OptionalenabledExplicit enablement for this session; when set it wins over the model's default. undefined means "no explicit choice".
OptionaltokenInput-token threshold for this session; when set it wins over the model's default. undefined preserves the provider default.
Per-session/per-request server-side compaction settings, carried verbatim from the chat session's common settings to the request. Kept as an object so further parameters can be added later.