> For the complete documentation index, see [llms.txt](https://sestra.gitbook.io/sestra-whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sestra.gitbook.io/sestra-whitepaper/workflow-and-overview/high-level-system-flow.md).

# High Level System Flow

Sestra acts as an access decision layer. It sits between:

* API providers
* external verification systems

Sestra evaluates whether access should be granted and issues a temporary session when conditions are met.