Suggested state
start_thread, send_message, and get_thread. Keep authentication and payment in their dedicated operations. Route from typed requests and operation states; do not infer valid transitions from elapsed time or model prose.
Checkpoint before and after each write so retries can reuse the same idempotencyKey and avoid duplicate work.
Suggested nodes
Never route directly from model sentiment such as “looks done.” Route from Darwin’s structured response and checkpoint the result.