/**
 * Artifact Store for Railgun Circuit Files
 *
 * Stores circuit artifacts (wasm, zkey, vkey) persistently.
 * - Browser: Uses IndexedDB for persistent storage
 * - Node.js: Uses file system for persistent storage
 *
 * Total size: ~9.5MB (downloaded once, cached forever)
 *
 * This enables client-side ZK proof generation without re-downloading
 * circuit files on every session.
 */
type GetArtifact = (path: string) => Promise<string | Buffer | null>;
type StoreArtifact = (dir: string, path: string, item: string | Uint8Array) => Promise<void>;
type ArtifactExists = (path: string) => Promise<boolean>;
declare class ArtifactStore {
    get: GetArtifact;
    store: StoreArtifact;
    exists: ArtifactExists;
    constructor(get: GetArtifact, store: StoreArtifact, exists: ArtifactExists);
}
/**
 * Creates an artifact store for Railgun circuits
 * Automatically uses the right storage backend based on environment:
 * - Browser: IndexedDB
 * - Node.js: File system
 *
 * @returns ArtifactStore instance
 */
export declare function createIndexedDBArtifactStore(): Promise<ArtifactStore>;
/**
 * Clears all cached artifacts
 * - Browser: Deletes IndexedDB
 * - Node.js: Deletes cache directory
 */
export declare function clearArtifactCache(): Promise<void>;
/**
 * Checks if artifacts are already cached
 * Can be used to show different UI for first-time vs returning users
 */
export declare function areArtifactsCached(): Promise<boolean>;
export {};