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Business productivity

Connect Customer.io to any app with two-way sync.

Two-way sync Customer.io across all your CRMs, databases, data warehouses, EDI systems, and AI tools, with custom workflows tailored to your data.

  • 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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Migrated from MuleSoft
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Object catalog

What Stacksync syncs in Customer.io.

These objects sync between Customer.io and any connected system, with field-level mapping and conflict resolution. Custom fields are picked up from the live schema where Customer.io exposes them.

People
Profiles with attributes, matched on identifiers like id or email; the main write target of data syncs.
Objects
Non-person entities such as accounts or companies, related to people for account-level messaging.
Events
Behavioral events sent via the Track API that trigger campaigns.
Segments
Attribute- or event-based groups; data syncs feed the attributes segments evaluate.
Campaigns
Automated workflows whose membership and metrics can be read via the App API.
Broadcasts
One-off sends to segments or audiences, triggerable via API.
Deliveries / Messages
Per-recipient message records whose lifecycle events flow out through reporting webhooks.
Newsletters
Recurring email sends with performance metrics available for reporting syncs.
API surface

How Stacksync connects to Customer.io.

The connector runs on Customer.io's native API. Stacksync manages authentication, rate limits, retries, and schema changes so your team does not maintain integration code.

Connection
REST APIs split by purpose: Track API for data ingestion, App API for campaigns, people lookups, and messages
Authentication
Basic auth with site ID and API key for the Track API; bearer token for the App API
Change detection
Reporting webhooks push message and delivery events; person attribute changes are not streamed and require source-side detection
Rate limits
Subject to per-API rate limits documented by Customer.io

Sync directions

  • Read Supported
  • Write Supported
  • Change data capture Not available
  • Webhooks Supported
What ships with Customer.io

Connect Customer.io for flexible, real-time data sync.

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

Real-time

Two-way sync

Changes in Customer.io instantly reflect across connected systems. No stale data, no manual imports.

No-code + pro-code

Workflow automation

Trigger automated workflows whenever Customer.io 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 Customer.io record.

Observability

Monitoring

Track your Customer.io sync health, view errors, and replay failed events in one click.

Trading partners

EDI

Transform legacy EDI complexity into simple database interactions.

Use cases

What teams run on the Customer.io connector.

Customer.io is bought by lifecycle and marketing ops teams, often paired with growth engineering, at product companies that run automated email, SMS, and push messaging off first-party data. It sits downstream of the product database and CRM as the messaging layer: People profiles, Events, Segments, and delivery history accumulate there, and campaign engagement data is valuable back upstream for attribution.

  • Lifecycle/marketing ops
  • Growth engineering
  • Data engineering
  • RevOps

  1. Sync product usage and billing attributes from Postgres onto Customer.io people so lifecycle campaigns trigger on real product behavior.

  2. Push CRM segments and lead status into Customer.io so messaging respects sales stage.

  3. Land delivery and engagement events (sent, opened, clicked, bounced) from reporting webhooks into a warehouse for attribution analysis.

  4. Keep unsubscribe and subscription-preference state consistent between Customer.io and the CRM to avoid compliance gaps.

  5. Sync account-level objects and their person relationships for B2B messaging keyed to company attributes.

  6. Sync People and their attributes from a production Postgres or warehouse into Customer.io so Segments and Campaigns always run on current product data instead of stale CSV imports.

All Customer.io integrations

Pick the system you need to keep in sync with Customer.io. Each page covers the sync setup, field mapping, and common workflows for that pair.

CRM · 33

ERP · 24

Database · 18

Data warehouse · 10

Business productivity · 30

Accounting and finance · 16

How it works

Set up Customer.io in minutes, without APIs.

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 Customer.io with its 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
    Customer.io connected
    OAuth 2.0
    SSH tunnel
    SSL certificate
    VPC peering
  2. 02

    Choose tables

    Pick the Customer.io objects to sync — Stacksync auto-detects the schema, 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 · Customer.io
    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
    Customer.io database
    Company company_name text
    Email email text
    Amount amount numeric
    Created created_at timestamp
Try interactive demo

FAQ

Customer.io connector FAQ

What can I sync with the Customer.io connector?

Customer.io's core objects — People, Objects, Events, Segments and custom fields — can sync with any of 302 other systems. Every integration is real-time and bidirectional, with field-level mapping and conflict resolution.

How does Stacksync connect to Customer.io?

Via REST APIs split by purpose: Track API for data ingestion, App API for campaigns, people lookups, and messages, authenticated with Basic auth with site ID and API key for the Track API; bearer token for the App API. Changes are detected as follows — reporting webhooks push message and delivery events; person attribute changes are not streamed and require source-side detection. Stacksync manages rate limits, retries, and schema changes automatically.

Is the Customer.io connector two-way?

Yes. Changes made in Customer.io propagate to the connected system and vice versa, in milliseconds. One-way flows are also supported when a direction should stay read-only.

How long does a Customer.io integration take to set up?

Most Customer.io integrations go live in minutes: authenticate Customer.io and the other system, pick objects and fields, and enable the sync. No code and no infrastructure to manage.

Is Customer.io data secure in transit?

Stacksync is SOC 2 Type II, ISO 27001, GDPR and HIPAA compliant. Customer.io data is encrypted in transit, and a zero-persistent-storage architecture means records are not retained after a sync operation.

SECURITY

Security teams trust 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
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
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