import { RpcSource } from './index.js';
/**
 * Retrieves the pending queue index from the L1 message queue contract.
 *
 * @param rpc - The RPC source to use for querying the blockchain.
 * @param l1MessageQueueProxyAddress - The address of the L1 message queue proxy contract.
 * @returns A promise that resolves to the pending queue index as a bigint.
 */
export declare function getPendingQueueIndex(rpc: RpcSource, l1MessageQueueProxyAddress: string): Promise<bigint>;