import { type DurableSessionState } from "#execution/durable-session-store.js";
import type { UnstampedMessageStreamEvent } from "#protocol/message.js";
/** Emits an agent invocation event on the parent stream. */
export declare function emitSubagentEventStep(input: {
    readonly event: UnstampedMessageStreamEvent;
    readonly sessionWritable: WritableStream<Uint8Array>;
    readonly serializedContext: Record<string, unknown>;
    readonly sessionState: DurableSessionState;
}): Promise<{
    readonly serializedContext: Record<string, unknown>;
}>;