We present accurate and efficient computations of large scale structure observables, obtained with a modified version of the c l ass code which is made publicly available. This code includes all relativistic corrections and computes both the power spectrum C-l(z(1), z(2)) and the corresponding correlation function xi(theta, z(1), z(2)) of the matter density and the galaxy number fluctuations in linear perturbation theory. For Gaussian initial perturbations, these quantities contain the full information encoded in the large scale matter distribution at the level of linear perturbation theory. We illustrate the usefulness of our code for cosmological parameter estimation through a few simple examples.