dm property
DM is whether the transport carries a DIRECT message at all. True for slack, teams, telegram and whatsapp — whatsapp is nothing else, since the Cloud API addresses a person's number and there is no room a third party joins. False for discord, honestly: that ingress is guild-scoped slash commands — an interaction without a guild id is refused at the endpoint — so nothing ever arrives classified as a DM, no reply route is ever learned for one, and a send addressed at a Discord DM is refused 409.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
bool? dm;