  The description of dark matter as a pressure-less fluid and of dark energy as
a cosmological constant, both minimally coupled to gravity, constitutes the
basis of the concordance $\Lambda\text{CDM}$ model. However, the concordance
model is based on using equations of motion directly for the fluids with
constraints placed on their sources, and lacks an underlying Lagrangian. In
this work, we propose a Lagrangian model of two spin zero fields describing
dark energy and dark matter with an interaction term between the two along with
self-interactions. We study the background evolution of the fields as well as
their linear perturbations, suggesting an alternative to $\Lambda$CDM with dark
matter and dark energy being fundamental dynamical fields. The parameters of
the model are extracted using a Bayesian inference tool based on multiple
cosmological data sets which include those of Planck (with lensing), BAO,
Pantheon, SH0ES, and WiggleZ. Using these data, we set constraints on the dark
matter mass and the interaction strengths. Furthermore, we find that the model
is able to alleviate the Hubble tension for some data sets while also resolving
the $S_8$ tension.
