  We present the open-source SIMUnet code, designed to fit Standard Model
Effective Field Theory (SMEFT) Wilson coefficient alongside Parton Distribution
Functions (PDFs) of the proton. SIMUnet can perform SMEFT global fits, as well
as simultaneous fits of the PDFs and of an arbitrarily large number of SMEFT
degrees of freedom, by including both PDF-dependent and PDF-independent
observables. SIMUnet can also be used to determine whether the effects of any
New Physics models can be fitted away in a global fit of PDFs. SIMUnet is built
upon the open-source NNPDF code and is released together with documentation,
and tutorials. To illustrate the functionalities of the new tool, we present a
new global analysis of the SMEFT Wilson coefficients accounting for their
interplay with the PDFs. We increment our previous analysis of the LHC Run II
top quark data with both (i) the Higgs production and decay rates data from the
LHC, and (ii) the precision electroweak and diboson measurements from LEP and
the LHC.
