> For the complete documentation index, see [llms.txt](https://oten.gitbook.io/identity-support/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://oten.gitbook.io/identity-support/integration/understand-sso-flow/flow-diagram.md).

# Flow Diagram

This page provides detailed visual diagrams of the SSO authentication flow, helping you understand exactly what happens during the login process.

## Understanding the Diagrams

These diagrams show:

* The complete OAuth 2.0 authorization code flow
* Interactions between user, application, and Oten IDP
* Different scenarios and error handling
* Security mechanisms in action

## Complete OAuth 2.0 Flow

### Main Authentication Flow

## Security Mechanisms

<figure><img src="/files/G32UjJLardaLz54qfGYF" alt=""><figcaption></figcaption></figure>

### PKCE Flow (for Public Clients)

<figure><img src="/files/eJkkEbScycG3m3v10atM" alt=""><figcaption></figcaption></figure>

> 📖 **Comprehensive PKCE Guide**: For detailed implementation examples for SPAs and native apps, see the [PKCE Implementation Guide](broken://pages/5y0aMLenY28PhaF6VqYC).

**Next**: Learn about the [Step-by-Step Process](https://gitlab.silvertiger.tech/documents/idp/-/blob/main/sso-flow/step-by-step.md) for detailed explanations of each step