  We provide an explicit construction of a universal gate set for
continuous-variable quantum computation with microwave circuits. Such a
universal set has been first proposed in quantum-optical setups, but its
experimental implementation has remained elusive in that domain due to the
difficulties in engineering strong nonlinearities. Here, we show that a
realistic three-wave mixing microwave architecture based on the SNAIL [Frattini
et al., Appl. Phys. Lett. 110, 222603 (2017)] allows us to overcome this
difficulty. As an application, we show that this architecture allows for the
generation of a cubic phase state with an experimentally feasible procedure.
This work highlights a practical advantage of microwave circuits with respect
to optical systems for the purpose of engineering non-Gaussian states, and
opens the quest for continuous-variable algorithms based on few repetitions of
elementary gates from the continuous-variable universal set.
