More and more often, as retail giant Walmart finds that it doesn't yet have the resources to compete in digital commerce with Amazon, it is identifying partners who can narrow the gap.

Case in point: In late October, even as the online monolith was grabbing headlines with the introduction of Amazon Key, a new delivery service that allows couriers to open a purchaser's front door with a compatible smart lock, the world's largest brick-and-mortar retailer was already testing an even more advanced program.

Whereas Amazon Lock would enable inside-the-door delivery, a Walmart partnership with August, a smart-lock manufacturer, would take the concept of security a step further, with even the convenience of fresh produce delivered not just inside your home, but to the shelves of your refrigerator.

As August describes the process, an online shopper places an order on Walmart.com and the goods, including groceries, are delivered to the customer's home. If no one answers a doorbell ring, the driver receives a one-time, limited-window passcode that unlocks the door.