/**
 * Channel adapters — the pluggable cross-context message transport beneath the
 * RPC bridge. The same protocol/handshake/RPC layers run over either topology;
 * only the `Channel` implementation differs.
 */
import { ApnaMessage } from '../protocol';
/**
 * A bidirectional, per-instance message channel. Implementations hold no
 * module-global state, so many can coexist (one per running mini-app).
 */
export interface Channel {
    /** Post a protocol message to the peer. */
    send(message: ApnaMessage): void;
    /** Register an inbound-message handler. Returns an unsubscribe function. */
    onMessage(handler: (message: ApnaMessage) => void): () => void;
    /** Resolves once the channel can carry messages. */
    ready(): Promise<void>;
    /** Tear down listeners and release the channel. */
    dispose(): void;
}
export declare type ChannelKind = 'iframe' | 'extension';
export interface DetectChannelOptions {
    /** Explicit channel — used as-is, bypassing detection. */
    channel?: Channel;
    /** Force a channel kind instead of auto-detecting. */
    kind?: ChannelKind;
    /** Expected peer origin, forwarded to the constructed channel. */
    targetOrigin?: string;
}
/**
 * Pick the right `Channel` for the mini-app's runtime context:
 * - inside an iframe (`window.parent !== window`) → `IframeChannel`
 * - a host-extension marker is present on `window` → `ExtensionChannel`
 * - otherwise throw — pass an explicit `channel` or `kind` to override.
 *
 * This is the client (mini-app) entry point. The host constructs its
 * per-iframe `IframeChannel` directly.
 */
export declare function detectChannel(options?: DetectChannelOptions): Channel;
export { IframeChannel } from './iframe';
export type { IframeChannelOptions } from './iframe';
export { ExtensionChannel, RELAY_TO_HOST, RELAY_TO_APP } from './extension';
export type { ExtensionChannelOptions } from './extension';