(Reuters) - Wal-Mart Stores Inc is testing a service to stock groceries directly to customers’ refrigerators as it seeks to take on e-commerce giant Amazon.com.

The delivery of groceries and meal kits is emerging as the next frontier of competition among retailers.

The world's biggest brick-and-mortar retailer said on Friday it is partnering with August Home, a provider of smart locks and home accessories, to test the service with certain customers in the Silicon Valley. (bit.ly/2ffqqvT)

The grocery business is set to be upended through Amazon’s acquisition of upmarket grocer Whole Foods last month and the online retailer is also entrenching itself more deeply in the restaurants business.

Amazon Restaurants on Friday teamed up with online food ordering company Olo whose network of restaurants includes Applebee’s and Chipotle.

The partnership will help Olo’s restaurant customers connect with Amazon’s delivery services.

The competition in the meal-kits business is also heating up. Supermarket operator Albertsons Cos Inc said it would buy meal-kit delivery service Plated while rival Kroger-owned Ralphs started selling meal kits in stores this week.

ONE-TIME PASSCODE DELIVERY

As part of the test, Wal-Mart delivery persons gain access to a customer’s house using a pre-authorized one-time passcode and put away groceries in the fridge and other items in the foyer.

Homeowners would receive notifications when the delivery is in progress and could also watch the real-time process from their home security cameras through the August Home app.

The Bentonville, Arkansas-based retailer has been exploring new methods of delivery and in June said it was testing using its own store employees to deliver packages ordered online.