/**
 * npm registry freshness for the running CLI (npx cache often sticks on old builds).
 */
export declare function compareSemver(a: string, b: string): number;
/** True when `candidate` is strictly newer than `current`. */
export declare function isSemverNewer(candidate: string, current: string): boolean;
/**
 * Fetch `latest` from the npm registry. Returns null on timeout/network/parse errors.
 */
export declare function fetchNpmLatestVersion(packageName: string, timeoutMs?: number): Promise<string | null>;
export interface CliFreshness {
    running: string;
    latest: string | null;
    stale: boolean;
}
export declare function checkCliFreshness(runningVersion: string, packageName?: string): Promise<CliFreshness>;
/**
 * `npx pkg@latest` keeps the extracted tree under `~/.npm/_npx` keyed by the
 * spec string, so a later publish still runs the old binary. Re-run the
 * registry version (a new cache key) with prefer-online. Do not wipe the
 * whole npm cache. `SVS_REEXEC=1` stops a loop.
 */
export declare function reexecIfRegistryIsNewer(running: string, argv: string[]): Promise<void>;