Puppet version 2 reports, if the "config_version" parameter is set in puppet.conf on the master, return a version number/string for the current configuration in the "configuration_version" field:

--- !ruby/object:Puppet::Transaction::Report
  configuration_version: "210" 
  host: jantmanvm2.eng.techtarget.com
  kind: apply

It would be nice if this value was parsed (if present) along with the report, stored, and (ideally) brought out to be stored along with the report object (so the report object has reported_at, created_at, updated_at, status, config_version) and easily accessible in host views. Specifically, I'd envision this displayed:

1. On the top-level reports page as a new column
2. On the statistics page, as a new graph
3. Optionally, displayed in the hosts table (maybe in the Last Report column where the time is currently shown)?
4. On the host details page, perhaps in the Properties table (Last Config Version)
5. Somewhere on the report details/log page

It has relatively low priority for me, but I can probably get around to submitting a patch for the UI stuff, a bit unsure about the report parsing and data storage though. Maybe it's best to just wait and see if Puppet will expose this as a fact...