Home
Connectors
Loop Subscriptions - Klaviyo

Send every Loop Subscriptions event to Klaviyo, server-side

Q: Which events does Klaviyo receive?

ViewContent as Viewed Product, AddToCart as Added to Cart, InitiateCheckout as Started Checkout and Purchase as Placed Order.

Q: Which customer parameters are sent to Klaviyo?

Upstack’s identity resolution attaches the visitor’s email before an event is forwarded, and syncs profile properties ($first_name, $last_name, $city, $region) plus custom identity properties to Klaviyo.

Q: How do I check that Loop Subscriptions events are reaching Klaviyo?

Upstack marks the destination Healthy, and Analytics, Metrics in Klaviyo shows Upstack events such as Added to Cart - Upstackified within a few minutes of live traffic. Then contact Upstack support to set up your Upstack abandonment flows.

Q: How long does it take to connect Loop Subscriptions to Klaviyo?

Most brands are live in under 20 minutes. Once Loop Subscriptions is connected, every destination receives the same resolved events, Klaviyo included.

Each event is resolved to a person against a 750M+ device graph before it reaches Klaviyo, so flows trigger on a known profile rather than an anonymous session.

Request a demo Start free trial

US device IDs in the graph: 750M+
Match rate on events: 90%+
Identity window, per customer: Lifetime
Most brands are live: <20 min

How it flows

How a Loop Subscriptions event reaches Klaviyo. Captured on the server, resolved to a person, then sent.

01 Capture

Captured from Loop Subscriptions

Capture Loop Subscriptions events server-side (new subscriptions, renewals, swaps and cancellations), each as what it actually is.

See the Loop Subscriptions integration

Loop SubscriptionsWhat it sends

subscription_idthe Loop subscription across its whole life
email / phonesubscriber contact
event_typerenewal, swap, skip, pause, cancel or save
line_itemsproducts after any swap
total / intervalcharge amount and billing cadence

02 Understand

Resolved to one person before it leaves

Every Loop Subscriptions event is matched against a 750M+ device graph, so a phone browse and a desktop checkout resolve to one customer rather than two strangers.

How resolution works

Resolved before it is sent

IdentityMatched against a 750M+ device graph, so a phone browse and a desktop checkout resolve to one customer.
customer_typeNew or returning, resolved before send.
DeduplicationOne order produces one event, so a single purchase cannot trigger the same flow twice.
Bot and fraud filteringAutomated traffic never becomes a profile, so list quality and deliverability are not paying for it.

Messaging mistakes are expensive and public. These controls exist so a flow never fires against a profile that should not have received it.

03 Activate

Delivered to Klaviyo

Attach re-identified emails to events before they reach Klaviyo, so browse and cart flows fire for people the pixel lost.

See the Klaviyo integration

KlaviyoWhat it receives

email / phonethe profile key: no profile, no send
external_idtie a browse to a known person
$valueflow and campaign revenue attribution
event propertieswhat the flow branches on

Which events reach Klaviyo

Each Upstack event is mapped to the Klaviyo event below before it is sent.

Upstack event	Sent to Klaviyo as	Key data on the event
Product view	Viewed Product	ProductName, ProductID, Price, ImageURL
Add to cart	Added to Cart	ProductName, ProductID, Price, Quantity, CartValue
Checkout	Started Checkout	CartValue, ItemCount, CheckoutURL
Purchase	Placed Order	OrderID, Revenue, Items, DiscountCodes

Upstack’s identity resolution attaches the visitor’s email before an event is forwarded, and syncs profile properties ($first_name, $last_name, $city, $region) plus custom identity properties to Klaviyo.

The catch

A save (a customer offered a discount instead of canceling) is the highest-signal retention event there is, and it is invisible to any flow triggered on orders alone.

Where to check in KlaviyoSending you can audit

Klaviyo Analytics Metrics

The event appears as its own metric, and the profile count on it is the number you were losing before.

What changes

What changes when Loop Subscriptions feeds Klaviyo. Two gains on the Klaviyo side, two on the Loop Subscriptions side.

Klaviyo

Recover carts you couldn’t email

Anonymous browsers are resolved to a known profile, so abandonment flows can trigger for visitors Klaviyo never identified.

Klaviyo

Profiles, not sessions

Events arrive attached to a resolved customer, so flow logic and segmentation work on a person.

Loop Subscriptions

Every event, server-side

Storefront and checkout events are captured from Loop Subscriptions on the server, independent of the browser.

Loop Subscriptions

One setup, every destination

Connect Loop Subscriptions once and forward to every ad platform, email tool and warehouse you run.

Setup

Live in under 20 minutes.

You need admin access to a Klaviyo account, with permission to create a Private API key with Full Access.

Upstack dashboardExample

Loop Subscriptions Data source Connected

Klaviyo Destination Healthy

Read the full Klaviyo setup guide

01

Connect Loop Subscriptions

Capture Loop Subscriptions events server-side (new subscriptions, renewals, swaps and cancellations), each as what it actually is.
02

Add the Klaviyo destination

Under Destinations, add Klaviyo with a Private API key named UpstackData, created with Full Access under Settings, Account, API Keys in Klaviyo. The key starts with pk_ and is shown only once.
03

Check metrics in Klaviyo

Upstack marks the destination Healthy, and Analytics, Metrics in Klaviyo shows Upstack events such as Added to Cart - Upstackified within a few minutes of live traffic. Then contact Upstack support to set up your Upstack abandonment flows.

FAQ

Questions about Loop Subscriptions and Klaviyo.

Which events does Klaviyo receive?

ViewContent as Viewed Product, AddToCart as Added to Cart, InitiateCheckout as Started Checkout and Purchase as Placed Order.

Which customer parameters are sent to Klaviyo?

How do I check that Loop Subscriptions events are reaching Klaviyo?

Upstack marks the destination Healthy, and Analytics, Metrics in Klaviyo shows Upstack events such as Added to Cart - Upstackified within a few minutes of live traffic. Then contact Upstack support to set up your Upstack abandonment flows.

How long does it take to connect Loop Subscriptions to Klaviyo?

Most brands are live in under 20 minutes. Once Loop Subscriptions is connected, every destination receives the same resolved events, Klaviyo included.