/** A server-resolved field operation. Pass as a field value in `set`/`setMany`. */
export type FieldOperation = {
    operation: 'increment';
    value: number;
} | {
    operation: 'time';
    value: 'now';
};
/**
 * Atomically add `value` to a numeric field when the write commits, server-side.
 * Use a negative `value` to decrement. The field starts from 0 if the document
 * (or field) does not exist yet. Concurrent increments are race-free.
 *
 *   await set("counters/likes", { n: increment(1) });
 *   await set("scores/p1", { points: increment(-5) });
 */
export declare function increment(value: number): FieldOperation;
/**
 * Stamp a field with the server's clock (Unix seconds) when the write commits —
 * the trustworthy "when did this happen" you can't get from a client clock.
 *
 *   await set("posts/p1", { createdAt: serverTimestamp() });
 */
export declare function serverTimestamp(): FieldOperation;