Many important problems in solid mechanics involve non-trivial constitutive models that are difficult to express in variational form. It is therefore challenging to express these problems in domainspecific languages that work at the variational form level. We introduce a framework for FEniCSx / DOLFINx that allows for the straightforward implementation of a wide range of constitutive models. The application of the framework is demonstrated by implementing a von Mises elastoplastic material model with hardening using JAX and Numba software.Many important problems in solid mechanics involve non-trivial constitutive models that aredifficult to express in variational form. It is therefore challenging to express these problems in domainspecific languages that work at the variational form level.We introduce a framework for FEniCSx / DOLFINx that allows for the straightforward implementation of a wide range of constitutive models. The application of the framework is demonstrated by implementing a von Mises elastoplastic material model with hardening using JAX and Numba software.