Under Mac, make sure you have Homebrew installed and that your shell is Bash rather than zsh
Check out the source code from GitHub and enter the newly created directory:
git clone https://github.com/zatosource/zato && cd zato/code
./install.sh
./bin/zato --version # Output -> Zato <major>.<minor>+rev.<nnn>-py3.n.n-<system-version>
That concludes the process - you can refer to the main documentation index now.