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

# Pricing & inventory

> Offer-scoped prices on the shared price set, and inventory linked to the offer.

In this document, you'll learn how an offer carries its own price and inventory
without owning the master variant.

## Offer-scoped pricing

An offer's prices don't live on a private price set. They live on the **master
variant's shared `PriceSet`**, with each offer-owned row scoped by a
`PriceRule` on the `offer_id` attribute. That's how many stores price the same
variant independently: every price row Mercur writes for an offer is stamped with
that offer's id, and reads filter the set back down to just that offer's rows.

```ts theme={null}
// Every offer price row is written with an offer_id rule on the shared price set
prices: [
  {
    amount: 2500,
    currency_code: "usd",
    rules: { offer_id: "offer_123" },
  },
]
```

The offer side reads its price ladder through the writable `offer ↔ price`
list-link, so `offer.prices` resolves in a single query traversal. Each row is a
standard Medusa money amount and supports `min_quantity` / `max_quantity` for
quantity-break pricing.

<Note>
  Because prices sit on the shared price set scoped by `offer_id`, the master
  variant is never mutated per store. The variant keeps a single price set, and
  the `offer_id` rule partitions it per offer.
</Note>

## Offer-scoped inventory

An offer's stock is held in Medusa `InventoryItem` records that link to the
**offer**, not to the variant. The `offer ↔ inventory_item` link is a list-link
whose pivot table (`offer_inventory_item`) carries a `required_quantity` column,
so one offer can draw on several inventory items, each with its own required
quantity.

<Warning>
  Offer inventory links to the **offer**, not the variant. `variant.inventory_items`
  is empty for offer-based orders. Always resolve stock through
  `offer.inventory_items`, never through the variant.
</Warning>

When you create an offer, its `inventory_items` entries each create a brand-new
`InventoryItem` (with optional starting `stock_levels`) and link it to the offer
in the same workflow run. An offer must have at least one inventory item.

```ts theme={null}
inventory_items: [
  {
    sku: "ACME-WIDGET-01",
    required_quantity: 1,
    stock_levels: [{ location_id: "sloc_1", stocked_quantity: 50 }],
  },
]
```

<Tip>
  The inventory items an offer creates are also linked to the store, so they show
  up under the store's inventory. To change the set of items on an existing
  offer, use the [batch inventory workflow](/platform/offer/guides/manage-offer-inventory).
</Tip>