  |  ' + r.metrics.clicks + ' clicks  |  ' + r.segments.productItemId + '  |  ' + r.segments.productTitle);
  }
  Logger.log(out.join('\n'));
  if (out.length && CONFIG.EMAIL.indexOf('@') > 0) {
    MailApp.sendEmail(CONFIG.EMAIL, out.length + ' products spent ' + total.toFixed(2) + ' without a sale', out.join('\n'));
  }
}