CQRS

Corvis has no CQRS module: there are no command, query or event buses with handlers registered by type, and no sagas.

Alternative: services and EventEmitter

For most applications it is enough to separate reads from writes into different services and publish domain events with the framework's event emitter. This is the pattern examples/tertulia uses: creating a room over REST reaches the WebSocket clients through an event.

#[module(
    imports = [EventEmitterModule::for_root(EventEmitterOptions::default())],
    /* ... */
)]
pub struct AppModule;

The write side publishes the event (src/rooms/rooms_service.rs):

#[injectable]
pub struct RoomsService {
    db: Arc<OrmService>,
    events: Arc<EventEmitter>,
}

impl RoomsService {
    pub async fn create(&self, dto: CreateRoomDto, created_by: &str) -> Result<Room, OrmError> {
        let room: Room = self
            .db
            .room()
            .create(json!({
                "data": { "name": dto.name, "topic": dto.topic, "maxMembers": dto.max_members, "createdBy": created_by }
            }))
            .await?;
        self.events.emit("room.created", room.clone());
        Ok(room)
    }
}

And any provider reacts with a handler (src/chat/chat_gateway.rs):

#[handlers]
impl ChatGateway {
    #[on_event("room.created")]
    fn on_room_created(&self, room: Room) {
        self.server.emit("room_created", json!({ "room": room, "members": [] }));
    }
}

The handler receives the same type that was emitted (here Room). See Events for wildcards and emitter options.

If you need a command bus with one handler per type, you can build it as your own provider; there is no official implementation.