updatedAt property
UpdatedAt is the session's last-activity clock, same format. It moves on a write to the row — a status, a title, a re-dispatch — AND on every appended turn, because the append bumps it in the same transaction. The list is ordered on CreatedAt, so this is the field that says whether a session is still saying anything.
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
String? updatedAt;