MCP Nsa

mcp-nsa

Installation (one command)

Published on npm + the MCP Registry (io.github.matematicsolutions/mcp-nsa). Run without cloning:

npx -y @matematicsolutions/mcp-nsa

MCP client configuration (stdio):

{ "mcpServers": { "mcp-nsa": { "command": "npx", "args": ["-y", "@matematicsolutions/mcp-nsa"] } } }

(Building from source - below.)

MCP server for the case law of the Polish administrative courts - Naczelny Sad Administracyjny / NSA (Supreme Administrative Court) + 16 Wojewodzkie Sady Administracyjne / WSA (regional administrative courts) - via CBOSA (Centralna Baza Orzeczen Sadow Administracyjnych - the administrative courts' central case-law database) (orzeczenia.nsa.gov.pl).

Why

SAOS (the common-courts case-law analysis system) does not index the administrative courts. Yet that is exactly where the substantive case law lives:

• GDPR / data protection - decisions of the President of UODO appealed to the WSA, cassation appeals to the NSA
• Taxes - individual tax rulings, decisions of tax authorities
• Customs and excise
• Administrative permits, concessions
• Review of public-administration activity

mcp-nsa closes this gap. Coverage: 2,390,000+ rulings (verified live 2026-07-08 across the full date range), from 1981 to today.

Tools

• `search(query, caseNumber?, court?, dateFrom?, dateTo?, pageNumber?)`
• search by keyword, case number, court, date. Fetches the top 5 full rulings (case number, court, date, panel, keywords, legal basis, excerpt).
• `get_judgment(doc_id)` - full ruling by 10-character hex doc_id (from the CBOSA URL, e.g. 7E50984BB7).
• `search_by_case(caseNumber)` - shortcut: search by case number (e.g. III OSK 1377/23, I SA/Gl 659/22).

Every response contains structuredContent.citations with the fields: title, url (CBOSA), case_number, court, judgment_date, decision_type, snippet, doc_id. Patron reads this field automatically and surfaces it in the UI panel as the section "Rulings from CBOSA (NSA / WSA - administrative courts)".

Stack

• Node 18+
• @modelcontextprotocol/sdk
• Stdio transport
• https + regex HTML parser (zero external deps beyond the SDK)
• 500 ms throttle between requests (2 req/s)
• SSL: rejectUnauthorized: false - the CBOSA chain is sometimes incomplete on some machines; public rulings, no PII, MITM risk negligible against the benefit. See: LDH issue #167.

Build + run

npm install

npm run build node dist/index.js # starts the server on stdio

Wiring into Patron

In patron/backend/mcp-servers.json (alongside mcp-saos and mcp-eu-sparql):

{

"name": "nsa", "transport": "stdio", "command": "node", "args": ["C:/Users/ /mcp-nsa/dist/index.js"], "enabled": true }

Smoke test

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"s","version":"0"}}}

{"jsonrpc":"2.0","method":"notifications/initialized"} {"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"search","arguments":{"query":"RODO art 6"}}}' \ | node dist/index.js

Should return ~1500 hits + the top 5 with Polish NSA/WSA case numbers + CBOSA URLs

• structuredContent.citations.

Lineage

Implementation rewritten in TypeScript on the basis of the HTTP/HTML contract from legal-data-hunter/sources/PL/NSA (Python + BeautifulSoup, MIT). It does not import the source code - it reproduces the query pattern and HTML parsing.

License

MIT.

Part of MateMatic

This connector queries its source live. It is one of the Polish and EU source connectors bundled in PATRON and works with any MCP client.

• Poland, one server for all sources: prawo-pl-mcp · each source on its own: mcp-saos · mcp-nsa (this repo) · mcp-isap · mcp-krs · mcp-eureka · kio-orzeczenia-mcp
• European Union: mcp-eu-sparql (live) · mcp-eu-compliance (offline corpus)
• A prepared corpus of Polish and EU law with a citation graph: Repertorium

mcp-saos, mcp-nsa, mcp-isap, mcp-krs and mcp-eu-sparql share one structuredContent.citations contract: each tool returns an array of {title, url, snippet?, ...metadata} that legal agents can render directly in their citation panel.

See matematicsolutions/.github for the full org profile.