Get thread summary
Returns the incremental summary generated from messages in the thread. Returns 404 if no summary exists for the thread.
LastSummarizedAt is the wall-clock timestamp of the most recent summary update. This is an ingestion-time watermark; for the event-time recency of the summary’s content, use LastSummarizedEpisodeValidAt instead.
LastSummarizedEpisodeValidAt is the maximum episode reference time (valid_at) covered by the most recent summary. Use this when answering “how recent is this summary’s content in event-time?”.
ThreadID is the ID of the thread this summary belongs to. When a thread was created without an explicit thread_id, this field falls back to the thread’s UUID. Clients should treat it as an opaque identifier.