When a mailingListEntry.updated, mailingListEntry.abandoned, or mailingListEntry.removed event is triggered, FastSpring sends a webhook payload containing the customer's email address and any associated order details.

mailingListEntry.updated fires when a customer adds their email to your mailing list, or when the mailing list status changes (subscribed, unsubscribed, or abandoned).
mailingListEntry.abandoned fires 30 minutes after the most recent activity. This applies if a customer entered their email, but did not complete their purchase.
mailingListEntry.removed fires when a customer's email is removed from the mailing list. This may happen when a customer unsubscribes.

This page provides:

A full sample payload showing a populated mailingListEntry.updated, mailingListEntry.abandoned, and mailingListEntry.removed webhook
A detailed table listing every payload property, including name, type, and description
Notes on when this webhook is triggered

Webhook payload examples

mailingListEntry.updated

When a mailingListEntry.updated event is triggered, the webhook sends the following JSON payload:

{
    "id": "208cc47000a1c0b04991a742b151f7f84e04baee6ffbde7ecabd2911aee1d4ad",
    "list": "subscribed",
    "updated": 1751561132926,
    "reason": "subscribed",
    "order": {
        "reference": "ABC1234567-8910-11121D",
        "id": "abCdE1FGH2Hij3KLMnOpqR",
        "order": "abCdE1FGH2Hij3KLMnOpqR",
        "referrer": "https://mystore.test.onfastspring.com/cloud-storage",
        "session": "LDN5SX4KBZCI2:-WSh0LWdSn-delCV0a0ibw",
        "storefront": "mystore",
        "items": [
            {
                "product": "cloud-storage",
                "path": "cloud-storage",
                "quantity": 1,
                "display": "Cloud Storage Service",
                "summary": "Cloud Storage Service",
                "imageUrl": null,
                "isVirtual": false,
                "isSubscription": false,
                "price": 14.95,
                "variation": "cloud-storage",
                "description": "Cloud Storage Service",
                "sku": "SKU-12345",
                "pricing": {
                    "values": {
                        "USD": 14.95
                    }
                }
            }
        ]
    },
    "email": "[email protected]",
    "firstName": "Jane",
    "lastName": "Doe",
    "country": "US",
    "currency": "USD",
    "language": "en",
    "storefront": "mystore",
    "referrer": "https://mystore.test.onfastspring.com/cloud-storage",
    "optIn": false
}

mailingListEntry.abandoned

When a mailingListEntry.abandoned event is triggered, the webhook sends the following JSON payload:

{
    "id": "208cc47000a1c0b04991a742b151f7f84e04baee6ffbde7ecabd2911aee1d4ad",
    "list": "abandoned",
    "updated": 1751561434399,
    "reason": "abandoned",
    "order": {
        "reference": "ABC1234567-8910-11121D",
        "id": "abCdE1FGH2Hij3KLMnOpqR",
        "order": "abCdE1FGH2Hij3KLMnOpqR",
        "referrer": "https://app.fastspring.com/",
        "origin": "https://app.fastspring.com/2/product/home.xml?mRef=Product:XEBDgN...",
        "storefront": "mystore/popup-defaultB2B",
        "items": [
            {
                "product": "cloud-storage",
                "path": "cloud-storage",
                "quantity": 1,
                "display": "Cloud Storage Service",
                "summary": "Cloud Storage Service",
                "imageUrl": null,
                "isVirtual": false,
                "isSubscription": false,
                "price": 14.95,
                "variation": "cloud-storage",
                "description": "Cloud Storage Service",
                "sku": "SKU-12345",
                "pricing": {
                    "values": {
                        "USD": 14.95
                    }
                }
            }
        ]
    },
    "email": "[email protected]",
    "firstName": "Jane",
    "lastName": "Doe",
    "country": "US",
    "currency": "USD",
    "language": "en",
    "storefront": "mystore/popup-defaultB2B",
    "referrer": "https://app.fastspring.com/",
    "optIn": true
}

mailingListEntry.removed

When a mailingListEntry.removed event is triggered, the webhook sends the following JSON payload:

{
    "id": "208cc47000a1c0b04991a742b151f7f84e04baee6ffbde7ecabd2911aee1d4ad",
    "list": "unsubscribed",
    "updated": 1751561113784,
    "email": "[email protected]",
    "firstName": "Jane",
    "lastName": "Doe",
    "country": "US",
}

Payload properties

The payload properties table outlines each property in the mailingListEntry.subscribed, mailingListEntry.unsubscribed, and mailingListEntry.removed event JSON payload, specifying their name, data type, and description.

Name	Type	Description
id	string	Unique ID of this `mailingListEntry` event.
list	string	Updated list category: `subscribed`, `unsubscribed`, or `abandoned`.
updated	integer	Timestamp (in milliseconds) when this event was generated.
reason	string	Reason for the update: `subscribed`, `unsubscribed`, or `abandoned`.
order.reference	string	Customer-facing order reference number, or `null` if checkout was incomplete.
order.id	string	Unique order ID associated with this event.
order.order	string	Duplicate of `order.id` for backward compatibility.
order.referrer	string	URL of the page where the customer last came from before checkout or cart abandonment.
order.session	string	Session ID of the order at checkout. This expires after 24 hours.
order.origin	string	Original storefront (checkout) URL where checkout was initiated.
order.storefront	string	Name of the storefront (checkout) used.
order.items	array	Array of products that were in the cart when the customer entered their email. This array contains one object per product.
order.items.product	string	Product path or ID.
order.items.path	string	Same as `product`.
order.items.quantity	integer	Number of units the customer intended to purchase.
order.items.display	string	Customer-facing product name.
order.items.summary	string	Short description of the product.
order.items.imageUrl	string	URL of the product image, if any.
order.items.isVirtual	boolean	Indicates whether the product is virtual (non-physical). Always `false` for physical products.
order.items.isSubscription	boolean	Indicates whether the product is a subscription. Returns `true` if the product is a subscription.
order.items.price	number	Unit price of the product in transaction currency.
order.items.variation	string	Product variation ID, if applicable.
order.items.description	string	Detailed product description.
order.items.sku	string	Stock Keeping Unit (SKU) for inventory tracking.
order.items.pricing	object	Product price. May contain one string pairing for each currency.
email	string	Email address entered or updated.
firstName	string	Customer's first name, if provided.
lastName	string	Customer's last name, if provided.
country	string	Two-letter ISO country code of the customer.
currency	string	Three-letter ISO currency code for the cart.
language	string	Two-letter ISO language code used in checkout.
storefront	string	Storefront (checkout) identifier used.
referrer	string	Full URL of the page where the customer completed checkout or abandoned the cart.
optIn	boolean	Indicates whether the customer opted in to marketing or communications via the FastSpring checkout. Returns `true` if the customer opted in to marketing communications.

Cart abandonment tracking

When a customer enters their email but doesn't complete checkout, FastSpring marks the cart as abandoned and sends a mailingListEntry.updated webhook.

Customer flow:

Start timer: The moment an item is added to cart, a 30-minute countdown begins.
Abandon event: If the purchase isn't completed within 30 minutes, the cart is flagged as abandoned.
Webhook dispatch: Within 15 minutes of abandonment, FastSpring sends:
- Event: mailingListEntry.updated
- list: abandoned
- reason: abandoned

The webhook's items array contains one object per abandoned product, each with:

product: Product path or ID
quantity: Units selected
display: Customer-facing product name
summary: Short product description
imageUrl: URL of the product's icon image

Customer mailing list opt-in (subscribed)

When checking out, customers can select a checkbox to opt-in to future emails:

When a customer completes a purchase with a new email address, FastSpring sends their email in the mailingListEntry.updated webhook.
If the customer opted in to future emails, FastSpring marks the list and reason properties as subscribed.

This fires once per unique email; repeat opt-ins with the same email address are ignored.

Customer mailing list opt-out (unsubscribed)

If a subscribed customer opts out of the mailing list, FastSpring sends two webhook events in the following order:

mailingListEntry.removed: Shows the list property as subscribed. FastSpring will remove the email address from the mailing list.
mailingListEntry.updated: Shows the list and the reason properties as unsubscribed.

Note:
For third-party remarketing services, see Extensions. These services help you receive webhook data, parse the information, and send remarketing messages to consumers with abandoned carts.