/**
 * Namespaced storage for organizing data
 */
export declare class NamespacedStorage {
    private prefix;
    private storage;
    constructor(storage: any, namespace: string);
    private getIndex;
    private saveToIndex;
    private removeFromIndex;
    /**
     * Set item in this namespace
     */
    setItem(key: string, value: string): Promise<void>;
    /**
     * Set item with expiry in this namespace
     */
    setItemWithExpiry(key: string, value: string, options: {
        expiresIn?: number;
        expiresAt?: Date;
    }): Promise<void>;
    /**
     * Get item from this namespace
     */
    getItem(key: string): Promise<string | null>;
    /**
     * Remove item from this namespace
     */
    removeItem(key: string): Promise<void>;
    /**
     * Check if item exists in this namespace
     */
    hasItem(key: string): Promise<boolean>;
    /**
     * Clear all items in this namespace
     */
    clearNamespace(): Promise<void>;
    /**
     * Get all keys in this namespace
     */
    keys(): Promise<string[]>;
}