import type { Express } from 'express';
/**
 * Profile-independent handoff injection.
 *
 * The CDP navigation-watcher only sees tabs inside the Chrome instance
 * SLICC launched (isolated profile keyed by port); similarly the
 * extension's webRequest observer only fires inside the profile where it
 * is installed. External tools (e.g. the slicc-handoff helper) post here
 * so a handoff reaches the cone regardless of which browser profile the
 * user is currently driving.
 *
 * The payload mirrors the parsed RFC 8288 `Link` form used by the
 * observers: `verb` ∈ {handoff, upskill}, `target` is the resolved URL,
 * `instruction` is optional free-form prose (handoff verb).
 */
export interface HandoffPayload {
    verb?: unknown;
    target?: unknown;
    instruction?: unknown;
    url?: unknown;
    title?: unknown;
    branch?: unknown;
    path?: unknown;
    sliccHeader?: unknown;
}
export interface NavigateEvent {
    type: 'navigate_event';
    verb: 'handoff' | 'upskill';
    target: string;
    instruction?: string;
    url: string;
    title?: string;
    branch?: string;
    path?: string;
    timestamp: string;
}
export interface HandoffRouteDeps {
    broadcastLickEvent(event: unknown): void;
}
/**
 * Validate an inbound handoff payload. Returns an error message when the
 * payload is malformed, or `null` when it is well-formed and ready to be
 * turned into a navigate event. Pure — no I/O.
 */
export declare function validateHandoffPayload(payload: HandoffPayload): string | null;
/** Build the navigate event broadcast to the browser. Assumes a valid payload. */
export declare function buildNavigateEvent(payload: HandoffPayload): NavigateEvent;
export declare function registerHandoffRoute(app: Express, deps: HandoffRouteDeps): void;