  We present version 1.0 of our Lagrangian Numerical Relativity code
SPHINCS_BSSN. This code evolves the full set of Einstein equations, but
contrary to other Numerical Relativity codes, it evolves the matter fluid via
Lagrangian particles in the framework of a high-accuracy version of Smooth
Particle Hydrodynamics (SPH). The major new elements introduced here are: i) a
new method to map the stress--energy tensor (known at the particles) to the
spacetime mesh, based on a local regression estimate; ii) additional measures
that ensure the robust evolution of a neutron star through its collapse to a
black hole; and iii) further refinements in how we place the SPH particles for
our initial data. The latter are implemented in our code SPHINCS_ID which now,
in addition to LORENE, can also couple to initial data produced by the initial
data library FUKA. We discuss several simulations of neutron star mergers
performed with SPHINCS_BSSN_v1.0, including irrotational cases with and without
prompt collapse and a system where only one of the stars has a large spin
($\chi = 0.5)$.
