  We study two-dimensional Jackiw-Teitelboim gravity on the disk topology by
using a BF gauge theory in the presence of a boundary term. The system can be
equivalently written in a supersymmetric way by introducing auxiliary gauginos
and scalars with suitable boundary conditions on the hemisphere. We compute the
exact partition function thanks to supersymmetric localization and we recover
the result obtained from the Schwarzian theory by accurately identifying the
physical scales. The calculation is then easily extended to the higher-spin
generalization of Jackiw-Teitelboim gravity, finding perfect agreement with
previous results. We argue that our procedure can also be applied to
boundary-anchored Wilson line correlators.
