# Puppet Development # Facters Custom facters are usually created in the `code/modules/profile/lib/facter` directory inside the [puppet repository](https://gitea.psi.ch/puppet/puppet/src/branch/preprod/code/modules/profile/lib/facter) Testing Facters on the machine (without a Puppet run) ``` FACTERLIB=/opt/puppetlabs/puppet/cache/lib/facter facter users ```