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

# useChain

> Hook for retrieving chain configuration information

## Import

```tsx theme={null}
import { useChain } from '@0xsequence/connect'
```

## Usage

```tsx theme={null}
import { useChain } from '@0xsequence/connect'

function App() {
  // Get current chain configuration
  const currentChain = useChain()
  
  // Get configuration for a specific chain (e.g., Ethereum Mainnet)
  const ethereumChain = useChain(1)
  
  return (
    <div>
      <h2>Current Chain</h2>
      {currentChain && (
        <div>
          <p>Name: {currentChain.name}</p>
          <p>Chain ID: {currentChain.id}</p>
          <p>Network: {currentChain.network}</p>
          <p>Native Currency: {currentChain.nativeCurrency.symbol}</p>
        </div>
      )}
      
      <h2>Ethereum Mainnet</h2>
      {ethereumChain && (
        <div>
          <p>Name: {ethereumChain.name}</p>
          <p>Chain ID: {ethereumChain.id}</p>
          <p>Network: {ethereumChain.network}</p>
          <p>Native Currency: {ethereumChain.nativeCurrency.symbol}</p>
        </div>
      )}
    </div>
  )
}
```

## Parameters

| Parameter | Type                  | Description                                                                                                              |
| --------- | --------------------- | ------------------------------------------------------------------------------------------------------------------------ |
| `chainId` | `number \| undefined` | Optional chain ID to get configuration for a specific chain. If not provided, returns the current chain's configuration. |

## Return Type: `Chain | undefined`

The hook returns a `Chain` object from wagmi's chain configurations or `undefined` if the chain is not found.

```tsx theme={null}
interface Chain {
  id: number
  name: string
  network: string
  nativeCurrency: {
    name: string
    symbol: string
    decimals: number
  }
  rpcUrls: {
    default: {
      http: string[]
      webSocket?: string[]
    }
    public: {
      http: string[]
      webSocket?: string[]
    }
  }
  blockExplorers?: {
    default: {
      name: string
      url: string
    }
  }
  // ... other chain-specific properties
}
```

### Properties

#### id

`number`

The unique identifier of the blockchain network.

#### name

`string`

The human-readable name of the blockchain network.

#### network

`string`

The network identifier string.

#### nativeCurrency

`object`

Information about the chain's native currency.

```tsx theme={null}
{
  name: string      // Full name of the currency
  symbol: string    // Currency symbol
  decimals: number  // Number of decimal places
}
```

#### rpcUrls

`object`

URLs for connecting to the network's RPC endpoints.

#### blockExplorers

`object | undefined`

Information about block explorers for the chain.

## Notes

This hook provides easy access to chain configuration information from wagmi's chain configurations. It's particularly useful when you need to:

* Access details about the currently connected chain
* Get configuration for a specific chain by ID
* Retrieve chain-specific information like:
  * Network details
  * Native currency information
  * RPC endpoints
  * Block explorer URLs

The hook is commonly used in conjunction with other Sequence hooks when working with transactions, indexer clients, or network-specific features.