Lists the plugged-in retailers and their capabilities (product page, store selection, minimum order, booked slot). With check: true, also checks that each session responds and shows the active store.

Searches the retailer's catalogue. For each product: id, label (brand and size included), price, price per kg/l/piece, availability, typed promotions (immediate, multibuy, loyalty) and best net offer.

Reads a product page: ingredient list (allergens in capitals, possible traces), allergen statement if the site provides it, and origin. Ingredients are null for a raw product (fruit, fresh meat).

Reads the retailer's actual cart: lines (id, label, quantity, line total, unit price) and total.

Reads, for one retailer or all of them (store omitted), the selected store, the booked slot, the next pickup and delivery slots (structured dates) and the minimum order. Books nothing.

Adds units of a product on top of those already present, then reads the cart back to confirm.

Sets a product's quantity in the cart (replaces the current one; 0 removes the product), then reads the cart back.

Removes a product from the cart entirely, then reads the cart back.

The retailer's stores around a postcode or town, nearest first (if the retailer supports it, see list_stores).

Selects the retailer's active store among the find_stores results and remembers it. The site session must be on this store: on "session expired", open it on the site.

Reads each retailer's cart: total, lines, minimum order and missing amount, next slots. Sorted from cheapest to most expensive.