/**
 *  Fetches contract ABI from etherscan, if one exists.
 * @param address - Contract address
 * @returns ABI|null
 */
export declare function lookupContractAbi(address: string): Promise<{
    constant: boolean;
    inputs: {
        name: string;
        type: string;
    }[];
    name: string;
    outputs: {
        name: string;
        type: string;
    }[];
    payable: boolean;
    stateMutability: string;
    type: string;
}[] | null>;