export type ConversationTurnQueueStatus = "failed" | "queued" | "running";
export type ConversationTurnQueueItem<Input> = {
    error?: unknown;
    id: string;
    input: Input;
    status: ConversationTurnQueueStatus;
};
export type ConversationTurnQueueSnapshot<Input> = {
    items: ReadonlyArray<ConversationTurnQueueItem<Input>>;
    running: boolean;
};
export type ConversationTurnQueueOptions<Input> = {
    execute: (input: Input, context: {
        id: string;
        signal: AbortSignal;
    }) => Promise<void>;
    maxSize?: number;
    onError?: (error: unknown, item: ConversationTurnQueueItem<Input>) => void;
};
export declare class ConversationTurnQueueFullError extends Error {
    constructor(maxSize: number);
}
/**
 * Serializes turns for one conversation.
 *
 * The queue is transport-agnostic: WebSocket chat, REST/SSE applications, and
 * durable adapters can all provide their own `execute` boundary. Failed turns
 * remain visible and stop the queue until the host retries or removes them, so
 * a later follow-up can never silently overtake a failed earlier message.
 */
export declare const createConversationTurnQueue: <Input>(options: ConversationTurnQueueOptions<Input>) => {
    cancel: (input?: {
        clearPending?: boolean;
    }) => void;
    enqueue: (input: Input, id?: string) => string;
    getSnapshot: () => ConversationTurnQueueSnapshot<Input>;
    remove: (id: string) => boolean;
    retry: (id: string) => boolean;
    subscribe: (listener: (snapshot: ConversationTurnQueueSnapshot<Input>) => void) => () => boolean;
};