The company said it can be remote-controlled when not at home, to check on pets, people, or home security.
It can also patrol a home automatically and send owners a notification if it detects something unusual.
Amazon said it was more than "Alexa with wheels" and had been programmed with a range of movements and expressions to give it personality.
It demonstrated asking Astro to "beatbox" - and the robot bopped its head and made expressions while playing hip-hop beats.
Amazon was also keen to pre-empt privacy concerns.
It said Astro can be set with "out of bounds" zones, so it cannot go into certain areas, or could be set to "do not disturb". It also features buttons to turn off cameras and microphones - though it loses its ability to move around when they are switched off.
The small robot also comes equipped with an extendable "periscope" camera that pops up from its head. Amazon showed an example of using it to check if a gas hob had been left on after leaving the house.