Function session_history 

pub fn session_history(
    config_dir: &Path,
    session_id: &str,
    cwd: &str,
) -> ConversationHistory

The messages a session’s transcript holds and the compactions it records. The same read the spawn performs, available for a session that is already running.

A view is not the only way to a running session’s conversation any more. The socket’s transport holds one it is seeded with by the session task, so this read is for a consumer that has no such copy - a view attaching late, or a fixture.