> ## 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.

# Shipping

> How an offer carries its own shipping profile.

In this document, you'll learn how an offer determines how its items ship.

## Shipping profile

Every offer points at a store's own **shipping profile** through its
`shipping_profile_id` field, joined via the read-only `offer ↔ shipping_profile`
link. The profile is what ties the offer's items to the store's shipping options
at checkout, so each store fulfills its slice of a multi-seller cart with its own
rates.

```ts theme={null}
await createOffersWorkflow(container).run({
  input: {
    offers: [
      {
        seller_id: "sel_123",
        created_by: "mem_123",
        variant_id: "variant_123",
        shipping_profile_id: "sp_123",
        sku: "ACME-WIDGET-01",
        prices: [{ amount: 2500, currency_code: "usd" }],
        inventory_items: [{ stock_levels: [{ location_id: "sloc_1", stocked_quantity: 50 }] }],
      },
    ],
  },
})
```

## Master products carry no profile

Master products live in the shared catalog and have no shipping profile of their
own. To keep multi-seller carts from losing their shipping methods on refresh,
`createOffersWorkflow` links the offer's **master product** to the offer's
shipping profile. The product↔profile link is one-to-one, so the first offer's
profile wins for a given master product. Later offers (including other stores'
offers on the same product) skip the link if a profile is already attached.

<Note>
  The one-to-one product↔profile link is a checkout-refresh accommodation, not
  the source of truth for how a store ships. Each offer still carries its own
  `shipping_profile_id`, which is what drives that store's fulfillment.
</Note>