/**
 * Returns a Katana Testnet chain definition compatible with viem's client setup.
 *
 * @param katanaApiKey - Optional API key for the RPC endpoint.
 * @returns A `Chain` object for the Katana Testnet.
 */
export declare const katanaTestnet: (katanaApiKey?: string) => {
    blockExplorers: {
        readonly default: {
            readonly name: "Katana Explorer";
            readonly url: "https://explorer.tatara.katana.network/";
            readonly apiUrl: "";
        };
    };
    blockTime?: number | undefined | undefined;
    contracts: {
        readonly ensRegistry: {
            readonly address: "0x0000000000000000000000000000000000000000";
        };
        readonly ensUniversalResolver: {
            readonly address: "0x0000000000000000000000000000000000000000";
            readonly blockCreated: 0;
        };
        readonly multicall3: {
            readonly address: "0x0000000000000000000000000000000000000000";
            readonly blockCreated: 0;
        };
    };
    ensTlds?: readonly string[] | undefined;
    id: 129399;
    name: "Katana Testnet";
    nativeCurrency: {
        readonly name: "Ether";
        readonly symbol: "ETH";
        readonly decimals: 18;
    };
    rpcUrls: {
        readonly default: {
            readonly http: readonly [`https://rpc.tatara.katanarpc.com/${string}`];
        };
    };
    sourceId?: number | undefined | undefined;
    testnet?: boolean | undefined | undefined;
    custom?: Record<string, unknown> | undefined;
    fees?: import("viem").ChainFees<undefined> | undefined;
    formatters?: undefined;
    serializers?: import("viem").ChainSerializers<undefined, import("viem").TransactionSerializable> | undefined;
};