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INTEGRATION / KLAVIYO

Klaviyo Custom API Integration

Send the customer, catalog and behavioral data your marketing flows actually need—even when the native connector cannot support the workflow.


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Built by developers experienced with WooCommerce APIs, webhooks and custom data workflows.

When the native connector is not enough.

  • The event the marketing team needs is not tracked by the standard integration.
  • Data arrives in Klaviyo too late to trigger time-sensitive flows.
  • Customer profile properties are incomplete or inconsistent.
  • The business needs data from an ERP, CRM or warehouse in Klaviyo segments.
  • Events are duplicated, inflating metrics and breaking triggers.
  • Browser-side tracking is blocked, so server-side event delivery is required.
  • The marketing team cannot build the segments it needs because the payload is too limited.

What we build.

  • Custom event tracking
  • Customer profile synchronization
  • Catalog and product data synchronization
  • Subscription and consent handling
  • Server-side event delivery
  • WooCommerce and Shopify data mapping
  • Custom properties for segmentation
  • Webhook receivers
  • Retry handling and deduplication
  • Historical data migration
  • Monitoring and troubleshooting

Reliable event delivery from any source.

We connect store, backend and third-party data to Klaviyo through server-side API calls and webhook receivers, with retries, deduplication and logging built in from the start.

  • Event taxonomy designed with the marketing team before development.
  • Server-side API delivery for events that cannot be tracked in the browser.
  • Profile enrichment from ERP, CRM, warehouse or custom databases.
  • Idempotent event keys prevent duplicates during retries.
  • Webhook endpoints receive updates from Klaviyo and external systems.
  • Retry queues and backoff handle Klaviyo rate limits and outages.
  • Structured logging lets the team trace any event from source to Klaviyo.
  • Monitoring alerts when event volumes or error rates change unexpectedly.

What you get.

  1. Discovery: audit of current events, profile properties and segmentation needs.
  2. Event and property mapping document aligned with marketing goals.
  3. Implementation: custom API integration, webhooks and enrichment logic.
  4. Testing: sample events, edge cases, consent handling and failure scenarios.
  5. Deployment: staged release with real-time monitoring.
  6. Documentation: event dictionary, runbook and troubleshooting guide.
  7. Monitoring: event logs, retry status and data-quality alerts.
  8. Handover: training and support for the marketing and operations teams.

How we work.

  1. Discovery and data mapping

    We review current Klaviyo setup, identify missing events and properties, and design the event taxonomy with the marketing team.

  2. Technical plan

    We choose API or webhook direction, define deduplication keys, retry rules and data sources for profile enrichment.

  3. Implementation and testing

    We build the integration in staging, send sample events and validate counts, timing and segmentation in Klaviyo.

  4. Deployment and monitoring

    We release to production, monitor event flow and quality, and keep logs active during the first campaigns.

FAQ

Questions about this service

When is a custom Klaviyo API integration necessary?

A custom integration is needed when the native connector misses events, sends incomplete profile properties, delays data, duplicates events, or cannot reach data stored in an ERP, CRM or custom database.

Which custom events can be sent to Klaviyo?

Any event that can be captured in your store or backend can be sent: custom checkout steps, B2B account actions, subscription changes, loyalty events, product usage, back-in-stock triggers and more.

Can Klaviyo connect to an ERP or CRM?

Yes. We can enrich Klaviyo profiles and events with data from ERPs, CRMs, warehouses or custom systems, then send that data server-side through the Klaviyo API or receive Klaviyo webhooks.

How do you prevent duplicate events?

We use event IDs, deduplication keys and idempotent API calls. Events are logged so the marketing team can verify counts and investigate discrepancies without relying on guesses.

Can historical customer and event data be imported?

Yes. Historical profiles, orders and events can be backfilled in batches, respecting Klaviyo rate limits. We validate the data before import and reconcile counts afterward.

How do you troubleshoot delayed or missing Klaviyo events?

We add structured logging, event timestamps and retry queues. When an event is missing, we can trace it from the source system through the integration to Klaviyo and identify whether the issue is timing, filtering, authentication or payload format.

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