export interface AtomicWriteOptions {
    mode?: number;
    signal?: AbortSignal;
}
export declare function mutateFileAtomically(filePath: string, mutate: (contents: string) => string | Promise<string>, options?: AtomicWriteOptions): Promise<void>;
export declare function atomicWrite(filePath: string, data: string, options?: AtomicWriteOptions): Promise<void>;
/** Synchronous variant for sync call sites (e.g. CLI write handlers). Same guard, same
 *  tmp+rename atomicity. */
export declare function atomicWriteSync(filePath: string, data: string): void;