When a party member doesn't have Keystone Companion installed, but does have the details! addon, It's possible to receive keystone information from details.

This needs to be added in so that Keystone Companion can display the dungeon and keystone level. Inventory info will not be available for details! players - in order to sync inventory information, Keystone Companion needs to be installed and enabled.

This feature is now included in Beta 2.