| at | No | OPTIONAL. The session's current start ("10:30 AM"), to tell apart sessions with the same title. | |
| end | No | The new end, same forms. Left out on move_time, the session keeps its length. | |
| date | No | OPTIONAL. The day, YYYY-MM-DD, when the event runs more than one day or the session moves to another day. | |
| kind | No | REQUIRED for a preview. move_time (pass `start`, optionally `end` and `date`), move_room (pass `room`), rename (pass `title`), cancel, add_session (pass `title`, `start`, `end`, `room`, optionally `date` and `speakers`). | |
| room | No | The room or place label, plain words. | |
| start | No | The new start: "4:30 PM", or a full timestamp with a time zone. Read in the event's own time zone. | |
| title | No | The new or added session's title. | |
| notify | No | OPTIONAL. A time or room move notifies pass holders by default; cancel, rename and add are quiet unless this is true. False keeps any change quiet. | |
| confirm | No | Leave out for the PREVIEW. Only after the organizer says yes to the preview, call again with confirm: true and the changeId. | |
| changeId | No | REQUIRED with confirm: the changeId the preview returned. | |
| speakers | No | OPTIONAL, for add_session: speaker names; a name that matches the event's speakers is linked, any other is kept as a plain name. | |
| sessionId | No | The session's id exactly as the agenda or a candidates list gave it. Never made up. | |
| sessionTitle | No | Or the session's title as the agenda spells it, when there is no sessionId. | |
| eventIdOrName | Yes | REQUIRED. The event id or the event name as the organizer spells it. | |