/**
 * The INNER half of an embedded Vendo surface (blueprint §12.3) — every
 * surface that renders inside a host-owned iframe owes the host the same two
 * behaviours, so they share this module rather than each keeping a copy of the
 * protocol.
 *
 * Both jobs are RECEIVING or REPORTING, never negotiating:
 *
 *  - `applyThemeVars` receives the host's brand tokens. Only `--vendo-*` custom
 *    properties may cross into the surface (06 §5).
 *  - `startFrameProtocol` reports the surface's natural content height to the
 *    embedding frame, then announces `booted`.
 *
 * THE HOST'S BOUNDS WIN (founder ruling 2026-08-04). The host sized the slot
 * when it embedded Vendo; that is a constraint the app lives inside, never
 * overrides. This module only ever REPORTS a natural height — it holds no code
 * that sets or negotiates its own size against the host, and must never grow
 * any. An app taller than the host allows scrolls inside its own frame; it never
 * pushes the host's layout. The clamp is the host's, and so is the min/max the
 * host configured.
 */
import type { Json, ToolOutcome } from "../core/index.js";
/** Post one message to the embedding host. Every message is stamped `vendo: true`
 *  — that stamp is how the host tells a Vendo surface's messages from any other
 *  frame's, so it is part of the protocol and not an implementation detail. */
export declare function postToHost(message: Record<string, unknown>): void;
/** Host brand tokens: only --vendo-* custom properties may cross into an
    embedded surface, so generated code styled with the theme variables matches
    the host (06 §5). */
export declare function applyThemeVars(vars: unknown): void;
/**
 * THE ONE DOOR to host data (FINAL SPEC v1). A sealed surface has an opaque
 * origin and no network at all, so this is the only thing it can reach — and
 * what it reaches is the host's guarded tool door, run with the VIEWER's own
 * permissions. Nothing here decides what is allowed; the guard does, and a call
 * the viewer may not make comes back as a refused outcome like any other.
 */
export declare function callHost(ref: string, args?: Json): Promise<ToolOutcome>;
/**
 * Start the frame protocol on `mount`: normalize viewport-relative block
 * constraints, report the content height on every content change, and announce
 * `booted` once the observers are live.
 *
 * Messages out: `{ vendo: true, kind: "resize", height }`,
 * `{ vendo: true, kind: "booted" }`, and one `{ kind: "call" }` per
 * {@link callHost}. In: `theme` and `result`.
 */
export declare function startFrameProtocol(mount: HTMLElement, post?: typeof postToHost): void;