Claude Code System Prompts

Protocol capabilities this CLI supports, so SDK consumers can feature-detect instead of version-sniffing. Open set — ignore unknown values; check each capability for exactly the behavior you use. 'interrupt_receipt_v1' = the interrupt control_response success payload carries still_queued (uuids of async user messages that survive the interrupt). 'interrupt_cancel_queued_v1' = the interrupt control_request honors cancel_queued:true (queued and pending-dispatch commands are cancelled alongside the abort, listed on the response's cancelled field; still_queued is then empty — including any uuid that was mid-fold at the interrupt instant, since this request also aborts and the fold never delivers it — except that a client driving a hosted session lists there what it can no longer recall: a send already in flight to that session, or the first prompt the session was created with). 'queued_notifications' = the CLI accepts inbound queued_notification stream messages and drains them via ReadNotifications (the cloud session backend reads this from the persisted init event to decide whether it may send them). Absent on older CLIs.