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Business productivity ⇄ CRM

Customer.io to Nutshell integration — real-time, two-way sync

Keep Customer.io and Nutshell 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

Case study
Migrated from Mulesoft
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Migrated from Celigo
Migrated from Heroku Connect
Migrated from Matillion
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Migrated from Fivetran
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Migrated from Celigo
Why teams connect Customer.io and Nutshell

Sync what happens in Customer.io with the customer records in Nutshell, 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 People, Objects, Events, Segments in Customer.io to Tags, Users, Leads, People in Nutshell with bi-directional, real-time sync. Activity and record changes in Customer.io update the matching contact or account in Nutshell, and CRM data flows the other way wherever Customer.io can store and use it.

Common use cases

  • Land delivery and engagement events (sent, opened, clicked, bounced) from reporting webhooks into a warehouse for attribution analysis.
  • Keep unsubscribe and subscription-preference state consistent between Customer.io and the CRM to avoid compliance gaps.
  • Push closed-won leads to accounting software to trigger invoicing automatically.
  • Keep People and Companies consistent between Nutshell and email marketing or outreach tools.

Where Customer.io runs outreach

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

Where Customer.io supplies contact or company data

Enriched fields land directly on records in Nutshell, and refreshes keep them from going stale.

Where Customer.io processes payments

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

What you can sync between Customer.io and Nutshell

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 Nutshell objects
Events Behavioral events sent via the Track API that trigger campaigns. Notes Free-text history attached to leads and contacts, replicated for a full timeline
Segments Attribute- or event-based groups; data syncs feed the attributes segments evaluate. Products Line items attached to leads, used to sync sold products into billing
Campaigns Automated workflows whose membership and metrics can be read via the App API. Tags Segmentation labels mapped to lists or filters in downstream tools
Broadcasts One-off sends to segments or audiences, triggerable via API. Users Rep records used to resolve ownership when syncing assignments
Deliveries / Messages Per-recipient message records whose lifecycle events flow out through reporting webhooks. Leads Nutshell's deal object; synced as the pipeline record linked to people and companies
Newsletters Recurring email sends with performance metrics available for reporting syncs. People Individual contacts, kept consistent with marketing and outreach tools
What ships with Customer.io ⇄ Nutshell

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

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

Real-time

Two-way sync

Changes in Customer.io or Nutshell instantly reflect in both systems. No stale data, no manual imports.

No-code + pro-code

Workflow automation

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

Observability

Monitoring

Track your Customer.io ⇄ Nutshell 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 Nutshell.

How the Customer.io and Nutshell 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

Nutshell

Integration surface
JSON-RPC API over HTTPS; a newer REST API is also offered
Authentication
HTTP Basic with account email and API key
Change detection
webhook subscriptions for record events, with polling as fallback
Capabilities
read · write · webhooks
Rate limits
subject to the platform's API rate limits
How it works

How to connect Customer.io to Nutshell — 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 Customer.io and Nutshell 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
    Customer.io connected
    Nutshell connected
    OAuth 2.0
    SSH tunnel
    SSL certificate
    VPC peering
  2. 02

    Choose tables

    Pick the Customer.io and Nutshell 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 · Customer.io ⇄ Nutshell
    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 Nutshell
    Company company_name text
    Email email text
    Amount amount numeric
    Created created_at timestamp
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FAQ

Customer.io and Nutshell 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 Customer.io and Nutshell.

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