  From a planar algebra, we give a functorial construction to produce numerous
associated $C^*$-algebras. Our main construction is a Hilbert $C^*$-bimodule
with a canonical real subspace which produces Pimsner-Toeplitz, Cuntz-Pimsner,
and generalized free semicircular $C^*$-algebras. By compressing this system,
we obtain various canonical $C^*$-algebras, including Doplicher-Roberts
algebras, Guionnet-Jones-Shlyakhtenko algebras, universal
(Toeplitz-)Cuntz-Krieger algebras, and the newly introduced free graph
algebras. This is the first article in a series studying canonical
$C^*$-algebras associated to a planar algebra.
