Facter does not show custom Puppet facts

The best practise is to put any facts and other plugins within modules on the puppet server. Then use the pluginsync feature on the client. This lets the puppet client put things in the appropriate location.

http://docs.puppetlabs.com/guides/plugins_in_modules.html

{modulepath}
└── {module}
    └── lib
        |── augeas
        │   └── lenses
        ├── facter
        └── puppet
            ├── parser
            │   └── functions
            ├── provider
            |   ├── exec
            |   ├── package
            |   └── etc... (any resource type)
            └── type

So a new fact might go into modules/examplemod/lib/facter/myfact.rb.

Since facter-1.7 there's also the possibility to have external facts, that can be deployed in /etc/facter/facts.d and can be written in any language.

This is actually a bug in Puppet 3.6, apparently.

As an aside, note that using agents that are newer than the master is not generally supported.