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# Manage Chains

## Overview

Chain Actions manage the network selected by the wallet. Add a Chain when the wallet does not know
it, then switch to it before sending requests against that network.

## Recipes

These recipes assume you have [connected a wallet](/docs/guides/wallets/connect).

### Add and Switch Chains

Use [`chains.add`](/docs/actions/wallet/chains/add) when the wallet does not know the Chain, then
[`chains.switch`](/docs/actions/wallet/chains/switch) to select it.

:::code-group
```ts twoslash [example.ts]
import { optimism } from 'viem/chains'
import { client } from './viem.config'

await client.chains.add({ chain: optimism }) // [!code focus]
await client.chains.switch({ id: optimism.id }) // [!code focus]
```

```ts twoslash [viem.config.ts] filename="viem.config.ts"
// [!include ~/snippets/docs/wallet.config.ts:setup]
```
:::

## Best Practices

### Handle Chain Changes

Recreate or update Chain-bound application state after a successful switch. Cached addresses,
tokens, contracts, and fee assumptions may no longer apply.

## See More

<Cards>
  <Card icon="lucide:plug" title="Connect a Wallet" description="Establish the provider connection before managing its network." to="/docs/guides/wallets/connect" />

  <Card icon="lucide:network" title="Chains" description="Create and extend typed Chain definitions." to="/docs/chains" />
</Cards>