  A family of multispecies Ising models on generalized regular random graphs is
investigated in the thermodynamic limit. The architecture is specified by
class-dependent couplings and magnetic fields. We prove that the
magnetizations, neighbours correlations and free energy converge to suitable
functions evaluated at the solution of a belief propagation fixed point
equation. In absence of magnetic fields, a phase transition is identified and
the corresponding critical parameters are determined by the spectral radius of
a low-dimensional matrix.
