import { ApiPromise } from "@polkadot/api";
/**
 * @category PolkaBTC Bridge
 */
export interface SystemAPI {
    /**
     * @returns The current block number being processed.
     */
    getCurrentBlockNumber(): Promise<number>;
    /**
     * @returns The current active block number being processed.
     */
    getCurrentActiveBlockNumber(): Promise<number>;
}
export declare class DefaultSystemAPI implements SystemAPI {
    private api;
    constructor(api: ApiPromise);
    getCurrentBlockNumber(): Promise<number>;
    getCurrentActiveBlockNumber(): Promise<number>;
}