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

# useRelayChains

> Fetch all relay supported chains

## Parameters

| Parameter        | Description                                                                                                                                                                                   | Required |
| ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------- |
| **baseApiUrl**   | Base api url for the relay api, defaults to [https://api.relay.link](https://api.relay.link) but can also be configured to [https://api.testnets.relay.link](https://api.testnets.relay.link) | ❌        |
| **options**      | Query parameters that map directly to the [chains api](/references/api/get-chains)                                                                                                            | ❌        |
| **queryOptions** | Tanstack query options. Refer to the [Tanstack](https://tanstack.com/query/latest/docs/framework/react/guides/query-options) docs.                                                            | ❌        |

## Return Data

The hook returns an object with the base [Tanstack Query response](https://tanstack.com/query/v5/docs/framework/react/reference/useQuery). The data property maps to the object returned in the aforementioned [chains api](/references/api/get-chains). You'll also get back chains (an array of RelayChains) and viemChains (an array of viem compatible chains). You can use the viem chains in your wagmi config.

## Usage

<CodeGroup>
  ```typescript theme={null}
  import { useRelayChains } from '@relayprotocol/relay-kit-hooks'

  const { chains, viemChains } = useRelayChains()

  ```
</CodeGroup>

## Query Function

```typescript theme={null}
import { queryRelayChains } from '@relayprotocol/relay-kit-hooks'

queryRelayChains()

```