/**
 * Napplet NAP storage shim entrypoint.
 *
 * @module
 */
interface NappletStorageApi {
    getItem(key: string): Promise<string | null>;
    setItem(key: string, value: string): Promise<void>;
    removeItem(key: string): Promise<void>;
    keys(): Promise<string[]>;
    instance: {
        getItem(key: string): Promise<string | null>;
        setItem(key: string, value: string): Promise<void>;
        removeItem(key: string): Promise<void>;
        keys(): Promise<string[]>;
    };
}
/**
 * Async localStorage-like state API for sandboxed napplets.
 *
 * Routes all state operations through the shell's state proxy via postMessage.
 * Each napplet's state is namespaced by its identity -- napplets cannot read each other's data.
 * A per-napplet 512 KB quota is enforced by the shell.
 *
 * Top-level methods use the default `"shared"` scope and emit no `scope` field
 * on the wire. The `instance` sub-object is sugar that sets `scope: "instance"`
 * for per-instance storage (NAP-STORAGE).
 */
declare const nappletStorage: NappletStorageApi;
/**
 * Install the storage response listener.
 * Called by @napplet/shim during initialization.
 *
 * @returns cleanup function that removes the listener
 */
declare function installStorageShim(): () => void;

export { installStorageShim, nappletStorage };