# Connect Reverse ETL Source to LaunchDarkly Segments

This guide takes you through the steps to connect a Reverse ETL source to the LaunchDarkly Segments destination.

## Set up the connection 

{{< warning >}}
**The Reverse ETL feature supports only source-driven pipeline configuration.**

Make sure you have [set up a Reverse ETL source]({{< ref "sources/reverse-etl/_index.md" >}}) and connected it to your LaunchDarkly Segments destination before following the below steps.
{{< /warning >}}

1. [Confirm the connection settings]({{< ref "destinations/reverse-etl-destinations/launchdarkly-segments/setup-guide.md#connection-settings" >}}) for LaunchDarkly Segments destination and click **Continue**.

{{< info >}}
To successfully sync the data, make sure to enter the **Access Token**, **Client Side ID**, **Audience ID**, and **Audience Name** while configuring your LaunchDarkly Segments destination.
{{< /info >}}

2. In the **Where do you want to sync data to?** section, select the **Object**.
3. Set the [Sync mode]({{< ref "data-pipelines/reverse-etl/developer-guides/sync-modes.md" >}}) to specify how RudderStack should sync the data to LaunchDarkly.
4. In **Choose identifier**, specify the warehouse column that RudderStack uses to identify your records.
5. Map your warehouse columns to specific LaunchDarkly fields using the **Map fields** setting.

{{< image src="images/event-stream-destinations/launchdarkly-identifier-map-fields.webp" >}}

## FAQ

#### Why can't I add a Reverse ETL source from the destination page?

The Reverse ETL feature supports only source-driven pipeline configuration. It means that you must configure a Reverse ETL source in RudderStack and then connect it to a new or existing destination. Note that this destination should not be connected to any other source.

See [Reverse ETL FAQ]({{< ref "data-pipelines/reverse-etl/developer-guides/faq.md" >}}) for more information.

#### How do I view the synced segments in LaunchDarkly?

You can view the synced segments in LaunchDarkly in the **Segments** list with the RudderStack logo in the name:

{{< image src="images/event-stream-destinations/view-synced-segments-launchdarkly-1.webp" >}}

Click the segment to view the sync details:

{{< image src="images/event-stream-destinations/view-synced-segments-launchdarkly-2.webp" >}}