> ## Documentation Index
> Fetch the complete documentation index at: https://launchdarkly-preview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Service endpoint configuration

> This topic explains how to configure LaunchDarkly SDKs to connect to alternate service endpoints. Typically this is only required for customers working with the LaunchDarkly federal instance.

> For the complete documentation index, see [llms.txt](/llms.txt). For the full documentation snapshot, see [llms-full.txt](/llms-full.txt).

## Overview

This topic explains how to configure LaunchDarkly SDKs to connect to alternate service endpoints.

Each SDK connects to several LaunchDarkly web services. These include services for getting feature flag data using streaming or polling, and a service for storing analytics events. Optionally, you can configure LaunchDarkly to connect to alternate service endpoints.

Most customers do not need to configure service endpoints. You may need to configure service endpoints in the following situations:

* You are working with the LaunchDarkly federal instance. If you are using the [federal instance of LaunchDarkly](/home/infrastructure/federal), you must configure the SDK so that it connects to the federal instance for these services instead.
* You are working with the LaunchDarkly European Union (EU) instance. If you are using the EU instance of LaunchDarkly, you must configure the SDK so that it connects to the federal instance for these services instead. To learn which URLs to use instead, read the [EU instance documentation](/home/infrastructure/eu).
* You are using the Relay Proxy in proxy mode. To learn more, read [Using proxy mode](/sdk/features/relay-proxy-configuration/proxy-mode).
* You are using the [LaunchDarkly CLI](/home/getting-started/ldcli) to run a local `dev-server` for testing, and you want to access local flag values from there. To learn more, read [Using the LaunchDarkly CLI for local testing](/guides/flags/ldcli-dev-server).

The examples below show how to configure the SDK for each service. In most SDKs, you then need to pass the configuration in as a parameter when you initialize the client. To learn more, read [Configuration](/sdk/features/config).

Details about each SDK's configuration are available in the SDK-specific pages below.

## SDK-specific configuration

Use the SDK-specific pages for implementation details and code samples:

* [Client-side SDKs](/sdk/features/service-endpoint-configuration/client-side)
* [Server-side SDKs](/sdk/features/service-endpoint-configuration/server-side)