To install the GNU Taler Debian packages, first ensure that you have the right Debian distribution. At this time, the packages are built for Sid, which means you should use a system which at least includes unstable packages in its source list. We recommend using APT pinning to limit unstable packages to those explicitly requested. To do this, set your ``/etc/apt/preferences`` as follows: .. code-block:: Package: * Pin: release a=stable Pin-Priority: 700 Package: * Pin: release a=testing Pin-Priority: 650 Package: * Pin: release a=unstable Pin-Priority: 600 Package: * Pin: release l=Debian-Security Pin-Priority: 1000 A typical ``/etc/apt/sources.list`` file for this setup would look like this: .. code-block:: deb http://ftp.ch.debian.org/debian/ buster main deb http://security.debian.org/debian-security buster/updates main deb http://ftp.ch.debian.org/debian/ testing main deb http://ftp.ch.debian.org/debian/ unstable main deb https://deb.taler.net/apt/debian sid main The last line is crucial, as it adds the GNU Taler packages. Next, you must import the Taler Systems SA public package signing key into your keyring and update the package lists: .. code-block:: console # wget -O - https://taler.net/taler-systems.gpg.key | apt-sign add - # apt update .. note:: You may want to verify the correctness of the Taler Systems key out-of-band. Now your system is ready to install the official GNU Taler binary packages using apt.