  We study $\widehat{\text{CGHS}}$ gravity, a variant of the matterless
Callan-Giddings-Harvey-Strominger model. We show that it describes a universal
sector of the near horizon perturbations of non-extremal black holes in higher
dimensions. In many respects this theory can be viewed as a flat space analog
of Jackiw-Teitelboim gravity. The result for the Euclidean path integral
implies that $\widehat{\text{CGHS}}$ is dual to a Gaussian ensemble that we
describe in detail. The simplicity of this theory allows us to compute exact
quantities such as the quenched free energy and provides a useful playground to
study baby universes, averages and factorization. We also give evidence for the
existence of a non-perturbative completion in terms of a matrix model. Finally,
flat wormhole solutions are discussed.
