Real-time
Two-way sync
Changes in Customer.io or Folk CRM instantly reflect in both systems. No stale data, no manual imports.
Business productivity ⇄ CRM
Customer.io to Folk CRM integration — real-time, two-way sync
Keep Customer.io and Folk CRM 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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Migrated from MuleSoft
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Migrated from Celigo
Migrated from Heroku Connect
Migrated from Matillion
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Migrated from Fivetran
Case study
Migrated from Celigo
Why teams connect Customer.io and Folk CRM
Sync what happens in Customer.io with the customer records in Folk CRM, 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 Customer.io 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 Campaigns, Broadcasts, Deliveries / Messages, Newsletters in Customer.io to Notes, Reminders, People, Companies in Folk CRM with bi-directional, real-time sync. Activity and record changes in Customer.io update the matching contact or account in Folk CRM, and CRM data flows the other way wherever Customer.io can store and use it.
Common use cases
- 01 Keep unsubscribe and subscription-preference state consistent between Customer.io and the CRM to avoid compliance gaps.
- 02 Sync account-level objects and their person relationships for B2B messaging keyed to company attributes.
- 03 Push enriched contact data from a data warehouse into folk custom fields.
- 04 Mirror folk groups into a reporting database to track pipeline and outreach coverage.
Common sync patterns
Where Customer.io supplies contact or company data
Enriched fields land directly on records in Folk CRM, and refreshes keep them from going stale.
Where Customer.io processes payments
Charges, refunds, and subscription changes appear on the account in Folk CRM, so revenue context lives with the relationship.
Where Customer.io can store CRM context: fields kept current
Owner, lifecycle stage, or account details from Folk CRM sync into Customer.io, so people working there have the context without switching tools.
What you can sync between Customer.io and Folk CRM
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.
| Customer.io objects | Folk CRM objects | How this pairing syncs | |
|---|---|---|---|
| People Profiles with attributes, matched on identifiers like id or email; the main write target of data syncs. | People Contact records; the primary entity synced with outreach and enrichment tools. | Same entity on both sides — records pair one-to-one and field-level changes reconcile in both directions. | |
| Objects Non-person entities such as accounts or companies, related to people for account-level messaging. | Companies Organization records linked to people and kept aligned with billing or CS systems. | Objects is specific to Customer.io and Companies to Folk CRM — each maps to any object or custom field on the other side. | |
| Events Behavioral events sent via the Track API that trigger campaigns. | Groups Shared workspaces that organize contacts; group membership is often the field integrations act on. | Events is specific to Customer.io and Groups to Folk CRM — each maps to any object or custom field on the other side. | |
| Segments Attribute- or event-based groups; data syncs feed the attributes segments evaluate. | Custom fields Group-scoped attributes that receive enriched or computed values from external systems. | Segments is specific to Customer.io and Custom fields to Folk CRM — each maps to any object or custom field on the other side. | |
| Campaigns Automated workflows whose membership and metrics can be read via the App API. | Notes Free-text context attached to people and companies, readable for reporting. | Campaigns is specific to Customer.io and Notes to Folk CRM — each maps to any object or custom field on the other side. | |
| Broadcasts One-off sends to segments or audiences, triggerable via API. | Reminders Follow-up items that can be created from external triggers. | Broadcasts is specific to Customer.io and Reminders to Folk CRM — each maps to any object or custom field on the other side. |
How changes propagate between Customer.io and Folk CRM
Each direction of the sync is driven by what the source system can signal and what the destination accepts — detection, delivery, and expected latency below.
Customer.io Folk CRM Sub-second propagation
DetectionCustomer.io notifies Stacksync of record changes through webhook events. Reporting webhooks push message and delivery events.
DeliveryEach detected change is written to Folk CRM through its API, with automatic retries and rate-limit backoff.
Folk CRM Customer.io Sub-second propagation
DetectionFolk CRM notifies Stacksync of record changes through webhook events. Webhook subscriptions for record events, with polling of list endpoints as a fallback.
DeliveryEach detected change is written to Customer.io through its API, with automatic retries and rate-limit backoff.
Rate-limit considerations
- Customer.io: Subject to per-API rate limits documented by Customer.io.
- Folk CRM: Subject to the platform's API rate limits.
What ships with Customer.io ⇄ Folk CRM
Connect Customer.io and Folk CRM for flexible, real-time data sync.
Real-time sync, workflow automation, event queues, EDI, and monitoring, for every Customer.io–Folk CRM connection.
No-code + pro-code
Workflow automation
Trigger automated workflows whenever Customer.io or Folk CRM 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 or Folk CRM record.
Observability
Monitoring
Track your Customer.io ⇄ Folk CRM sync health, view errors, and replay failed events in one click.
Trading partners
EDI
Transform legacy EDI complexity into simple database interactions between Customer.io and Folk CRM.
How the Customer.io and Folk CRM connectors work
Customer.io
- Integration surface
- 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
- Capabilities
- read · write · webhooks
- Rate limits
- Subject to per-API rate limits documented by Customer.io
Folk CRM
- Integration surface
- REST API
- Authentication
- API key (Bearer token)
- Change detection
- Webhook subscriptions for record events, with polling of list endpoints as a fallback
- Capabilities
- read · write · webhooks
- Rate limits
- Subject to the platform's API rate limits
How it works
How to connect Customer.io to Folk CRM — 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.
- 01
Connect your apps
Authenticate Customer.io and Folk CRM with each platform's native method — OAuth, API keys, or service accounts — plus secure options like SSH tunneling, IP whitelisting, and VPC peering.
Customer.io
connected
Folk CRM
connected
OAuth 2.0SSH tunnelSSL certificateVPC peering - 02
Choose tables
Pick the Customer.io and Folk CRM 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.
objects · Customer.io ⇄ Folk CRMCustomers 12,480Sales Orders 8,213Invoices 5,902Items 1,344 - 03
Map fields
Fields map automatically even when names and types differ. Stacksync handles transformation and type casting for you, zero configuration required.
Customer.io Folk CRMCompany company_name textEmail email textAmount amount numericCreated created_at timestamp
FAQ
Customer.io and Folk CRM integration FAQ
-
Yes. Stacksync provides a managed, real-time two-way integration between Customer.io and Folk CRM: authenticate both systems, choose the objects to sync (such as Customer.io's People and Objects), map fields visually, and changes propagate both ways in milliseconds — no code required.
-
Stacksync is SOC 2 Type II and ISO 27001 certified with HIPAA BAA support. Data is encrypted in transit, and a zero-persistent-storage architecture means Customer.io and Folk CRM records are not retained after a sync operation.
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Stacksync pricing is usage-based and starts at $1,000/month, including the managed Customer.io and Folk CRM connectors, real-time two-way sync, monitoring, and support. That replaces building and maintaining a custom Customer.io–Folk CRM integration in-house.
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Yes — Stacksync ships production-grade connectors for both Customer.io and Folk CRM. The connectors handle authentication, schema detection, rate limits, and retries; you configure the sync, and Stacksync operates it.
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Change detection on Customer.io: Reporting webhooks push message and delivery events; person attribute changes are not streamed and require source-side detection. On Folk CRM: Webhook subscriptions for record events, with polling of list endpoints as a fallback. Each detected change propagates to the other side in milliseconds, with field-level conflict resolution and an inspectable event log.
-
On the Customer.io side: Campaigns, Broadcasts, Deliveries / Messages, Newsletters, plus custom fields where Customer.io exposes them. On the Folk CRM side: Notes, Reminders, People, Companies. Stacksync auto-detects both schemas and converts types between the two systems.
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.
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:
Related integrations
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