  We experimentally study electron transport between two superconducting indium
leads, coupled to the WTe$_2$ crystal surface. WTe$_2$ is characterized by
presence of Fermi arc surface states, as a predicted type-II Weyl semimetal
candidate. We demonstrate Josephson current in unprecedentedly long 5~$\mu$m
In-WTe$_2$-In junctions, which is confirmed by $I-V$ curves evolution with
temperature and magnetic field. The Josephson current is mostly carried by the
topological surface states, which we demonstrate in a double-slit SQUID
geometry, realized by coupling the opposite WTe$_2$ crystal surfaces.
