Philosophy

The founding argument of Dura Lex.

The access to justice gap

5.1 billion people worldwide have unmet legal needs (World Justice Project, 2019). The economic cost is estimated at 0.5–3% of GDP (OECD, 2016). Access to law is not a niche problem — it is a structural deficit affecting the majority of the world's population.

In France, 31% of citizens have given up asserting their rights (Défenseur des droits, 2017–2020). Only 11% consult a lawyer as a first resort; 40% turn to the internet. Between legal aid (capped at €12,957/year) and lawyer fees (€300/hour average), a vast missing middle has access to neither.

The problem extends to organizations. A company operating across jurisdictions pays law firms in each country for often recurring questions — regulatory compliance, supplier disputes, local labor law. The cost is massive, quality is hard to verify, and legal knowledge does not capitalize from one case to the next. Worse: sensitive data — contracts, litigation strategy, due diligence — is sent to third-party providers with no real control over its processing.

The technological dead-ends

Existing solutions do not bridge this gap:

• Document search retrieves texts but does not reason. The user must already know what to look for.
• Judicial prediction promises success probabilities — but the Court of Appeal of Rennes concluded in 2017 that one such system provided "no added value". The French Ministry of Justice's DataJust project was abandoned after two years.
• Legal chatbots hallucinate. Even augmented by RAG (Retrieval-Augmented Generation), hallucination rates remain 17% (Lexis+ AI) to 43% (GPT-4) according to Magesh et al. (2025). Another study measures up to 88% of invented citations (Dahl et al., 2024).
• Legislative computation (Catala, OpenFisca) formalizes schedules and calculations, but does not qualify a legal situation. It answers "how much?", not "which law applies and with what arguments?".

There is a missing layer between raw legal data and reasoning: an open foundation, structured for the machine, useful to citizens and organizations alike.

The problem: black boxes

Citizens and lawyers increasingly use AI to handle legal questions — drafting contracts, researching case law, understanding their rights, preparing arguments. This trend will not reverse. AI is becoming a primary interface to the law.

The question is not whether people will use AI for law. They already do. The question is whether they will do it safely.

Current legal AI tools are black boxes. The data they rely on is opaque. Their reasoning is not auditable. Their confidentiality commitments are neither provable nor verifiable.

« Les engagements de confidentialité des fournisseurs de solutions d'IA sont ni prouvables ni vérifiables. »

— CNB, Guide de la déontologie et de l'intelligence artificielle, adopted March 13, 2026

The French National Bar Council (CNB) states that sharing client data with external AI systems may breach professional secrecy obligations (secret professionnel). No current commercial legal AI offers full auditability of its data sources, processing pipeline, or reasoning chain.

The risk is not theoretical. The Administrative Court of Grenoble rendered in December 2025 the first French decisions sanctioning AI-generated legal filings, described as "anything but legally framed". Eight decisions followed in weeks, including the first targeting a lawyer (TJ Périgueux, December 2025). The CNB adopted its deontological guide on generative AI in direct response.

Disciplinary sanctions, civil liability, and criminal exposure under articles 226-13 and 226-14 of the French Penal Code.

References: CNB, Guide de la déontologie et de l'intelligence artificielle, March 2026. CNB, Guide pratique d'utilisation des systèmes d'IAG, September 2024. CNB, Grille de lecture — Intelligence artificielle, June 2025. TA Grenoble, 3 December 2025, n°2510860. TJ Périgueux, 18 December 2025, n°23/00452.

The mission

Dura Lex does not aim to prevent AI usage in law — it aims to make it safe.

Four pillars:

Safety

Strict guidelines, quality checks, content quality levels on every document. The system never hides uncertainty — it expresses it. Every document carries its reliability level. Every gap in coverage is flagged. A quality_check tool lets the AI self-audit its own response against the corpus.

Transparency

Everything is traceable and auditable. Every document has a provenance. Every enrichment is tagged with its method and confidence level. Every reasoning path can be verified against the source. content_quality shows document reliability. needs_review flags anomalies. translation_quality distinguishes official from machine translations.

Sovereignty

The entire stack can run on-premise, on sovereign European infrastructure, or fully air-gapped. No dependency on foreign cloud providers. No data leaves without explicit choice. The law comes to your data — not your data to someone else's cloud.

Professional secrecy

Conversations, queries, and research stay under the user's control. Multiple privacy modes from standard to air-gapped. Designed for the requirements of secret professionnel as defined by the CNB.

The answer: digital commons

Dura Lex is the opposite of a black box.

Open source, open data

Component	License	Rationale
Software (all packages)	MIT	Maximum adoption — anyone can use, fork, embed, commercialize without restriction
Enriched data (corpus, edges, annotations)	ODbL	Share-alike for data — improvements flow back to the commons
Raw source data	Per-source (Licence Ouverte 2.0, CC0)	Government open data — already public

This is the OpenStreetMap model: permissive code, copyleft data. The ecosystem grows because everyone can build on it. The data stays open because no one can close it.

Credibility by audit, not by reputation

Traditional legal publishing relies on curation: editorial committees select, rank, interpret. This work has immense value — but it implies a filter. A minority interpretation, however legally founded, may not be retained. An emerging jurisprudential trend may fly under the radar.

Dura Lex discards nothing. 3.4 million decisions are there, with their contradictions, their tensions, their minority positions. The system does not make editorial judgments about what deserves to be seen — it structures everything, and lets formal reasoning surface what is relevant for a given situation.

Authority does not come from a name on the cover — it comes from traceability: every assertion points to its source, every reasoning is reproducible, every conclusion is auditable. The data is the proof.

Auditability

Every link in the chain is visible and verifiable:

• Every document carries its content quality level — from raw OCR to jurist-reviewed
• Every edge (cross-reference, amendment, citation) carries its provenance
• Every translation is tagged with its method — official, machine, human-reviewed
• Safety guidelines are loaded before every research session
• The AI can run a quality check against the corpus after answering

This traceability makes the system natively compliant with the EU AI Act (mandatory traceability, Article 53) and Article 33 of the French law of March 23, 2019 (sourced arguments, not judicial predictions).

Doubt is always expressed

The system never pretends to certainty it does not have. Missing data, low-quality OCR, incomplete temporal coverage, untested jurisdictions — all are surfaced, never hidden.

When a tool tells you "here is the answer" without showing you where it looked, what it found, and what it might have missed — that is a black box.

When every step is inspectable, every limitation is stated, and every source is cited — that is a digital common.

Unique positioning

We have identified and analyzed over 80 legal MCP servers across 40+ jurisdictions. The majority are API relays: they forward queries to Légifrance, CourtListener, or EUR-Lex with minimal tool descriptions and no behavioral framing.

Dura Lex is the only project with a mandatory safety_guidelines tool — a call the model must make before any research, injecting rules of conduct and jurisdictional specifics. No other project has an equivalent. We are also the only project with a quality feedback mechanism allowing the model to report issues in the data.

Legal boundary

Dura Lex provides documentary legal information, which is explicitly permitted by Article 66-1 of the French law of December 31, 1971. It does not provide personalized legal advice. This boundary is built into the architecture itself: the server provides sources and safety rules, not conclusions.