Send New Google Sheets Rows to LeadCentre

Something watches your sheet for new rows and posts each one to your LeadCentre webhook URL. LeadCentre matches your column headings to its fields and creates a lead. It works in one direction: updates in LeadCentre don't change the sheet, and changing a row after it's sent doesn't change the lead.

Which option to choose

• Zapier: Google Sheets with New Spreadsheet Row, then Webhooks by Zapier, which isn't on Zapier's Free plan. The simplest if you already pay for it. Zapier's help says only rows added at the bottom count as new, and that deleting or sorting rows can cause missed or repeated runs.
• Make: Google Sheets Watch New Rows, then HTTP Make a request. It checks on a schedule, and the shortest interval depends on your plan. Make warns that a blank row stops it processing the rows after it.
• Apps Script: free and yours to control, but you look after it. It's the one to pick if rows get sorted or deleted, or if you'd rather not pay for another tool.

Don't expect any of these to be immediate. Zapier and Make depend on Google and their own schedules, and the script runs on a timer. If the leads start in a form or an ad, connect that source directly if you can, and keep the sheet as your record.

The Apps Script option

This checks your sheet on a timer and posts any row with an empty Sent column, then fills that cell in. A timed trigger is the right fit, because Google doesn't fire edit triggers for rows added by scripts or API requests, and many tools add rows that way.

var SHEET_NAME = 'Leads';

function sendNewRows() {
  var props = PropertiesService.getScriptProperties();
  var url = props.getProperty('LEADCENTRE_URL');
  var sheet = SpreadsheetApp.getActive().getSheetByName(SHEET_NAME);
  var rows = sheet.getDataRange().getValues();
  var headers = rows[0];
  var sentColumn = headers.indexOf('Sent');
  if (sentColumn < 0) throw new Error('Add a Sent column');
  var count = 0;
  for (var i = 1; i < rows.length && count < 50; i++) {
    if (rows[i][sentColumn] || rows[i].join('') === '') continue;
    var lead = {};
    headers.forEach(function (name, column) {
      if (name && column !== sentColumn) lead[name] = rows[i][column];
    });
    var response = UrlFetchApp.fetch(url, {
      method: 'post',
      contentType: 'application/json',
      payload: JSON.stringify(lead),
      muteHttpExceptions: true
    });
    count++;
    if (response.getResponseCode() !== 200) continue;
    var result = JSON.parse(response.getContentText()).results[0];
    if (result !== 'test') {
      sheet.getRange(i + 1, sentColumn + 1).setValue(new Date());
    }
  }
}

A row sent during a test isn't marked as sent, so it goes again once you stop listening. Each run sends up to 50 rows, which stays well inside LeadCentre's limit of 120 a minute.

A few things to know: the timer runs under the account of whoever created it, so it stops if that person loses access. Anyone who can edit the sheet can open the script and find your URL, so limit who can edit.