import { Logger } from '@verdaccio/types';
/**
 * Detect a legacy callback-based storage plugin. The new contract's `get()`
 * takes no arguments (returns a promise); the legacy `get(cb)` declares a
 * trailing callback, and `add(name, cb)` takes two. Arity is a stable signal
 * here because both contracts are frozen.
 */
export declare function isLegacyStoragePlugin(plugin: any): boolean;
/**
 * Wrap a legacy callback storage plugin in the promise contract expected by
 * `@verdaccio/store`. Token methods are exposed only when the legacy plugin
 * implements them (store already guards their absence with SERVICE_UNAVAILABLE).
 */
export declare function wrapLegacyStoragePlugin(plugin: any, logger: Logger): any;