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

# Client Configuration

> Configure AutoMQ clients with zone identifiers and Follower Fetching to eliminate cross-availability-zone data transfer costs.

## Set Zone Identifier

In addition to configuring client Zone identification rules on the server-side ([Server-side Configuration▸](/automq-cloud/eliminate-inter-zone-traffics/broker-configuration)), AutoMQ also supports clients specifying Zone information. This is done by appending `automq_az=$zoneId` to the `client.id` to identify the client's Zone. The `client.id` format is as follows:

```text theme={null}
client.id=automq_az=$zoneId&existing-client-id
```

<Tip>
  On AWS, it is recommended to use the [zoneId](https://docs.aws.amazon.com/ram/latest/userguide/working-with-az-ids.html) instead of the zoneName, as the zoneId is consistent across all accounts.
</Tip>

## Follower Fetching

Besides setting the Zone identifier via `client.id`, clients with a version greater than 2.4.0 can also use the [KIP-392: Allow consumers to fetch from closest replica](https://cwiki.apache.org/confluence/display/KAFKA/KIP-392%3A+Allow+consumers+to+fetch+from+closest+replica) feature to configure consumption Zone affinity. The configuration is as follows:

```text theme={null}
client.rack=$zoneId
```