ShippingCowDelivery promises for heavy items that AI shopping agents can read
AI shopping agents do not read your shipping policy page as prose; they read structured data, specifically the Schema.org OfferShippingDetails type nested inside your product's Offer markup. To make a heavy item's delivery promise machine-readable, you declare three things: the shipping cost, where it applies, and the delivery time split into handling time plus transit time, each in days.
The three declarations
shippingRate is the cost, shippingDestination is where the rule applies, and deliveryTime is the handling window plus the transit window. Each window is a minimum, a maximum and a unit of days.
For a heavy item, declare windows that reflect the slowest lane you serve, not a light-parcel default.
Sources
| Source | What we took from it |
|---|---|
| Google, "Supported structured data attributes and values" | OfferShippingDetails, deliveryTime, handlingTime and transitTime |
| Pendium, "One Thing to Watch Out For" | The three required properties |
| Pendium, "Map Shopify shipping schemas" | Handling and transit windows, and Shopify placement |
Sources checked on October 15, 2026.
Questions
What structured data type do AI agents look for? +
OfferShippingDetails. It is nested within an Offer using the shippingDetails property, and it tells a machine three things: what it costs to ship, where it ships to, and how long delivery takes (Google, "Supported structured data attributes and values," accessed 2026-10-15).
How do I structure the delivery time? +
deliveryTime points to a ShippingDeliveryTime object with two parts: handlingTime (order received to carrier handoff) and transitTime (carrier handoff to delivery). Each is a QuantitativeValue with a minimum, a maximum and a unit code of "d" for days (Google, "Supported structured data attributes and values," accessed 2026-10-15).
What are the three required properties? +
shippingRate, a MonetaryAmount with a numeric value and a currency code; shippingDestination, a DefinedRegion with an addressCountry in ISO 3166-1 alpha-2 code such as "US"; and deliveryTime, the handlingTime plus transitTime window (Pendium, "One Thing to Watch Out For," accessed 2026-10-15).
How does this apply to heavy items specifically? +
Heavy items have slower and more variable transit, so the handling and transit windows you declare must reflect reality, not a light-parcel default. For example, if a 100 lb order takes two to three days to hand off and two to four days in transit, you declare a handlingTime of 2 to 3 days and a transitTime of 2 to 4 days, and the agent computes a total window from the sum (Pendium, "Map Shopify shipping schemas," accessed 2026-10-15).
Where does the markup go in Shopify? +
Inside the product's existing JSON-LD offers block, which in a Dawn theme lives in the main product Liquid file. You append the shippingDetails block inside the offers array, using Liquid to pull the store's fulfillment times (Pendium, "Map Shopify shipping schemas," accessed 2026-10-15).
Does the promise have to be honest? +
Yes, for two reasons. First, an AI agent that recommends you on a delivery date you cannot hit damages the customer's trust in both of you. Second, marketplaces with on-time metrics measure against the promise, so an inflated promise becomes a late-shipment penalty. The promise should be the date you can reliably meet, not the date you would like to claim.
Is a delivery promise a binding commitment? +
A delivery promise is a stated date you will work to meet; it is what structured data declares. We do not frame delivery as a hard commitment, because a date you miss becomes a dispute and a chargeback risk. Declare a promise you can keep, and let the on-time record speak for it.
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