  We present a global likelihood function in the space of dimension-six Wilson
coefficients in the Standard Model Effective Field Theory (SMEFT). The
likelihood includes contributions from flavour-changing neutral current B
decays, lepton flavour universality tests in charged- and neutral-current B and
K decays, meson-antimeson mixing observables in the K, B, and D systems, direct
CP violation in K -> {\pi}{\pi}, charged lepton flavour violating B, tau, and
muon decays, electroweak precision tests on the Z and W poles, the anomalous
magnetic moments of the electron, muon, and tau, and several other precision
observables, 265 in total. The Wilson coefficients can be specified at any
scale, with the one-loop running above and below the electroweak scale
automatically taken care of. The implementation of the likelihood function is
based on the open source tools flavio and wilson as well as the open Wilson
coefficient exchange format (WCxf) and can be installed as a Python package. It
can serve as a basis either for model-independent fits or for testing dynamical
models, in particular models built to address the anomalies in B physics. We
discuss a number of example applications, reproducing results from the EFT and
model building literature.
