> ## 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.

# 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.

<CardGroup cols={2}>
  <Card title="Custom service config" icon="folder-open" href="/services/xbox-services/fundamentals/s2s-auth-calls/custom-service-config/index">
    Documentation for custom service config.
  </Card>

  <Card title="S2s calls" icon="folder-open" href="/services/xbox-services/fundamentals/s2s-auth-calls/s2s-calls/index">
    Documentation for s2s calls.
  </Card>

  <Card title="Service authentication" icon="id-card" href="/services/xbox-services/fundamentals/s2s-auth-calls/service-authentication/index">
    Documentation for service authentication.
  </Card>

  <Card title="Authentication and s2s" icon="right-to-bracket" href="/services/xbox-services/fundamentals/s2s-auth-calls/live-s2s-auth-calls-nav">
    This section describes how to authenticate with XBOX services, and make service-to-service calls to XBOX services from the title.
  </Card>
</CardGroup>

## See also

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


## Related topics

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