Bjet_MCMC is a tool to to automatically model multiwavelength spectral energy distributions of blazars, considering one-zone synchrotron-self-Compton (SSC) model with or without the addition of external inverse-Compton process from the thermal emission of the nucleus. It also contains manual fitting functionalities for multi-zone SSC modeling. This tool is built as a MCMC python wrapper around the C++ code Bjet. Below are the updates made for this specific version. Multi-zone: EIC from jet particles onto blob synchrotron emission is now taken into account. Found and fixed a bug only happening in the multi-zone model (issue with radiative transfer for Jet SSC emission). Outputs: Added a bjet.log file output that contains some extra physics values from bjet. Fixed some issues on handling frozen parameters for the simple SSC model. Resolved an issue with the report text file for fixed parameters. Fixed a small typo affecting the display of energy bins in "model_and_data.svg". Replace parameters names alpha_1 and alpha_2 by n_1 and n_2 for more consistency. Fitting method: Upper limits are now included in the fitting process (P=0.95 below, P=0.05 above). Documentation: Implemented external documentation with readthedocs (https://bjet-mcmc.readthedocs.io/en/latest/). Other: New logo.