Autonomous robot company Marble is offering food deliveries in parts of San Francisco.
Sensors, camera and ultrasonic technology help the robot with navigation, but there is human oversight in case there is a problem.
Certain orders via the Yelp Eat24 app will offer the option of a robot delivery.
Marble plans to deliver groceries, parcels and other goods in the future.
Another company, Starship Technologies, began offering a pilot food delivery service in Washington DC and Redwood City, California earlier this year.