import type { UnstampedMessageStreamEvent } from "#protocol/message.js";
/** Hides a scheduled background launch while preserving its turn boundary. */
export declare function scheduledLaunchDeliveryEvent(event: UnstampedMessageStreamEvent, input: {
    readonly isFirstTurn: boolean;
    readonly isScheduled: boolean;
    readonly taskPhase: "none" | "initiating" | "pending" | "settled" | undefined;
}): UnstampedMessageStreamEvent | undefined;