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PyLegifrance

Architecture

Layered architecture:

User → fonds/ (facades) → models/ (domain) → models/generated/ → client.py → Legifrance API
  1. Domain facades (fonds/) — high-level API per documentary fond (Code, JuriAPI, Loda, KaliAPI).
  2. Domain models (models/<fond>/) — business structures validated by Pydantic (search, consult, results).
  3. Generated models (models/generated/) — auto-generated from the Legifrance OpenAPI schema. See /en/concepts/generated-models.
  4. API client (client.py) — HTTPS/JSON communication, auth, timeouts.

Why this separation?

Section titled “Why this separation?”

The goal is to separate the user interface from the technical logic.

  • fonds/: domain facade

    • Stable, intuitive API for developers and legal professionals.
    • Hides the complexity of the Legifrance API.
    • Provides enriched business objects.
    • Protects client code from upstream API changes.

  • models/: data models

    • Precise structure of legal data.
    • Validation via Pydantic (strong typing, constraints).
    • Bidirectional conversion with API models.
    • Organized by technical concern.

See /en/concepts/fond-facade for the detailed reasoning.

Data flow

Section titled “Data flow”
flowchart TD
    dev[Developer]
    facade[Facade fonds/*]
    models[Models models/*]
    gen[Generated models]
    client[LegifranceClient]
    api[Legifrance API]


    dev -->|1. Calls| facade
    facade -->|2. Uses| models
    models -->|3. to_generated| gen
    gen -->|4. JSON payload| client
    client -->|5. HTTPS| api


    api -->|6. Response| client
    client -->|7. Forwards| gen
    gen -->|8. from_generated| models
    models -->|9. Processing| facade
    facade -->|10. Enriched objects| dev


    classDef external fill:#999,stroke:#333,stroke-width:2px
    classDef core fill:#9cf,stroke:#333,stroke-width:2px


    class dev,api external
    class facade,models,gen,client core

C4 diagrams

Section titled “C4 diagrams”

The C4 diagrams (context, containers, components) are described in PlantUML source in the legacy MkDocs docs and in raw/legifrance/ (awaiting pre-rendered SVG for native display in Starlight).

Key benefits

Section titled “Key benefits”
  • Stability: public interface independent of API changes.
  • Business models: features specific to the legal domain.
  • Robust validation: typing and Pydantic validation.
  • Intuitive structure: organized by documentary fond.

See also

Section titled “See also”