@vitaut systemd-shitpostd(8) is a standard part of systemd since version 42. It exposes shitposts on a typical (but legacy) D-Bus interface, and recently gained a new Varlink interface.
Together with systemd-networkd(8) and systemd-homed(8) it can be used to bootstrap a minimal ActivityPub server. User are mapped to AP actors, when mentioned the daemon replies with an entry from the local fortune db.
The user can control the daemon using shitpostctl(1) and configure it with shitpostd.conf(5).
apt install shitpostd
find_package(shitpostd)