/**
 * Hot-path perf writers — append-only NDJSON spool, no SQLite.
 *
 * Loaded from the CLI root `postAction` and from `events.ts` timing helpers.
 * Must stay free of `../sqlite.js` so ordinary commands never load node:sqlite
 * (which emits ExperimentalWarning on stderr).
 */
import type { PerfSample } from './types.js';
export type { PerfSample } from './types.js';
/** Test seam — pair with db._resetPerfDbForTest. */
export declare function _resetPerfSpoolForTest(spoolPath?: string | null): void;
export declare function resolveSpoolPath(): string;
/** Short session id: first 8 chars (sessions.short_id shape). */
export declare function shortSessionId(sessionId: string | undefined | null): string | undefined;
/**
 * Append one sample to the spool. Never throws. Never opens SQLite.
 */
export declare function recordSample(sample: PerfSample): void;
