I will discuss the quantisation of de Sitter JT gravity in the canonical formalism to illustrate constructions of Hilbert spaces in quantum gravity.  Our aim is a description of states which makes spacetime locality manifest with a positive inner product, which is challenging due to the Hamiltonian constraints.  The key ideas include representing states either as “invariants” (solutions to the Wheeler-DeWitt equation) or dual “co-invariants” (equivalence classes under gauge transformations), defining a physical inner product by group averaging, and relating this to Klein-Gordon inner products via gauge-fixing conditions.