/**
 * Visitor identity + environment capture.
 *
 * `visitorId` is an opaque UUID persisted in `localStorage.__hfe_visitor_id__`
 * (per-origin, per-browser). It stitches a user's activity across pageloads,
 * refreshes, and tabs so the daemon can build a coherent user journey.
 *
 * Privacy: anonymous by default. No canvas / WebGL / AudioContext
 * fingerprinting. The app may pass `userId` via `HarnessaScript userId=…`
 * which the daemon attaches to `VisitorMeta.userId` — that field is only
 * meaningful when the host app explicitly opts in.
 */
import type { VisitorEnv } from '@harnessa-fe/protocol';
/** Read or lazily create the visitorId. localStorage scope = per-origin. */
export declare function getOrCreateVisitorId(): string;
/**
 * Same-origin iframe child inherits the parent's visitorId so the journey
 * stitches across micro-frontends. Cross-origin children fall back to their
 * own (a different visitorId — expected, browsers isolate localStorage).
 */
export declare function tryInheritVisitorFromParent(): string | undefined;
/**
 * Snapshot the browser environment for this pageload. Cheap (all sync
 * reads); safe to call on every hello.
 */
export declare function collectEnv(): VisitorEnv;
/** Expose to same-origin iframes; called by client.ts after resolving id. */
export declare function publishVisitorIdToWindow(id: string): void;