Optional
roomThe state events to reconcile metadata from
Optional
timelineWhether the timeline was empty before the marker event arrived in the room. This could be happen in a variety of cases:
syncFromCache
A marker event refers to UNSTABLE_MSC2716_MARKER
and indicates that
history was imported somewhere back in time. It specifically points to an
MSC2716 insertion event where the history was imported at. Marker events
are sent as state events so they are easily discoverable by clients and
homeservers and don't get lost in timeline gaps.
Whether to insert the new event at the start of the timeline where the oldest events are (timeline is in chronological order, oldest to most recent)
Whether to add timeline events to the state as was done in legacy sync v2. If true then timeline events will be added to the state. In sync v2 with org.matrix.msc4222.use_state_after and simplified sliding sync, all state arrives explicitly and timeline events should not be added.