  We consider the finite-frequency response of multiterminal Josephson
junctions and show how non-reciprocity in them can show up at linear response,
in contrast to the static Josephson diodes featuring non-linear
non-reciprocity. At finite frequencies, the response contains dynamic
contributions to the Josephson admittance, featuring the effects of Andreev
bound state transitions along with Berry phase effects, and reflecting the
breaking of the same symmetries as in Josephson diodes. We show that outside
exact Andreev resonances, the junctions feature non-reciprocal reactive
response. As a result, the microwave transmission through those systems is
non-dissipative, and the electromagnetic scattering can approach complete
non-reciprocity. Besides providing information about the nature of the weak
link energy levels, the non-reciprocity can be utilized to create
non-dissipative and small-scale on-chip circulators whose operation requires
only rather small magnetic fields.
