Trace

query_metadata describes why this trace matched the query, including sem_filter_score when a semantic filter is used. Returned automatically, or null when unavailable.

root_run is the trace's root run. Which properties are populated is controlled by selects in the request.

trace_aggregates carries trace-wide aggregate metrics. Omitted when no aggregate field was selected, or null (then later filled) on the streaming wire while the aggregate values are still being computed.