Canonical queries define the data-fetching contract between the frontend and your connector app. When you build an ecommerce connector, you implement query handlers for each of these queries so the frontend can retrieve products, categories, carts, and other resources from your commerce backend.
Each query has a name (used to register the handler), an entity type (the shape of data it returns), a type (single for one result, multi for paginated lists), and an input schema (the parameters the frontend sends).
Import these from @laioutr-core/canonical-types/ecommerce.