Yes! You can set up a webhook in Sendy, so that you can add a new row into Google Sheets whenever you get a new mailing list subscriber.

CAUTION: If you’re running a double opt-in list, and the user is using Google Mail, then the ‘new subscriber’ notification is sometimes sent TWICE: once when they click on the confirmation link, and once by Google itself (because it does some snooping on the link to check that it’s safe.)


To install, follow these steps.

1. Set up the script in Google Docs

  1. Create a Google Sheet with 5 columns:

    • Date/Time

    • Trigger

    • Subscriber Name

    • List

    • Source URL (or a custom field of your choice)

  2. Go to Tools → Script Editor.

  3. Create the three files listed below:




  4. Save.

  5. Deploy → New Deployment:

    • Type: Web app

    • Description: (anything you like)

    • Execute as: (you)

    • Who has access: Anyone

  6. Click Deploy. You’ll then need to authenticate to Google to allow the script to make changes to your spreadsheet.

  7. You should get a URL to the Web app that usually looks like:…/exec. Copy this URL to paste into Sendy.

NOTE: When you make any future updates to the script, you need to redeploy it. In Script Editor, click Deploy → Manage Deployments. Then, Edit the active deployment. select Version → New Version, to update the Deployment with the current version of the code, and click Deploy.

2. Increase the webhook field length in Sendy

You also need to increase Sendy’s rules.endpoint db column size to 255 chars, because the Google Webhook URL is too long to fit in Sendy’s default 100 character limit.

An example of how to do this:

$ sudo su -
$ mysql

mysql> use sendy;
mysql> select endpoint from rules;
mysql> alter table rules modify endpoint varchar(255);

3. Configure Sendy to trigger the Webhook

Once you’ve published the web app, configure a trigger in Sendy:

  1. Log on to Sendy.

  2. Organisation → Rules.

  3. Create a new rule → On Subscribe → (Pick a list) → Trigger Webhook.

  4. Paste in the URL to the Google Script (URL usually looks like:…/exec)

Now Sendy will invoke the webhook whenever there’s a new subscriber!

Script source code

Here are the three files that make up this script.

 * Adds a subscription 'event' into the spreadsheet.
function registerSubscriptionEvent(trigger, name, listName, sourceUrl) {
  // Add the data into the sheet
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheets()[0];

  var now = new Date();

    Utilities.formatDate(now, 'Etc/GMT', 'yyyy-MM-dd HH:mm:ss'),

function doPost(event) {

  // To invoke this function from Sendy,
  // 1. Add a new Custom Field to the list: "SourceURL"
  // 2. Rules > Create new rule > On Subscribe > Invoke Webhook > Paste URL to this script on

  Logger.log("Received post data: %s", event.postData?.contents);


    // Any other custom fields you have, e.g.:
    , event.parameter?.SourceURL

  return ContentService.createTextOutput('Thanks man');

function doGet() {
  return ContentService.createTextOutput('This service does not support GET. Bye!');

This is just a test harness that you can use:

function testDoPost() {
  var event = {
    postData: {
      contents: "trigger=subscribe&name=Horseface&"