Mean-field approximation is often used to explore the qualitative behaviour of phase transitions in classical spin models before employing computationally costly methods such as the Monte-Carlo techniques. We implement a lattice site-resolved mean-field spin model that allows efficient simulation of phase transitions between phases of complex magnetic domains, such as magnetic helices, skyrmions, or states with canted spins. The framework is useful as a complementary approach for pre-screening the qualitative features of phase diagrams in complex magnets.