  We present a holographic model of a topological Weyl semimetal. A key
ingredient is a time-reversal breaking parameter and a mass deformation. Upon
varying the ratio of mass to time-reversal breaking parameter the model
undergoes a quantum phase transition from a topologically nontrivial semimetal
to a trivial one. The topological nontrivial semimetal is characterised by the
presence of an anomalous Hall effect. The results can be interpreted in terms
of the holographic renormalization group (RG) flow leading to restoration of
time-reversal at the end point of the RG flow in the trivial phase.
