Retrieval Augmented Graph Tax Answer Generator.

flowchart LR
    %% ---------- Ingest ----------
    subgraph Ingest [Ingest - build the graph]
        direction TB
        F[Finlex laki / asetus<br/>+ Säädöskokoelma] --> P{Parsers}
        V[Vero · ohje · kannanotto · päätös] --> P
        K[KHO / KVL rulings] --> P
        T[Tax treaties] --> P
        P --> N[Typed nodes<br/>LAW · SECTION · CHAPTER<br/>CASE · GUIDE · TREATY]
        P --> E[Typed edges<br/>parent_of · cites · amends<br/>interprets · applies · defines]
        N --> GS[(Graph store<br/>SQLite)]
        E --> GS
        N --> C[Chunker]
        C --> EM[voyage-3-large<br/>1024-dim]
        EM --> VS[(Vector store<br/>LanceDB)]
    end

    %% ---------- Retrieve ----------
    subgraph Retrieve [Retrieve - answer one question]
        direction TB
        Q[Question] --> QR[Query rewrite<br/>FI / EN synonyms]
        QR --> H[Hybrid search<br/>dense + BM25 RRF]
        VSr[(Vector store)] --> H
        H --> RR[Rerank<br/>cosine + authority<br/>+ recency + term]
        GSr[(Graph store)] --> RR
        RR --> AS[Assemble context<br/>render typed cross-refs<br/>between cited sections]
        AS --> GEN[LLM · grounded answer<br/>with cited section ids]
        GEN --> CF[Confidence grader<br/>high · medium · low]
        AS --> ORB[Provenance orbit<br/>sub-graph for the UI]
        GEN --> OUT([Answer<br/>+ citations + cost])
        CF --> OUT
        ORB --> OUT
    end

    %% Cross-links so the two halves read as one system.
    GS -.-> GSr
    VS -.-> VSr

    classDef store fill:#fff7eb,stroke:#944921,stroke-width:1.2px;
    classDef io fill:#fafafa,stroke:#1a1c1b,stroke-width:1.2px;
    class GS,VS,GSr,VSr store;
    class OUT io;