Astral Window (EFA - A)

You cause a doorway-sized portal to appear in the air at a point you can see within range, through which you and other creatures can peer into the Astral Plane. If you move more than 30 feet from the portal, it disappears.

You can state an object or creature's name, and a vision of it appears in the window. If the object or creature is not on the Astral Plane, the window shows a random location thereon.

The window shows both sides, so a creature you see through the window also sees you.
A creature cannot pass through the window, attack through it, or cast spells through it unless you allow it or it makes a Wisdom saving throw with disadvantage.

An astral window you create counts as a portal for Astral Projection spells.