## High-level architecture

```mermaid
flowchart TD
    Cellar[Cellar API]
    Frontend[React Frontend]

    subgraph "FastAPI backend"
        client[Cellar Client]
        conv[Formex -> HTML renderer]
        FastAPI[REST API]
    end

    Cellar --> meta@{ shape: docs, label: "XML/RDF Metadata"}
    Cellar --> docs@{ shape: docs, label: "Formex 4 content"}

    meta --> client
    docs --> client

    client -- Formex --> FastAPI
    client -- Formex --> conv

    conv -- HTML --> FastAPI

    FastAPI -- TOC, HTML article text --> Frontend
```

## Resources

- Formex 4
  - [XML schema](https://op.europa.eu/documents/3938058/5910419/formex_manual_on_screen_version.html/)
  - [Physical specifications](https://op.europa.eu/documents/3938058/5896514/physical-specifications/)
- [Cellar](https://op.europa.eu/en/web/cellar/home)
  - [Publications API](https://op.europa.eu/en/web/cellar/cellar-data/publications)
  - [Metadata REST API](https://op.europa.eu/en/web/cellar/cellar-data/metadata/metadata-notices)
  - [Metadata SPARQL API](https://op.europa.eu/en/web/cellar/cellar-data/metadata/knowledge-graph)