Amazon has opened its first-ever full-size, "cashierless" grocery store, providing shoppers an experience that does not require any human interaction.

The project, called Amazon Go Grocery, has been in development for five years. Starting Tuesday, customers can scan a QR code from Amazon's mobile app, walk into the Seattle store, take any item they want to purchase and walk out without paying at a cashier station.

Amazon said it is employing technology that senses when a product is taken from or returned to a shelf and keeps track of items in a virtual cart. When a customer leaves, they are sent a receipt and their Amazon account is charged.

The first and so far only Amazon Go Grocery store sits at 10,400 square feet, while a typical grocery store averages 40,000 square feet, CNBC reported.

The new store contains nearly 5,000 items, including produce, dairy, packaged seafood, meats, baked goods, meal kits, household items and a full liquor selection.

It includes some items sourced from Whole Foods providers, though an executive told CNBC that the Amazon Go Grocery story aims to complement brands that can be found at Whole Foods.

The same cashierless scanning technology has previously been used at several Amazon Go locations, designed to service business centers with breakfast and lunch foods.

The new Amazon Go Grocery is created for consumers to fill their pantries with items to cook meals at home, not just premade food.

Cameron Janes, the vice president of Amazon's physical retail division, told CNBC that fine-tuning the scanners to detect shoppers grabbing and bagging their items in the store was the "biggest incremental challenge ... to enable customers just to shop and not have to worry about the technology."

"We're just getting started here," Janes said. "I think what we're trying to do here — and with all of our physical stores — is really work backwards from the customer, and deliver some differentiation."

The store will have several employees on staff to start, helping with stocking shelves and aiding any shoppers who may need assistance.

A report from The Information said Amazon's predicted annual revenue, from $28 million in 2018 to above $639 million in 2020, has proved to be lower than anticipated. Amazon declined to comment to CNBC about the numbers.

"We believe we can be profitable," Janes said in regard to Amazon's grocery division.

The physical retail unit for the company was the only division to report a sales slowdown during the fourth quarter, with revenue declining 1 percent year over year to $4.36 billion.