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

# User sign-in

> Overview of XBOX services user sign-in, account access, and identity APIs including XAL and XUser for GDK and cross-platform title development.

This section covers authentication and account access, XAL, and `XUser` API topics.

## In this section

[Account authentication and access overview](/services/xbox-services/fundamentals/identity/auth/live-authentication-overview)
Describes how to authenticate and access accounts, use the XBOX Authentication Library, and use XUser API contents.

[Troubleshooting XBOX services sign-in](/services/xbox-services/fundamentals/identity/auth/live-troubleshooting-sign-in)
Troubleshooting issues with XBOX services sign-in, such as correct sandbox and configuration IDs.


## Related topics

- [XGameSave API overview](/build/core-features/common/game-save/xgamesave.md)
- [Game Saves walkthroughs and samples](/build/core-features/common/game-save/game-saves-walkthroughs-and-samples.md)
- [User identity](/services/xbox-services/fundamentals/identity/xs-identity-overview.md)
- [XR-052 User state, title-save location, and roaming](/publishing/certification/xr/xr-052.md)
- [User authentication and ownership](/build/steam-porting-guide/features/user-authentication-and-ownership.md)