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

# Integration

> How Charlie integrates with Shopify without adding complexity

Charlie extends Shopify's native order routing capabilities without introducing infrastructure complexity or IT maintenance overhead.

## Checkout-native execution

Charlie's routing logic operates as **Shopify Functions**, executing natively within Shopify's infrastructure during checkout.

* No external API calls
* No latency added to checkout
* All routing decisions occur before payment

```mermaid theme={"system"}
sequenceDiagram
    participant Customer
    participant Shopify as Shopify Checkout
    participant Charlie as Charlie OMS
    participant Payment as Payment Gateway

    Customer->>Shopify: Enters shipping address
    
    Shopify->>Charlie: Which locations can fulfill this order?
    Note right of Charlie: Apply constraints & preferences
    Charlie-->>Shopify: Return optimal locations
    
    Shopify->>Shopify: Calculate shipping options
    Shopify-->>Customer: Display available shipping methods
    
    Customer->>Payment: Complete payment
    Payment-->>Shopify: Order confirmed
```

## Enhancement layer

Charlie augments Shopify's native functionality rather than replacing it. No middleware, no custom API development.

| Shopify Native       | Charlie Enhancement               |
| -------------------- | --------------------------------- |
| Available inventory  | Safety stock & sellable inventory |
| Native order routing | Advanced routing rules            |
| Location management  | Daily capacity & performance data |
| Checkout process     | Fulfillment constraints           |

## IS/IT impact

<CardGroup cols={2}>
  <Card title="Zero IT burden" icon="check">
    No integration requirements, no ongoing maintenance
  </Card>

  <Card title="No ERP integration needed" icon="plug">
    Routing happens at checkout, before orders exist
  </Card>

  <Card title="Auto-evolving" icon="arrows-rotate">
    Updates automatically with Shopify—no version conflicts
  </Card>

  <Card title="Clean uninstall" icon="trash">
    All data in Shopify metafields—remove app without data loss
  </Card>
</CardGroup>

<Note>
  Routing decisions occur at checkout before orders are placed. Existing fulfillment workflows remain unchanged, and internal teams continue using Shopify admin without modification.
</Note>

## Related

<CardGroup cols={2}>
  <Card title="Security" icon="shield" href="/enterprise/security">
    Data governance and security controls
  </Card>

  <Card title="Scalability" icon="chart-line" href="/enterprise/scalability">
    Performance and availability
  </Card>
</CardGroup>