---
audience: engineers
summary: How imports work, name visibility, and multi-file ScaiCore source organization.
title: Module system
path: reference/language/module-system
status: published
---

```scaicore
// Importing
import { Invoice, LineItem } from "company/types"
import { validate_vat } from "scailabs/eu-utils@1.0"
import { CRM as SalesforceCRM } from "company/salesforce"

// Importing Core interfaces (for typed @core_call and @on)
import { BillingSpecialist } from "company/billing-specialist"

// Visibility
pub @flow public_flow { ... }          // Exported
@flow internal_flow { ... }             // Private to module
@internal @flow helper_flow { ... }     // Private + no entity key required
```

---