  We revisit the holographic dictionary for a free massless scalar in AdS$_3$,
focusing on the `singleton' solutions for which the boundary profile is an
arbitrary chiral function. We look for consistent boundary conditions which
include this class of solutions. On one hand, we give a no-go argument that
they cannot be interpreted within any boundary condition which preserves full
conformal invariance. On the other hand, we show that such solutions fit
naturally in a generalization of the Comp\`{e}re-Song-Strominger boundary
conditions, which preserve a chiral Virasoro and current algebra. These
observations have implications for the black hole deconstruction proposal,
which proposes singleton solutions as candidate black hole microstate
geometries. Our results suggest that the chiral boundary condition, which also
contains the extremal BTZ black hole, is the natural setting for
holographically interpreting the black hole deconstruction proposal.
