/**
 * The signed-in user's TORUK access token, handed to the widget by the host page.
 *
 * A host whose visitors are already signed in to TORUK (directly, or through an
 * app that logs them in with TORUK) passes the user's access token here and the
 * widget sends it as `Authorization: Bearer` on every runtime request — config,
 * predictions, sessions, artifacts. CORE then identifies and authorizes that
 * user, and everything the conversation creates belongs to them.
 *
 * A function is called on every request, so a host that rotates tokens returns
 * the current one and nothing goes stale mid-conversation. Returning an empty
 * value sends the request without the header.
 */
export type WidgetAccessToken = string | (() => string | null | undefined | Promise<string | null | undefined>);
export type WidgetRequestHook = (request: RequestInit) => Promise<void>;
/**
 * Compose the host's `onRequest` hook with the bearer header. The header is set
 * first, so a host hook still sees and may override it; whatever `headers` shape
 * the request carried is normalized to a `Headers` instance the transports accept.
 */
export declare const withAccessToken: (accessToken: WidgetAccessToken | undefined, onRequest?: WidgetRequestHook) => WidgetRequestHook | undefined;