Support fetching ETH balances for multiple wallet addresses in useBalance

[fsolla]

Hi wagmi team 👋

I’ve been building with wagmi on a project called Mycelia, where users can connect and monitor multiple wallets. One use case is displaying the total ETH balance across all their wallets. To support this, I built a custom hook that fetches ETH balances for multiple addresses in parallel. Similar to useBalance, but accepting an array of addresses.

This made me wonder: what if useBalance could also accept an addresses array in addition to a single address?

Instead of creating a separate hook like useBalances, it might feel more natural to allow:

const { data, isLoading } = useBalance({
  address: ['0x123...', '0xabc...', '0xdef...'],
});

Only when and array of addresses is passed, the return value could follow the current useBalance structure, but with arrays for fields that vary by address:

{
  decimals: number;
  symbol: string;
  value: (bigint | undefined)[];
  formatted: (string | undefined)[];
}

Each index would match the corresponding input address, and developers could sum the values themselves if needed.

Why this could be useful:

• Better support for multi-wallet interfaces
• Reduces boilerplate when displaying balances for multiple addresses
• Keeps the developer ergonomics consistent with wagmi's existing APIs

I'm happy to help with the implementation if the idea makes sense for wagmi’s direction.

Would love to hear your thoughts on this!
Thanks for your incredible work, wagmi has been a joy to work with ✨