Klaviyo Webhook Setup Guide

Delivery, engagement, and consent changes for email.

• Email Delivered (event:klaviyo.received_email) — fires when an email is delivered to a recipient.
• Opened Email (event:klaviyo.opened_email) — fires when a recipient opens an email.
• Clicked Email (event:klaviyo.clicked_email) — fires when a recipient clicks a link in an email.
• Bounced Email (event:klaviyo.bounced_email) — fires when an email soft or hard bounced.
• Dropped Email (event:klaviyo.dropped_email) — fires when a discrepancy occurs between the Klaviyo suppression status and the upstream email service provider, and the send is dropped.
• Marked Email as Spam (event:klaviyo.marked_email_as_spam) — fires when a recipient marks an email as spam.
• Subscribed to Email Marketing (event:klaviyo.subscribed_to_email_marketing) — fires when a profile consents to email marketing.
• Unsubscribed from Email Marketing (event:klaviyo.unsubscribed_from_email_marketing) — fires when a profile unsubscribes from email marketing.
• Manually Suppressed from Email Marketing (event:klaviyo.manually_suppressed_from_email_marketing) — fires when a profile is manually suppressed from email marketing.
• Manually Unsuppressed from Email Marketing (event:klaviyo.manually_unsuppressed_from_email_marketing) — fires when a profile is manually unsuppressed from email marketing.
• Updated Email Preferences (event:klaviyo.updated_email_preferences) — fires when a profile updates its preferences through the Manage Preferences link.

Delivery, engagement, and consent changes for SMS.

• Sent SMS (event:klaviyo.sent_sms) — fires when a recipient sends an inbound SMS to one of your Klaviyo sending numbers.
• Received SMS (event:klaviyo.received_sms) — fires when Klaviyo records that a recipient received an SMS message.
• Clicked SMS (event:klaviyo.clicked_sms) — fires when a recipient clicks a link within an SMS message.
• Failed to Deliver SMS (event:klaviyo.failed_to_deliver_sms) — fires when an SMS message is sent but not delivered to the recipient.
• Received Automated Response SMS (event:klaviyo.received_automated_response_sms) — fires when a recipient receives an automated SMS response to a keyword or auto-responder.
• Failed to Deliver Automated Response SMS (event:klaviyo.failed_to_deliver_automated_response_sms) — fires when an automated SMS response fails to be delivered to the recipient.
• Subscribed to SMS Marketing (event:klaviyo.subscribed_to_sms_marketing) — fires when a profile consents to SMS marketing.
• Unsubscribed from SMS Marketing (event:klaviyo.unsubscribed_from_sms_marketing) — fires when a profile unsubscribes from SMS marketing.

Delivery and engagement for mobile push notifications.

• Received Push (event:klaviyo.received_push) — fires when a recipient receives a push notification from a flow or campaign.
• Opened Push (event:klaviyo.opened_push) — fires when a recipient taps a push notification and opens the app.
• Bounced Push (event:klaviyo.bounced_push) — fires when a push notification is sent but not delivered.

Product review and rating activity.

• Ready to Review (event:klaviyo.ready_to_review) — fires when a product becomes available for review after fulfillment.
• Submitted Review (event:klaviyo.submitted_review) — fires when a product review is submitted with content and a rating.
• Submitted Rating (event:klaviyo.submitted_rating) — fires when a product rating is submitted.

How Klaviyo delivers these events to StackOne.

• Klaviyo batches events: a single delivery can carry up to 1,000 events, and StackOne processes each one separately.
• A batch can mix topics — every event carries its own topic, so events of different types can arrive together.
• Deliveries are signed with HMAC-SHA-256 in the Klaviyo-Signature header using a secret StackOne registers automatically — no manual verification is needed.
• The event payload mirrors Klaviyo’s Get Event response, so the metric detail available on an event is the same detail the Events API returns for it.