SEATTLE -- Amazon employees have been testing it, but is the public ready for a cashier-less store?

More than a year after it introduced the concept, Amazon is opening its artificial intelligence-powered Amazon Go store today in downtown Seattle.

The store on the bottom floor of the company's Seattle headquarters allows shoppers to scan their smartphone with the Amazon Go app at a turnstile, pick out the items they want and leave.

By combining computer vision, machine learning algorithms and sensors, the online retail giant can tell what people have purchased and charges their Amazon account. If someone puts an item back, they aren't charged.

The store is not without employees -- Amazon said there will be people there making food, stocking shelves and helping customers. The store will offer ready-to-eat breakfasts, lunches, dinners and snacks, as well as some grocery staples like bread, milk, cheese and chocolates. It'll also have Amazon Meal Kits.

At about 1,800 square feet, the Amazon Go store adds to the company's growing physical store presence and its expansion into groceries after its purchase last year of organic grocer Whole Foods and its 470 stores.

Amazon now has more than a dozen Amazon Books stores, which also sell toys, electronics and small gifts. It has space in some Kohl's stores. Amazon also has small shops in several malls.

The company had announced the Amazon Go store in December 2016 and said it would open by early 2017, but it delayed the debut while it worked on the technology and company employees tested it.