> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dodopayments.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Customer.io

> Send Dodo Payments events to Customer.io to trigger email automations and customer journeys.

## Introduction

Trigger personalized email campaigns and customer journeys based on payment events. Send welcome emails for new customers, subscription updates, and payment failure notifications automatically through Customer.io.

<Info>
  This integration requires your Customer.io Site ID and API Key.
</Info>

## Getting Started

<Steps>
  <Step title="Open the Webhook Section">
    In your Dodo Payments dashboard, navigate to <b>Webhooks → + Add Endpoint</b> and expand the integrations dropdown.

    <Frame>
      <img src="https://mintcdn.com/dodopayments/slbAEdrLLwKHfaRf/images/integrations/customer-io.png?fit=max&auto=format&n=slbAEdrLLwKHfaRf&q=85&s=fb4d96b67438c2eb178b2482475903db" alt="Add Endpoint and integrations dropdown" style={{ maxHeight: '500px', width: 'auto' }} width="1644" height="952" data-path="images/integrations/customer-io.png" />
    </Frame>
  </Step>

  <Step title="Select Customer.io">
    Choose the <b>Customer.io</b> integration card.
  </Step>

  <Step title="Enter Credentials">
    Provide your Customer.io Site ID and API Key in the configuration.
  </Step>

  <Step title="Configure Transformation">
    Edit the transformation code to format events for Customer.io's Track API.
  </Step>

  <Step title="Test & Create">
    Test with sample payloads and click <b>Create</b> to activate the sync.
  </Step>

  <Step title="Done!">
    🎉 Payment events will now trigger Customer.io email automations.
  </Step>
</Steps>

## Transformation Code Examples

### Track Payment Events

```javascript track_payments.js icon="js" expandable theme={null}
function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    webhook.url = "https://track.customer.io/api/v2/entity";
    webhook.payload = {
      type: "person",
      identifiers: {
        id: p.customer.customer_id
      },
      action: "payment_completed",
      name: "Payment Completed",
      attributes: {
        email: p.customer.email,
        name: p.customer.name,
        payment_amount: (p.total_amount / 100).toFixed(2),
        payment_method: p.payment_method || "unknown",
        payment_id: p.payment_id,
        currency: p.currency || "USD"
      }
    };
  }
  return webhook;
}
```

### Track Subscription Lifecycle

```javascript track_subscriptions.js icon="js" expandable theme={null}
function handler(webhook) {
  const s = webhook.payload.data;
  switch (webhook.eventType) {
    case "subscription.active":
      webhook.url = "https://track.customer.io/api/v2/entity";
      webhook.payload = {
        type: "person",
        identifiers: {
          id: s.customer.customer_id
        },
        action: "subscription_started",
        name: "Subscription Started",
        attributes: {
          email: s.customer.email,
          subscription_id: s.subscription_id,
          product_id: s.product_id,
          amount: (s.recurring_pre_tax_amount / 100).toFixed(2),
          frequency: s.payment_frequency_interval,
          next_billing: s.next_billing_date
        }
      };
      break;
    case "subscription.cancelled":
      webhook.url = "https://track.customer.io/api/v2/entity";
      webhook.payload = {
        type: "person",
        identifiers: {
          id: s.customer.customer_id
        },
        action: "subscription_cancelled",
        name: "Subscription Cancelled",
        attributes: {
          email: s.customer.email,
          subscription_id: s.subscription_id,
          cancelled_at: s.cancelled_at,
          cancel_at_next_billing: s.cancel_at_next_billing_date
        }
      };
      break;
  }
  return webhook;
}
```

### Track Customer Attributes

```javascript track_attributes.js icon="js" expandable theme={null}
function handler(webhook) {
  if (webhook.eventType === "payment.succeeded") {
    const p = webhook.payload.data;
    webhook.url = "https://track.customer.io/api/v2/entity";
    webhook.payload = {
      type: "person",
      identifiers: {
        id: p.customer.customer_id
      },
      action: "identify",
      name: "Customer Identified",
      attributes: {
        email: p.customer.email,
        name: p.customer.name,
        total_spent: (p.total_amount / 100).toFixed(2),
        payment_method: p.payment_method || "unknown",
        last_payment_date: webhook.payload.timestamp,
        customer_since: webhook.payload.timestamp
      }
    };
  }
  return webhook;
}
```

## Tips

* Use consistent event names that match your Customer.io campaigns
* Include relevant attributes for personalization
* Set proper customer identifiers for accurate tracking
* Use meaningful event names for campaign triggers

## Troubleshooting

<AccordionGroup>
  <Accordion title="Events not triggering campaigns">
    * Verify Site ID and API Key are correct
    * Check that event names match your Customer.io campaigns
    * Ensure customer identifiers are properly set
    * Review Customer.io API rate limits
  </Accordion>

  <Accordion title="Transformation errors">
    * Validate JSON structure matches Customer.io API format
    * Check that all required fields are present
    * Ensure event names and attributes are properly formatted
  </Accordion>
</AccordionGroup>