This is a 'totem' that will hold four add-on badges as implemented in the DC26 shitty add-on standard. There are provisions for two AA batteries (optional, if you want to power them externally), a lanyard hole, and a 1x4 header breaking out VCC, SDA, SCL, and GND. Basically, it's the shittiest thing you can imagine.
How does this connect to Badge add-ons?
There you go. Gerbers available in this project. Also available as a shared project on OshPark: https://oshpark.com/shared_projects/uYwa5w3S