import { Store } from '../types';
export interface SyncTransport {
    send(message: any): void;
    onReceive(handler: (message: any) => void): () => void;
    close?(): void;
}
export type ConflictResolver<T> = (local: T, remote: Partial<T>) => Partial<T>;
export interface SyncOptions<T> {
    transport: SyncTransport | (() => SyncTransport);
    filter?: (state: T) => any;
    resolve?: 'remote-wins' | 'local-wins' | 'merge' | ConflictResolver<T>;
    instanceId?: string;
    accept?: (message: any) => boolean;
}
export declare function syncMiddleware<T>(options: SyncOptions<T>): (store: Store<T>) => Store<T>;
export declare function broadcastChannelTransport(channelName: string): SyncTransport;
export declare function storageEventTransport(storageKey: string, storage?: Storage): SyncTransport;
export declare function webSocketTransport(url: string, protocols?: string | string[]): SyncTransport;