The event history — the same event objects the stream delivers [read]

The session's history, one event per message: user.message and system.message (with content), agent.message (with parts), user.interrupt, and the turn marks session.status_running, session.status_idle (stop_reason.type is end_turn, retries_exhausted, provider_lost or budget_reached) and session.error. context.input_observed is an authenticated history-only bound context-presence fact, not model usage or task success. agent.reasoning, agent.tool_use, agent.tool_result and agent.status appear on the live stream only, not in history. Oldest-first with an opaque numeric cursor; order=desc reads newest-first and its cursor continues older, so a reader can open on the end of a long session. Every event carries rowId, the number the stream frames carry, so a reader resumes the stream after the newest one it holds. Reconnect = open the stream, list events, dedupe by event id. types[] filters (e.g. types[]=user.message&types[]=agent.message is the transcript view).