lt-eli-mcp

An MCP server for the Lithuanian Register of Legal Acts (TAR) via the data.gov.lt open-data API. It searches Lithuanian legislation by title and fetches full text, with verifiable citations.

Part of the MateMatic eu-legal-mcp production line - after PL, DE, AT, ES, FI, IE, NL, SE, FR, LU, DK, CZ and HR. Same citation contract, TAR source. This connector reads a REST-JSON open-data API (the data.gov.lt Spinta endpoint).

Scope. This MVP searches acts by title substring, returns metadata, and fetches the full Lithuanian text. ~CC BY 4.0 open data; acts are addressed by their TAR code (tar_kodas). Language: Lithuanian. Every response carries a dataset_note.

ELI is national, not data.europa.eu. Lithuania has no data.europa.eu ELI for the TAR dataset. eli_uri carries the canonical e-tar.lt legalAct URL (the stable national identifier), which is also the source_url. Every response carries an eli_note saying so.

The tools

Every response carries the contract: eli_uri (the e-tar.lt URL, e.g. https://e-tar.lt/portal/lt/legalAct/...), human_readable_citation (title + official number), and source_url.

Related MCP server: Estonian Law MCP Server

Install

Run it with no install step (once published to PyPI):

uvx lt-eli-mcp

Or from source:

cd lt-eli-mcp
pip install -e .

Configure (Claude Code / any MCP client)

{
  "mcpServers": {
    "lt-eli-mcp": { "command": "lt-eli-mcp" }
  }
}

Environment:

• LT_ELI_BASE_URL - default https://get.data.gov.lt

• LT_ELI_CACHE_DIR - default ~/.matematic/cache/lt-eli

• LT_ELI_AUDIT_DIR - default ~/.matematic/audit

No API key. The data.gov.lt open-data API is keyless.

Governance

• Public data only - read-only against data.gov.lt; no client data leaves the machine.

• Audit log - every tool call appends one JSON line to ~/.matematic/audit/lt-eli-mcp.jsonl.

• Vendor-neutral - talks only to get.data.gov.lt; no LLM provider, no telemetry.

• Verifiable citations - every response is independently checkable via source_url.

See CONSTITUTION.md and DISCOVERY.md.

Tests

pip install -e ".[dev]"
pytest tests/test_instructions_drift.py tests/test_parse.py -v   # offline
pytest tests/test_smoke.py -v                                    # hits live data.gov.lt

Licence

Apache-2.0. © Matematic Solutions / Wieslaw Mazur. TAR data is CC BY 4.0; relayed with attribution and a source_url.