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

# S2s auth calls

> Guides for XBOX Live authentication, XSTS tokens, and service-to-service calls from title back ends, including Partner Center config and S2S patterns.

Explore s2s auth calls topics for XBOX game development.

> [card] [Custom service config](https://docs.xbox.com/services/xbox-services/fundamentals/s2s-auth-calls/custom-service-config/index.md)
>
> Documentation for custom service config.

> [card] [S2s calls](https://docs.xbox.com/services/xbox-services/fundamentals/s2s-auth-calls/s2s-calls/index.md)
>
> Documentation for s2s calls.

> [card] [Service authentication](https://docs.xbox.com/services/xbox-services/fundamentals/s2s-auth-calls/service-authentication/index.md)
>
> Documentation for service authentication.

> [card] [Authentication and s2s](https://docs.xbox.com/services/xbox-services/fundamentals/s2s-auth-calls/live-s2s-auth-calls-nav.md)
>
> This section describes how to authenticate with XBOX services, and make service-to-service calls to XBOX services from the title.

## See also

* [Game binding](https://docs.xbox.com/services/xbox-services/fundamentals/game-binding/index.md)
* [Identity](https://docs.xbox.com/services/xbox-services/fundamentals/identity/index.md)
* [Portal config](https://docs.xbox.com/services/xbox-services/fundamentals/portal-config/index.md)
* [Rta](https://docs.xbox.com/services/xbox-services/fundamentals/rta/index.md)
* [Sandboxes](https://docs.xbox.com/services/xbox-services/fundamentals/sandboxes/index.md)
* [XBOX services API](https://docs.xbox.com/services/xbox-services/fundamentals/xbox-services-api/index.md)


## Related topics

- [Fundamentals](https://docs.xbox.com/services/xbox-services/fundamentals/index.md)
- [XBOX services API](https://docs.xbox.com/services/xbox-services/fundamentals/xbox-services-api/index.md)
- [Game binding](https://docs.xbox.com/services/xbox-services/fundamentals/game-binding/index.md)
- [Portal config](https://docs.xbox.com/services/xbox-services/fundamentals/portal-config/index.md)
- [Sandboxes](https://docs.xbox.com/services/xbox-services/fundamentals/sandboxes/index.md)