***

## title: fallback

You can use the `fallback` provider to add more resilience to your application.

A fallback will attempt to use the first client, and if it fails, it will try the second client, and so on.

<Tip>
  You can nest fallbacks inside of other fallbacks.
</Tip>

```baml BAML
client<llm> SuperDuperClient {
  provider fallback
  options {
    strategy [
      ClientA
      ClientB
      ClientC
    ]
  }
}
```

## Options

<ParamField path="strategy" type="List[string]" required>
  The list of client names to try in order. Cannot be empty.
</ParamField>

## retry\_policy

Like any other client, you can specify a retry policy for the fallback client. See [retry\_policy](retry-policy) for more information.

The retry policy will test the fallback itself, after the entire strategy has failed.

```baml BAML
client<llm> SuperDuperClient {
  provider fallback
  retry_policy MyRetryPolicy
  options {
    strategy [
      ClientA
      ClientB
      ClientC
    ]
  }
}
```

## Nesting multiple fallbacks

You can nest multiple fallbacks inside of each other. The fallbacks will just chain as you would expect.

```baml BAML
client<llm> SuperDuperClient {
  provider fallback
  options {
    strategy [
      ClientA
      ClientB
      ClientC
    ]
  }
}

client<llm> MegaClient {
  provider fallback
  options {
    strategy [
      SuperDuperClient
      ClientD
    ]
  }
}
```