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" }
  }
}

Windows 11 with Smart App Control

Smart App Control blocks unsigned executables, which covers uvx.exe, pip.exe and the lt-eli-mcp.exe launcher that pip writes at install time. The python.exe and py.exe from the python.org installer are signed by the Python Software Foundation, so running the module through the interpreter works:

python -m pip install lt-eli-mcp
python -m lt_eli_mcp

pip.exe is blocked for the same reason, so install with python -m pip, not pip install. If python is not on PATH, use the Windows launcher: py -3 -m lt_eli_mcp.

{ "mcpServers": { "lt-eli-mcp": { "command": "python", "args": ["-m", "lt_eli_mcp"] } } }

Do not turn Smart App Control off to work around this - it cannot be re-enabled without reinstalling Windows.

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.