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Business productivity ⇄ CRM

Klaviyo to Kustomer integration — real-time, two-way sync

Keep Klaviyo and Kustomer in sync without custom scripts. Cut weeks of integration work, eliminate silent data drift, and give your team a single, reliable source of truth.

  • SOC 2 and 6 other compliance frameworks
  • POC with real engineers in minutes

Adopted by fast-scaling companies moving mission-critical data in real time

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Why teams connect Klaviyo and Kustomer

Sync what happens in Klaviyo with the customer records in Kustomer, in real time and in both directions.

The CRM is supposed to be the record of every customer relationship, but customer-relevant information also accumulates in the other tools a team runs. Whatever Klaviyo holds or produces that touches a customer, whether conversations, payments, replies, enriched data, or notes, the CRM only benefits if it arrives without someone copying it over.

Stacksync connects Tags, Profiles, Lists, Segments in Klaviyo to Custom Objects (Klasses), Users, Teams, Tags in Kustomer with bi-directional, real-time sync. Activity and record changes in Klaviyo update the matching contact or account in Kustomer, and CRM data flows the other way wherever Klaviyo can store and use it.

Common use cases

  • Sync catalog items from an ERP or PIM so product recommendations and back-in-stock flows use current data
  • Sync customer profiles between Klaviyo and the CRM or warehouse so segments can use fields beyond storefront data
  • Escalate conversation-derived signals into the CRM as tasks or opportunities
  • Sync customers bi-directionally with the CRM and ERP so agents see deal, billing, and subscription context on the timeline

Where Klaviyo processes payments

Charges, refunds, and subscription changes appear on the account in Kustomer, so revenue context lives with the relationship.

Where Klaviyo can store CRM context: fields kept current

Owner, lifecycle stage, or account details from Kustomer sync into Klaviyo, so people working there have the context without switching tools.

Where Klaviyo runs outreach

Prospects, sends, and replies sync into Kustomer, keeping lead status current without manual imports.

What you can sync between Klaviyo and Kustomer

Representative objects on each side — any object or custom field can map to any target. Schemas are auto-detected; types are converted between the two systems.

Klaviyo objects Kustomer objects
Tags Organizational labels on campaigns, flows, and lists support reporting rollups. Conversations Support threads across channels sync outward for analytics and CRM context.
Profiles Person records with arbitrary custom properties are the target for CRM and warehouse-sourced attributes. Messages Individual messages within conversations support full-thread replication.
Lists Static audience memberships sync in from CRMs and forms for targeting. Companies Organization records group customers and map to CRM accounts.
Segments Dynamic audiences are readable so other tools can mirror who qualifies. Custom Objects (Klasses) Structured external records such as orders and subscriptions synced in to appear on the customer timeline.
Events Timestamped behavioral records tied to metrics; external order and product events are pushed in to trigger flows. Users Agent records map conversation ownership to people in other systems.
Metrics Event type definitions organize the activity stream used in segmentation and attribution. Teams Team assignments support routing parity and reporting.
What ships with Klaviyo ⇄ Kustomer

Connect Klaviyo and Kustomer for flexible, real-time data sync.

Real-time sync, workflow automation, event queues, EDI, and monitoring, for every Klaviyo–Kustomer connection.

Real-time

Two-way sync

Changes in Klaviyo or Kustomer instantly reflect in both systems. No stale data, no manual imports.

No-code + pro-code

Workflow automation

Trigger automated workflows whenever Klaviyo or Kustomer data changes, update records, fire webhooks, or kick off sequences without brittle API scripts.

At scale

Event queues

Handle millions of events per minute without losing a single Klaviyo or Kustomer record.

Observability

Monitoring

Track your Klaviyo ⇄ Kustomer sync health, view errors, and replay failed events in one click.

Trading partners

EDI

Transform legacy EDI complexity into simple database interactions between Klaviyo and Kustomer.

How the Klaviyo and Kustomer connectors work

Klaviyo

Integration surface
REST API compliant with the JSON:API specification
Authentication
OAuth 2.0 for apps or private API keys
Change detection
Polling on updated timestamps; outbound webhooks exist for event topics (availability depends on plan or app-partner status) and as flow webhook actions
Capabilities
read · write · webhooks
Rate limits
Per-endpoint burst and steady rate limits apply

Kustomer

Integration surface
REST API
Authentication
API key used as a bearer token, scoped by role
Change detection
Outbound webhooks on record events, plus polling for backfill
Capabilities
read · write · webhooks
Rate limits
Subject to the platform's API rate limits
How it works

How to connect Klaviyo to Kustomer — three steps, no code

Configure and sync within minutes, no code. Whether you sync 50k or 100M+ records, Stacksync handles the queues, infra, and plumbing. Integrations are non-invasive and need zero setup on your systems.

  1. 01

    Connect your apps

    Authenticate Klaviyo and Kustomer with each platform's native method — OAuth, API keys, or service accounts — plus secure options like SSH tunneling, IP whitelisting, and VPC peering.

    • OAuth 2.0
    • SSH tunnel
    • VPC peering
    Klaviyo connected
    Kustomer connected
    OAuth 2.0
    SSH tunnel
    SSL certificate
    VPC peering
  2. 02

    Choose tables

    Pick the Klaviyo and Kustomer objects to sync — Stacksync auto-detects both schemas, including custom fields where the platform exposes them. Sync to existing tables, or let Stacksync create new ones with ideal data types.

    • Standard objects
    • Custom objects
    • Auto-schema
    objects · Klaviyo ⇄ Kustomer
    Customers 12,480
    Sales Orders 8,213
    Invoices 5,902
    Items 1,344
  3. 03

    Map fields

    Fields map automatically even when names and types differ. Stacksync handles transformation and type casting for you, zero configuration required.

    • Auto-map
    • Type casting
    • Transforms
    Klaviyo Kustomer
    Company company_name text
    Email email text
    Amount amount numeric
    Created created_at timestamp
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FAQ

Klaviyo and Kustomer integration FAQ

SECURITY

Security teams love Stacksync

As a data company, we understand the importance of keeping your data secure. Stacksync is built with security best practices to keep your data safe at every layer, and is DPF-certified for US, EU, UK and CH data transfers.

Learn more about security
SOC 2 type II
ISO 27001
HIPAA BAA
GDPR
CCPA
CSA STAR
DPF US-EU-UK-CH
→ SECURITY WITH BENEFITS

SSO & SCIM

Let your users access Stacksync from your centralized user management systems. Works with Okta, Azure, Google SSO and more.

Alerts

Immediately get alerted about record syncing issues over email, Slack, PagerDuty and WhatsApp. Resolve issues from a centralized dashboard with retry and revert options.

Secure connection options

Securely connects to your systems with:

OAuth 2 SSH Tunnelling SSL certificates IP Whitelisting VPN gateway VPC peering and more

Related integrations

Every pair below is a real-time, two-way sync. Search all 386 integrations available for Klaviyo and Kustomer.

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