Webhooks allow you to subscribe to real-time notifications about various events that occur in MailerLite. For example, when a new subscriber is added to your account, HTTP POST callback is sent to your provided URL with a payload containing the new subscriber. It allows you to get the most recent updates without constantly polling the API.


Currently, you can only create subscriptions using our RESTful API for webhooks. It is documented here.


Our responses contain fat payloads including the information about the event-related object so there is no need to make an additional API request.

  "events": [
        "account_id": 334443,
        "data": {
          "subscriber": {
            "clicked": 0,
            "date_created": "2017-05-23 14:50:03",
            "date_subscribe": null,
            "date_unsubscribe": null,
            "date_updated": null,
            "email": "[email protected]",
            "fields": [
                "value":"[email protected]",
            "id": 2300951083,
            "name": "Guy",
            "opened": 0,
            "sent": 0,
            "type": "active"
        "timestamp": 1495551003,
        "type": "subscriber.create",
        "webhook_id": 2

Available events

subscriber.createFired when a new subscriber is added to an account.
subscriber.activeFired when an unconfirmed subscriber confirms their subscription.
subscriber.updateFired when any of the subscriber's custom fields are updated.
subscriber.unsubscribeFired when a subscriber becomes unsubscribed.
subscriber.add_to_groupFired when a subscriber is added to a group.
subscriber.remove_from_groupFired when a subscriber is removed from a group.
subscriber.added_through_webformFired when a subscriber is added though a form.
subscriber.bouncedFired when an email address bounces.
subscriber.complaintFired when subscriber marks a campaign as a spam.
subscriber.automation_triggeredFired when subscriber starts automation.
subscriber.automation_completeFired when subscriber finishes automation.
campaign.sentFired when campaign is sent.

Batching events

We send events in batches every minute. For example, if there are a few events fired and they belong to the same webhook, we group all of them and send a single HTTP request instead of multiple requests to the same URL.


Webhook requests include X-MailerLite-Signature header, its value is base64 encoded HMAC (sha256) which is generated from payload JSON using your account's API key as a secret key. You can check its validity in order to be guaranteed that a request is sent from our side.

An example of a working function which produces a signature in PHP:


function generateSignature($jsonPayload, $apiKey) {
  return base64_encode(
    hash_hmac('sha256', $jsonPayload, $apiKey, true)


If there is any other response than 2xx from your webhook's endpoint, we attempt to retry our callbacks for a while. However, your webhook is set to inactive after 3 days of responding with an error.

Unsubscribing webhooks

You can manually stop subscribing events for a particular webhook by using API or just responding with a status code 410.

Useful tools

Requestbin is a useful tool for testing webhooks quickly and seeing how it works without any coding on your side to see what's being sent.