Cart predicate language

Cart predicates are boolean expressions evaluated against the current cart.

Thor uses them to decide whether a checkout rule is eligible. If the predicate returns true, the rule can apply. If it returns false, the rule is ignored for that cart.

Use this language for:

• CartDiscount.predicate
• ShippingMethod.predicate
• AbsoluteShippingMethodRate.predicate
• RelativeShippingMethodRate.predicate

Empty predicates are treated as true.

Thor evaluates cart predicates against resolved checkout data.

Common top-level fields include:

• customer
• shipping_address
• billing_address
• total
• subtotal
• currency_code
• store
• price_channel
• line_items

That means predicates describe business eligibility, not frontend state.

Most production predicates follow a few repeatable patterns:

• customer targeting
• country or address targeting
• minimum subtotal checks
• line-item filtering

Keep the predicate focused on eligibility. Put cart-wide eligibility on the main discount or shipping rule, and line-item-specific checks on line-item target predicates.