import { ServiceHandler } from "@blockprotocol/core";
import { EmbedderExternalApiMessageCallbacks, EmbedderExternalApiMessages } from "./types.js";
/**
 * Creates a handler for the externalApi service for the embedder.
 * Register callbacks in the constructor or afterwards using the 'on' method to
 * react to messages from the block. Call the relevant methods to send messages
 * to the block.
 */
export declare class ExternalApiEmbedderHandler extends ServiceHandler implements EmbedderExternalApiMessages {
    constructor({ callbacks, element, }: {
        callbacks?: Partial<EmbedderExternalApiMessageCallbacks>;
        element?: HTMLElement | null;
    });
    /**
     * Call the provided function when the named message is received, passing the
     * data/errors object from the message. If the named message expects a
     * response, the callback should provide the expected data/errors object as
     * the return.
     * @param messageName the message name to listen for
     * @param handlerFunction the function to call when the message is received,
     *   with the message data / errors
     */
    on<K extends keyof EmbedderExternalApiMessageCallbacks>(this: ExternalApiEmbedderHandler, messageName: K, handlerFunction: NonNullable<EmbedderExternalApiMessageCallbacks[K]>): void;
    getInitPayload(this: ExternalApiEmbedderHandler): Record<string, any>;
}