The PGXN client is an external application, written in Python, that works as a command-line interface to PGXN. The application, named pgxnclient, works by means of commands, which are actions such as install, download, uninstall, and so on, allowing a database administrator to instrument PGXN and work with extensions.
To some extent, pgxnclient works the same as the command cpan (or cpanm) for Perl, zef for Raku, pip for Python, and so on.
Being an external application means that pgxnclient is not distributed with PostgreSQL, and therefore you need to install it on your machines before you can use it. Installing pgxnclient is not mandatory in order to use PostgreSQL extensions, but it can make your life a lot easier.
In the following subsections, you will see how to install pgxnclient on main Unix and Unix-like operating systems, but before that, it is important to let you know that, once installed, you will find two executables on your system: pgxn and pgxnclient...