---
sidebar_label: 'Items'
sidebar_position: 5
---

# Items

An item is either a **Product** or a **Container**.

- A **Product** is a sellable item in a menu — for example, a snack bar, a burger, or a coffee. It appears at the root of the menu or as a selectable option inside a Container.
- A **Container** is a configurable slot inside a Product. It holds a list of Products that the customer can select or deselect.

## Alternation rule

Products and Containers alternate strictly in the hierarchy:

- A Product's `configItems` collection can only contain Containers.
- A Container's `configItems` collection can only contain Products.

This guarantees a clean, predictable nesting structure.

## Container selection options

A Container's behaviour is controlled by several properties:

| Property | Description |
|----------|-------------|
| `min` | Minimum number of products the customer must select (0 = optional) |
| `max` | Maximum number of products the customer can select (unbounded = no limit) |
| `isNegated` | When `true`, selected products represent _removals_ (e.g. a "Remove" container) |
| `isSelectedByDefault` | On a product inside a container: whether it is pre-selected for the customer |

### Example: hamburger with Add, Remove, and Select Bread

```
Hamburger — id: 1, type: product, price: 47
  Add — id: 2, type: container, min: 0, max: unbounded
    Bacon — id: 3, type: product, price: 5, isSelectedByDefault: false
    Tomato — id: 4, type: product, price: 3, isSelectedByDefault: false
    Cheese — id: 5, type: product, price: 3, isSelectedByDefault: false
  Remove — id: 6, type: container, min: 0, max: unbounded, isNegated: true
    Tomato — id: 4, type: product, price: 0, isSelectedByDefault: false
    Cheese — id: 5, type: product, price: 0, isSelectedByDefault: false
  Select Bread — id: 7, type: container, min: 1, max: 1
    Normal Bread — id: 8, type: product, price: 0, isSelectedByDefault: true
    Gluten Free Bread — id: 9, type: product, price: 0, isSelectedByDefault: false
    Luxury Bread — id: 10, type: product, price: 5, isSelectedByDefault: false
```

If a customer adds Bacon, removes Cheese, and changes to Luxury Bread, the total is:

```
47 (burger) + 5 (bacon) + 0 (remove cheese) + 5 (luxury bread) = 57
```

## Item visibility

For an item to be visible to a customer it must either be presented by one of the categories or subcategories in the Menu Instance, or be surfaced by an upselling rule.