Get one Subway store's full menu

Returns one Subway store's complete menu: every category, every product, and for each purchasable size (Footlong, 6-inch, etc.) its price, full nutrition panel (calories, fat, sodium, protein and more) and allergen disclosures. Store IDs come from a GET /subway/store result's store_id field. This endpoint currently covers US stores only: the menu is not available for non-US stores, which return 404 -- see GET /subway/combos for the bundle/combo categories that are available in other markets. Categories carry is_main_category: true for human-browsable menu sections (Sandwiches, Drinks, Salads, ...) and false for Subway's own internal build/customization groupings, which are included for completeness but are not meant to be shown as menu sections on their own.