/** A checkpoint taken before an internal manifest write, never an expiry override. */
export interface ArtifactActivity {
    last_changed_at: string;
    root_entries_sha256: string;
}
export declare function validArtifactActivity(value: unknown): value is ArtifactActivity;
export declare function artifactRootEntries(path: string): string;
/** Metadata writes change both the manifest and its parent directory timestamps.
 * Keep the prior root activity while its payload entries match the checkpoint.
 * A root deletion or rename changes that fingerprint; nested changes retain
 * their ordinary filesystem timestamps. Symlinks are inspected, never followed.
 */
export declare function readArtifactActivity(path: string, now: Date, previous?: ArtifactActivity): ArtifactActivity;
//# sourceMappingURL=activity.d.ts.map