Custom stack to Klaviyo
Forward every Custom stack event to Klaviyo server-side, resolved to a person against a 750M+ device graph — so flows trigger on a known profile rather than an anonymous session.
Connection
Connect Custom stack to Klaviyo with Upstack Data
Custom stack
Not on the list? Send events to Upstack from any stack over webhook or direct post, with the same schema and the same resolution.
Custom stack integrationKlaviyo
Attach re-identified emails to events before they reach Klaviyo, so browse and cart flows fire for people the pixel lost.
Klaviyo integrationWhat changes
What changes when Custom stack feeds 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.
Profiles, not sessions
Events arrive attached to a resolved customer, so flow logic and segmentation work on a person.
Any stack, any framework
Headless, custom checkout, native app or a platform we haven’t listed — if it can make an HTTP request, it can send to Upstack.
The same event schema
Custom events are resolved, filtered and forwarded exactly like a Shopify order.
What actually moves
What Custom stack carries, and what Klaviyo needs.
Custom stack and Klaviyo describe a customer with different vocabularies. This is the mapping Upstack applies on the way through — the left column is what Custom stack can put on an event, the right is what Klaviyo can actually use.
Custom stack sends
- event_name
- whatever you choose to call it
- user identifiers
- any of email, phone, external ID
- value / currency
- if the event carries revenue
- custom properties
- any attribute in your own schema
Klaviyo receives
- email / phone
- the profile key — no profile, no send
- external_id
- tie a browse to a known person
- $value
- flow and campaign revenue attribution
- event properties
- what the flow branches on
Sending you can audit
How you know it is working.
Messaging mistakes are expensive and public. These controls exist so a flow never fires against a profile that should not have received it.
Per-profile inspection
Trace any event to the profile it resolved to, and see why.Deduplication
One order produces one event, so a single purchase cannot trigger the same flow twice.Bot and fraud filtering
Automated traffic never becomes a profile, so list quality and deliverability are not paying for it.
Where to check in Klaviyo
KlaviyoAnalyticsMetrics. The event appears as its own metric, and the profile count on it is the number you were losing before.
Related connectors
Other places Custom stack can send to.
- Custom stackMeta Conversions API
- Custom stackGoogle Ads Conversions
- Custom stackTikTok Events API
- Custom stackPinterest
- Custom stackSnapchat
- Custom stackReddit
- Custom stackMicrosoft Ads
- Custom stackX
Other sources that feed Klaviyo.
- ShopifyKlaviyo
- WooCommerceKlaviyo
- BigCommerceKlaviyo
- Checkout ChampKlaviyo
- RechargeKlaviyo
- FunnelishKlaviyo
- Lasso CommerceKlaviyo
- Phoenix TechnologiesKlaviyo
- SkioKlaviyo
- Loop SubscriptionsKlaviyo
- StripeKlaviyo
- Everything Klaviyo can take12 sources feed Klaviyo, and the setup is the same for each one.Klaviyo integration
- How resolution worksEvery event matched against a 750M+ device graph before it is forwarded.Upstack Signal
- What it costsThree plans that scale with your order volume. Every connector is on every plan.See pricing
Get Custom stack talking to Klaviyo.
A 15-minute walkthrough of this connector on your own account.