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

# Architecture

> Three independent services, talking only over HTTP

JaaS Skills is deliberately split into three codebases with no shared imports — only network calls — so each can be deployed, scaled, and released on its own schedule.

<CardGroup cols={3}>
  <Card title="jaas-ui" icon="window">
    Next.js 16 + TypeScript web app. Google/dev sign-in, search & browse, the drafts authoring workflow, tenant & sharing administration, guardrail policy management.
  </Card>

  <Card title="jaas-skills" icon="server">
    Python/FastAPI registry backend. Owns search, drafts, publish, tenants, sharing, and the guardrail policy store. Filesystem-backed in this local-first build.
  </Card>

  <Card title="jaas-guardrails" icon="shield-halved">
    Standalone content-safety scanning service. Owns the rule catalog *and* the engine that runs it. Reached only over REST — never imported.
  </Card>
</CardGroup>

<Note>
  **Why a separate guardrails service, not a library?** An earlier iteration vendored the rule catalog as a pinned git submodule, executed in-process. That still coupled the two codebases at the Python level. Moving the engine behind a versioned REST API means the guardrails service can add rule kinds or retune thresholds on its own release cadence — the registry never needs a code change to consume a newer catalog, only a network call.
</Note>

## Local stack

| Service             | Port             | Started by                                    |
| ------------------- | ---------------- | --------------------------------------------- |
| `jaas-skills` (API) | `127.0.0.1:8027` | `jaas-ui/run.sh` or `jaas-skills/run.sh`      |
| `jaas-ui` (web)     | `localhost:3027` | `jaas-ui/run.sh`                              |
| `jaas-guardrails`   | `127.0.0.1:8028` | either `run.sh`, if a sibling checkout exists |

Both `jaas-skills` and `jaas-guardrails` are optional relative to `jaas-ui` — the web app runs standalone against whatever `JAAS_API_URL` points at, including a backend it didn't start itself.