Reality is fundamentally material, where materiality is defined as existing in three dimensions in space and time, or in spacetime. Everything in reality is fundamentally an object, that is, something that exists independent of any mind perceiving it. Minds are also fundamentally objects or collections of objects, all of which are material, as defined above.
The fundamental substance of reality is matter, which is three dimensional objects that exist in space and time. There is no more to the nature of reality than this.