export interface UpdateCache {
    checkedAt: number;
    latest: string | null;
}
export declare const readUpdateCache: () => UpdateCache | null;
export declare const updateHint: () => string | null;
export declare const fetchLatestVersion: (timeoutMs: number, url?: string) => Promise<string | null>;
export interface RefreshDeps {
    now?: () => number;
    read?: () => UpdateCache | null;
    fetch?: () => Promise<string | null>;
    write?: (latest: string | null, now: number) => void;
}
export declare const refreshUpdateCache: (deps?: RefreshDeps) => Promise<void>;