A cluster ensemble is a pair

of positive spaces (i.e. varieties equipped with positive atlases), coming with an action of a symmetry group

. The space

is closely related to the spectrum of a cluster algebra [
12]. The two spaces are related by a morphism

. The space

is equipped with a closed

-form, possibly degenerate, and the space

has a Poisson structure. The map

is compatible with these structures. The dilogarithm together with its motivic and quantum avatars plays a central role in the cluster ensemble structure. We define a non-commutative

-deformation of the

-space. When

is a root of unity the algebra of functions on the

-deformed

-space has a large center, which includes the algebra of functions on the original

-space. The main example is provided by the pair of moduli spaces assigned in [
7] to a topological surface

with a finite set of points at the boundary and a split semisimple algebraic group

. It is an algebraic-geometric avatar of higher Teichmüller theory on

related to

. We suggest that there exists a duality between the

and

spaces. In particular, we conjecture that the tropical points of one of the spaces parametrise a basis in the space of functions on the Langlands dual space. We provide some evidence for the duality conjectures in the finite type case.