how do i stop my roomba i3+ from falling down the stairs? my home base is in the hallway near them.

You need to move your Home Base. This is a critical safety step to prevent the robot from tumbling down.

1. Unplug the Home Base and pick it up.
2. Find a new location that is at least 4 feet (1.2 meters) away from the top of the stairs. This distance is required in front of the Home Base and to both sides.
3. Ensure there is at least 1.5 feet (0.5 meters) of clear space on both sides of the Home Base and 4 feet in front of it for proper docking.
4. Plug it back in and re-dock your robot.

If that didn't work because your layout won't allow a 4-foot clearance, you must use a physical barrier. If the room contains a balcony or stairs, a physical barrier should be used to prevent access and ensure safe operation.

Heads up: The robot moves on its own. Always be aware when walking in the area it's operating in to avoid stepping on it. Supervise small children and pets when the robot is running.