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": "jane.doe@company.com",
    "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": "jane.doe@company.com",
    "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": "jane.doe@company.com",
    "firstName": "Jane",
    "lastName": "Doe",
    "country": "US",
}

Navigate this webhook

The mailingListEntry.updated, mailingListEntry.abandoned, and mailingListEntry.removed webhook payloads all share the same structure, with minor differences depending on the event type. Use the cards below to jump to a specific section of the property reference.

Event Fields

Order Summary

Order Items

Payload properties

All fields below are included in the mailingListEntry.updated, mailingListEntry.abandoned, or mailingListEntry.removed webhook payloads. Fields are grouped into categories for easier navigation.

Name	Type	Description
Event Fields
id	string	Unique ID of this `mailingListEntry` event
list	string	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`
email	string	Email address entered or updated
firstName	string	Customer first name, when provided
lastName	string	Customer last name, when provided
country	string	Two-letter ISO country code
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 where the customer came from before checkout or abandonment
optIn	boolean	Whether the customer opted in to communications via checkout
Order Summary
order.reference	string	Customer-facing order reference (may be `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 the customer visited immediately before checkout/cart
order.session	string	Checkout session ID (expires after 24 hours)
order.origin	string	Original storefront URL where checkout was initiated
order.storefront	string	Storefront name/path used for the session
Order Items
order.items	array	Products in the cart when the email was captured
order.items.product	string	Product path or ID
order.items.path	string	Duplicate of `order.items.product`
order.items.quantity	integer	Units the customer intended to purchase
order.items.display	string	Customer-facing product name
order.items.summary	string	Short product description
order.items.imageUrl	string	Product image URL, when available
order.items.isVirtual	boolean	Whether the product is virtual (non-physical)
order.items.isSubscription	boolean	Whether the product is a subscription
order.items.price	number	Unit price in transaction currency
order.items.variation	string	Product variation ID, when applicable
order.items.description	string	Detailed product description
order.items.sku	string	Stock Keeping Unit (SKU)
order.items.pricing	object	Price map by currency (e.g., `values.USD`)

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