> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpara.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configure RPC Endpoints

> Set up custom RPC endpoints and chains with Web3 libraries on React Native

export const Card = ({imgUrl, title, description, href, horizontal = false, newTab = false}) => {
  const [isHovered, setIsHovered] = useState(false);
  const handleClick = e => {
    e.preventDefault();
    if (newTab) {
      window.open(href, '_blank', 'noopener,noreferrer');
    } else {
      window.location.href = href;
    }
  };
  return <div className={`not-prose relative my-2 p-[1px] rounded-xl transition-all duration-300 ${isHovered ? 'bg-gradient-to-r from-[#FF4E00] to-[#874AE3]' : 'bg-gray-200'}`} onMouseEnter={() => setIsHovered(true)} onMouseLeave={() => setIsHovered(false)}>
      <a href={href} onClick={handleClick} className={`not-prose flex ${horizontal ? 'flex-row' : 'flex-col'} font-normal h-full bg-white overflow-hidden w-full cursor-pointer rounded-[11px] no-underline`}>
        {imgUrl && <div className={`relative overflow-hidden flex-shrink-0 ${horizontal ? 'w-[30%] rounded-l-[11px]' : 'w-full'}`} onClick={e => e.stopPropagation()}>
            <img src={imgUrl} alt={title} className="w-full h-full object-cover pointer-events-none select-none" draggable="false" />
            <div className="absolute inset-0 pointer-events-none" />
          </div>}
        <div className={`flex-grow px-6 py-5 ${horizontal ? 'w-[70%]' : 'w-full'} flex flex-col ${horizontal && imgUrl ? 'justify-center' : 'justify-start'}`}>
          {title && <h2 className="font-semibold text-base text-gray-800 m-0">{title}</h2>}
          {description && <div className={`font-normal text-gray-500 re leading-6 ${horizontal || !imgUrl ? 'mt-0' : 'mt-1'}`}>
              <p className="m-0 text-xs">{description}</p>
            </div>}
        </div>
      </a>
    </div>;
};

Configure custom RPC endpoints and chains for networks using Web3 libraries. This guide uses public testnet RPCs for demonstration and shows minimal setup with predefined and custom chains where applicable.

<Card title="Setup EVM Libraries First" description="Install and configure Ethers.js or Viem before using EVM operations" href="/v2/react-native/guides/web3-operations/evm/setup-libraries" horizontal />

<Note>
  Wagmi is not available on React Native. Use Ethers.js or Viem for EVM operations.
</Note>

## Configure Custom RPC Endpoints

<Tabs>
  <Tab title="Ethers.js">
    ```typescript theme={null}
    import { ethers } from "ethers";
    import { ParaEthersSigner } from "@getpara/ethers-v6-integration";

    const chainId = 11155111;
    const rpcUrl = "https://ethereum-sepolia-rpc.publicnode.com";

    const provider = new ethers.JsonRpcProvider(rpcUrl, chainId, {
      staticNetwork: true
    });

    const signer = new ParaEthersSigner(para, provider);
    ```
  </Tab>

  <Tab title="Viem">
    ```typescript theme={null}
    import { createPublicClient, http } from "viem";
    import { sepolia } from "viem/chains";
    import { createParaViemClient, createParaViemAccount } from "@getpara/viem-v2-integration";

    const chain = sepolia;
    const transport = http("https://ethereum-sepolia-rpc.publicnode.com");

    const publicClient = createPublicClient({ chain, transport });

    const account = await createParaViemAccount(para);
    const walletClient = createParaViemClient(para, { account, chain, transport });
    ```

    For custom chains:

    ```typescript theme={null}
    const customChain = {
      id: 99999,
      name: "Custom Chain",
      network: "custom",
      nativeCurrency: { name: "Ether", symbol: "ETH", decimals: 18 },
      rpcUrls: {
        default: { http: ["https://custom-rpc.example.com"] },
      },
    };

    const customTransport = http("https://custom-rpc.example.com");

    const customPublicClient = createPublicClient({
      chain: customChain,
      transport: customTransport
    });

    const customAccount = await createParaViemAccount(para);
    const customWalletClient = createParaViemClient(para, {
      account: customAccount,
      chain: customChain,
      transport: customTransport
    });
    ```
  </Tab>
</Tabs>

## Next Steps

<CardGroup cols={3}>
  <Card title="Query Balances" description="Check ETH and token balances across networks" href="/v2/react-native/guides/web3-operations/evm/query-balances" icon="coins" />

  <Card title="Send Tokens" description="Transfer assets on configured networks" href="/v2/react-native/guides/web3-operations/evm/send-tokens" icon="paper-plane" />

  <Card title="Estimate Gas" description="Calculate gas costs for transactions" href="/v2/react-native/guides/web3-operations/evm/estimate-gas" icon="gas-pump" />
</CardGroup>