> For the complete documentation index, see [llms.txt](https://cluster-protocol.gitbook.io/whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cluster-protocol.gitbook.io/whitepaper/technical-architecture/system-architecture.md).

# System Architecture

The architecture follows a gateway pattern where all client requests: whether from the web frontend, the Python SDK, CodeXero, or external AI agents: hit a single Fastify-based API gateway. The gateway handles authentication, billing, rate limiting, and request routing.

<figure><img src="https://2560886960-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fo8bW2LCw3s9Oq1VIQ85p%2Fuploads%2FZgwSCz6E0CRXS1btRtKw%2Fimage.png?alt=media&amp;token=260f027d-277d-427a-9be4-bbde0a8659ef" alt=""><figcaption></figcaption></figure>