Lithuanian Law MCP Server

Lithuanian Law MCP Server

The Lithuanian law corpus is now served through the Ansvar Gateway. Connect your AI assistant (Claude, Copilot, Cursor, custom MCP client) to https://gateway.ansvar.eu/mcp — one OAuth connection, free tier available, covering this corpus plus EU regulations, national law across 28 audited jurisdictions, and CVE/security intelligence, every result with a verbatim source citation. Start at https://ansvar.eu/docs/quickstart

Connect

Claude Code (one line):

claude mcp add ansvar --transport http https://gateway.ansvar.eu/mcp

Claude Desktop / Cursor — add to claude_desktop_config.json (or mcp.json):

{
  "mcpServers": {
    "ansvar": {
      "type": "url",
      "url": "https://gateway.ansvar.eu/mcp"
    }
  }
}

Claude.ai — Settings → Connectors → Add custom connector → paste https://gateway.ansvar.eu/mcp

First request opens an OAuth signup flow (setup details: ansvar.eu/docs/quickstart). After signup, your client is bound to your account; tier (free / premium / team / company) determines fan-out, quota, and which downstream MCPs are reachable.

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Self-host this MCP

You can also clone this repo and build the corpus yourself. The schema, fetcher, and tool implementations all live here. What is not in the repo is the pre-built database — TDM and standards-licensing constraints on the upstream sources mean we host the corpus on Ansvar infrastructure rather than redistribute it as a public artifact.

Build your own: run this repo's ingestion script (entry-point varies per repo — typically scripts/ingest.sh, npm run ingest, or make ingest; check the repo root).

The e-Seimas alternative for the AI age.

Query 12,045 Lithuanian statutes -- from the Asmens duomenų teisinės apsaugos įstatymas and Baudžiamasis kodeksas to the Civilinis kodeksas, Darbo kodeksas, and more -- directly from Claude, Cursor, or any MCP-compatible client.

If you're building legal tech, compliance tools, or doing Lithuanian legal research, this is your verified reference database.

Built by Ansvar Systems -- Stockholm, Sweden

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Why This Exists

Lithuanian legal research is scattered across e-Seimas, TAR (Teisės aktų registras), and EUR-Lex. Whether you're:

• A lawyer validating citations in a brief or contract
• A compliance officer checking if a statute is still in force
• A legal tech developer building tools on Lithuanian law
• A researcher tracing legislative provisions across 12,045 statutes

...you shouldn't need dozens of browser tabs and manual cross-referencing. Ask Claude. Get the exact provision. With context.

This MCP server makes Lithuanian law searchable, cross-referenceable, and AI-readable.

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Example Queries

Once connected, just ask naturally:

• "Ieškoti 'asmens duomenų apsauga' -- kokias pareigas nustato ADTAĮ?"
• "Ar Baudžiamojo kodekso 196 straipsnis vis dar galioja?"
• "Rask nuostatas apie darbuotojų apsaugą Darbo kodekse"
• "Kokie ES teisės aktai įgyvendinti per Civilinį kodeksą?"
• "Kurie Lietuvos įstatymai įgyvendina BDAR?"
• "Patikrink nuorodą: DK 38 str. 1 d."
• "Pateik teisinę poziciją dėl duomenų apsaugos pažeidimų pagal ADTAĮ"
• "Ar Lietuvos kibernetinio saugumo įstatymas atitinka NIS2?"

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What's Included

Verified data only -- every citation is validated against official sources (TAR, e-Seimas). Zero LLM-generated content.

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See It In Action

Why This Works

Verbatim Source Text (No LLM Processing):

• All statute text is ingested from TAR (Teisės aktų registras) official sources
• Provisions are returned unchanged from SQLite FTS5 database rows
• Zero LLM summarization or paraphrasing -- the database contains regulation text, not AI interpretations

Smart Context Management:

• Search returns ranked provisions with BM25 scoring (safe for context)
• Provision retrieval gives exact text by statute number + article/section
• Cross-references help navigate without loading everything at once

Technical Architecture:

TAR API → Parse → SQLite → FTS5 snippet() → MCP response
            ↑                     ↑
     Provision parser      Verbatim database query

Traditional Research vs. This MCP

Traditional: Search TAR → Download PDF → Ctrl+F → Cross-reference with other statutes → Check EUR-Lex for EU basis → Repeat

This MCP: "Kokie ES teisės aktai yra ADTAĮ 3 str. pagrindas?" → Done.

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Available Tools (13)

Core Legal Research Tools (8)

EU Law Integration Tools (5)

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EU Law Integration

Lithuania is an EU member state. Lithuanian legislation directly transposes EU directives and implements EU regulations, creating a tight mapping between Lithuanian and EU law.

Key areas of EU-Lithuanian law alignment:

• GDPR (2016/679) -- implemented via the Asmens duomenų teisinės apsaugos įstatymas (ADTAĮ, Law No. XI-1374)
• NIS2 Directive (2022/2555) -- implemented via the Kibernetinio saugumo įstatymas
• eIDAS Regulation (910/2014) -- applicable directly; supplemented by national e-signature rules
• DORA (2022/2554) -- financial sector digital resilience obligations
• AI Act (2024/1689) -- EU regulation applicable directly across all member states

The EU bridge tools provide bi-directional lookup: find which Lithuanian statutes implement a given EU act, or find which EU acts underpin a given Lithuanian provision.

See EU_INTEGRATION_GUIDE.md for detailed documentation.

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Data Sources & Freshness

All content is sourced from authoritative Lithuanian legal databases:

• TAR -- Teisės aktų registras (Register of Legal Acts), the official Lithuanian legal database
• e-Seimas -- Lietuvos Respublikos Seimas (Lithuanian Parliament) legislative database
• EUR-Lex -- Official EU law database (metadata only)

Automated Freshness Checks (Daily)

A daily GitHub Actions workflow monitors all data sources:

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Security

This project uses multiple layers of automated security scanning:

See SECURITY.md for the full policy and vulnerability reporting.

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Important Disclaimers

Legal Advice

THIS TOOL IS NOT LEGAL ADVICE

Statute text is sourced from official TAR/e-Seimas publications. However:

• This is a research tool, not a substitute for professional legal counsel
• Verify critical citations against primary sources for court filings
• EU cross-references are extracted from Lithuanian statute text, not EUR-Lex full text
• Always confirm current in-force status via TAR before relying on a provision professionally

Before using professionally, read: DISCLAIMER.md | PRIVACY.md

Client Confidentiality

Queries go through the Claude API. For privileged or confidential matters, use on-premise deployment. See PRIVACY.md for Lietuvos advokatūra (Lithuanian Bar Association) compliance guidance.

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Documentation

• EU Integration Guide -- Detailed EU cross-reference documentation
• EU Usage Examples -- Practical EU lookup examples
• Security Policy -- Vulnerability reporting and scanning details
• Disclaimer -- Legal disclaimers and professional use notices
• Privacy -- Client confidentiality and data handling

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Development

Setup

git clone https://github.com/Ansvar-Systems/Lithuanian-law-mcp
cd Lithuanian-law-mcp
npm install
npm run build
npm test

Running Locally

npm run dev                                       # Start MCP server
npx @anthropic/mcp-inspector node dist/index.js   # Test with MCP Inspector

Data Management

npm run ingest              # Ingest statutes from TAR
npm run build:db            # Rebuild SQLite database
npm run check-updates       # Check for amendments and new statutes

Performance

• Search Speed: <100ms for most FTS5 queries
• Database Size: 262 MB (comprehensive corpus)
• Reliability: 100% ingestion success rate

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More Ansvar MCPs

Full fleet coverage at ansvar.eu/coverage.

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

Priority areas:

• EU Regulations MCP integration (full EU law text, CJEU case law)
• Historical statute versions and amendment tracking
• Constitutional Court (Konstitucinis Teismas) case law expansion
• Administrative court decisions

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Roadmap

• Core statute database with FTS5 search

• Full corpus ingestion (12,045 statutes, 89,705 provisions)

• EU law integration tools

• Vercel Streamable HTTP deployment

• Daily freshness checks

• Case law expansion (Supreme Court, Constitutional Court)

• Historical statute versions (amendment tracking)

• English translations for key statutes

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Citation

If you use this MCP server in academic research:

@software{lithuanian_law_mcp_2026,
  author = {Ansvar Systems AB},
  title = {Lithuanian Law MCP Server: Production-Grade Legal Research Tool},
  year = {2026},
  url = {https://github.com/Ansvar-Systems/Lithuanian-law-mcp},
  note = {Comprehensive Lithuanian legal database with 12,045 statutes and 89,705 provisions}
}

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License

Apache License 2.0. See LICENSE for details.

Data Licenses

• Statutes & Legislation: LT-Statutory-PD — Lithuanian statutory public domain under Autorių teisių ir gretutinių teisių įstatymas 5 str. (ATGTĮ), which excludes legal acts, official documents of administrative, legal or regulatory nature (decisions, rulings, regulations, norms, territorial-planning documents), their official translations, officially registered drafts of legal acts, and folklore works from copyright protection. Verbatim basis: WIPO Lex Lithuanian PDF (consolidated through XIV-970/2022). Commercial reuse permitted, no attribution required. The ATGTĮ point 4 covering officially registered drafts of legal acts is the widest preparatory-doc clause in the EU set. Verified 2026-05-17.
• EU Metadata: EUR-Lex (EU public domain)

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About Ansvar Systems

We build AI-accelerated compliance and legal research tools for the European market. This MCP server started as our internal reference tool for Lithuanian law -- turns out everyone building for the Baltic market has the same research frustrations.

So we're open-sourcing it. Navigating 12,045 statutes shouldn't require a law degree.

ansvar.eu -- Stockholm, Sweden

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