We investigate the adsorption of a Ni monolayer on the beta -SiC (001) surface by means of highly precise first-principles all-electron full-potential linearized augmented plane wave calculations. Total-energy calculations for the Si- and C-terminated surfaces reveal high Ni-SiC adsorption energies, with respect to other metals, confirmining the strong reactivity and the stability of the transition metal/SiC interface. These high binding energies, about 7.3-7.4 eV, are shown to be related to strong p-d hybridization, common to both surface terminations and different adsorption sites and despite the large mismatch, can stabilize overlayer growth. A detailed analysis of the bonding mechanism, hybridization of the surface states, charge transfer, and surface core level shifts reveals the strong covalent character of the bonding. After a proper accounting of the Madelung term. the core-level shift is shown to follow the charge-transfer trend.