@pfefferle @tallship @darnell @tallship Yes, but they are not required for federating with us. The inbox endpoint returns 406 Not Acceptable, so I think there's a problem with Content-Type header
Mitra adds Content-Type: application/ld+json; profile="https://www.w3.org/ns/activitystreams", this what ActivityPub spec requires:
https://www.w3.org/TR/activitypub/#server-to-server-interactions
Maybe @darnell expects a different content type.