[Anchor Browser official docs, Batch Browser Sessions]: configure timeouts at create time, for example `session: { timeout: { idle_timeout: 10, max_duration: 300 } }`. Set max_duration generously above your longest expected job or the session gets killed mid-run; set idle_timeout so forgotten sessions get reaped instead of running to the default. The shape is the same for sync, async, and batch creates.

Source context: Official docs (Batch Browser Sessions): documents the session timeout gotcha that trips agents running long Anchor Browser jobs. Sessions accept `session.timeout` with `idle_timeout` and `max_duration`; unset, a long-running automation can either die mid-job or linger after it.