  Multiwavelength observations are now the norm for studying blazars' various
states of activity, classifying them, and determining possible underlying
physical processes driving their emission. Broadband emission models became
unavoidable tools for testing emission scenarios and setting values to physical
quantities such as the magnetic field strength, Doppler factor, or shape of the
particle distribution of the emission zone(s). We announce here the first
public release of a new tool, Bjet_MCMC, that can automatically fit broadband
spectral energy distributions (SEDs) of blazars. The complete code is available
on GitHub and allows testing leptonic synchrotron self-Compton models (SSC),
with or without external inverse-Compton processes from the thermal environment
of supermassive black holes (accretion disk and broad line region). The code is
designed to be user-friendly and computationally efficient. It contains a core
written in C++ and a fully parallelized SED fitting method. The original
multi-SSC zones model of Bjet is also available on GitHub but is not included
in the MCMC fitting process at the moment. We present the features,
performance, and results of Bjet_MCMC, as well as user advice.
