SAOS MCP - Polish Court Judgments

An MCP server that connects Claude (and other AI clients) to SAOS - the official public database of Polish court judgments (System Orzecznictwa Sądów Powszechnych i Sądu Najwyższego).

Who is this for? Polish lawyers, legal researchers, and law students who want to search and analyze Polish court decisions directly inside Claude, Cursor, or any MCP-compatible AI client. No API key required - SAOS is a public database.

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Features

• Full-text search across hundreds of thousands of Polish judgments from courts of appeal, regional courts, and district courts
• Filter by case number, judge name, court type, judgment type, and date range
• Retrieve full judgments - metadata, operative part (sentencja), and complete reasoning (uzasadnienie)
• Local file archive - in stdio mode, saves each retrieved judgment as a .md file for offline reference
• In-memory cache (15 min TTL) to avoid redundant API calls
• Timeout protection - 15-second abort signal on all API requests
• Dual transport - stdio for local Claude Desktop use, HTTP for remote/hosted deployment

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Dla polskich prawników

SAOS MCP pozwala Claude'owi przeszukiwać bazę orzeczeń sądowych i analizować je bezpośrednio w rozmowie. Nie musisz otwierać przeglądarki ani kopiować tekstów — wystarczy zapytać Claude'a.

Jak zacząć

Krok 1. Zainstaluj Node.js (wersja 20 lub nowsza). To jedyna techniczna rzecz do zrobienia.

Krok 2. Otwórz plik konfiguracyjny Claude Desktop:

• Windows: naciśnij Win + R, wpisz %APPDATA%\Claude i otwórz plik claude_desktop_config.json
• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Krok 3. Dodaj poniższy wpis do sekcji mcpServers (jeśli plik jest pusty, wklej całość):

{
  "mcpServers": {
    "SAOS": {
      "command": "npx",
      "args": ["-y", "@thescalablelegalmarketer/saos-mcp"]
    }
  }
}

Krok 4. Zapisz plik i zrestartuj Claude Desktop. Przy pierwszym uruchomieniu Claude automatycznie pobierze serwer.

Przykładowe zapytania

Znajdź w SAOS 3 orzeczenia z lat 2020-2025 dotyczące sporów
o nienależyte wykonanie umowy wdrożeniowej oprogramowania.
Dla każdego podaj:
- sentencję (dosłowny cytat)
- podstawę prawną
- główny argument sądu

Wyszukaj orzeczenia dotyczące praw autorskich do oprogramowania
stworzonego przez pracownika na rzecz pracodawcy. Jakie stanowisko
zajmowały sądy w kwestii własności kodu?

Uwaga: Orzeczenia w bazie SAOS mają zanonimizowane dane stron (zamiast nazwisk widnieje (...)). To cecha samej bazy danych, nie ograniczenie narzędzia.

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Installation

Claude Desktop (recommended)

Prerequisites: Node.js 20+ must be installed on your machine.

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "SAOS": {
      "command": "npx",
      "args": ["-y", "@thescalablelegalmarketer/saos-mcp"]
    }
  }
}

Restart Claude Desktop. The server starts automatically - no separate process needed.

Config file location:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

Remote HTTP (self-hosted)

{
  "mcpServers": {
    "SAOS": {
      "url": "https://your-domain.com/mcp"
    }
  }
}

See Deployment for instructions on hosting your own instance.

From source (development)

git clone https://github.com/pawelojdowski/saos-mcp
cd saos-mcp
npm install
npm run build

{
  "mcpServers": {
    "SAOS": {
      "command": "node",
      "args": ["C:\\PATH\\TO\\saos-mcp\\dist\\index.js"]
    }
  }
}

Environment variable (stdio mode only):

• SAOS_OUTPUT_DIR - directory for saved .md judgment files (default: ~/Documents/saos-orzeczenia)

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Tools

saos_search_judgments

Search for judgments in the SAOS database. Results sorted by date (newest first). All parameters optional.

Parameter	Type	Description
query	string	Full-text search across all fields (content + metadata)
caseNumber	string	Exact case number, e.g. VIII GC 23/24
judgeName	string	Judge's full name
keyword	string	SAOS thematic keyword, e.g. odszkodowanie (damages)
ccCourtType	string	APPEAL / REGIONAL / DISTRICT
judgmentType	string	SENTENCE / DECISION / RESOLUTION
dateFrom	string	Format YYYY-MM-DD
dateTo	string	Format YYYY-MM-DD
pageSize	number	Max 20, default 10
pageNumber	number	Starting from 0

Tip: SAOS full-text search requires all keywords to appear in the text. Use multiple specific terms rather than quoted phrases, e.g. umowa wdrożeniowa oprogramowanie nienależyte wykonanie.

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saos_get_judgment

Retrieve a full judgment by ID. Returns metadata, verbatim operative part (sentencja), and full reasoning (uzasadnienie). In stdio mode, also saves a .md file to SAOS_OUTPUT_DIR.

Parameter	Type	Description
id	number	Required. Judgment ID from saos_search_judgments results

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saos_list_courts

Returns a list of common courts (ID, name, type). Use this to find court IDs for filtering.

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Example prompt

Use SAOS to find 3 judgments from 2024–2025 concerning disputes over
defective implementation of ERP software contracts.
For each judgment call saos_get_judgment and provide:

1. Operative part - quote verbatim from the [VERBATIM QUOTE] section
2. Ratio decidendi - summarize the main reason for the ruling from the
   "Sąd zważył" section of the reasoning
3. Legal basis - which provisions did the court invoke

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Development

npm run dev          # stdio server (TypeScript, no build needed)
npm run dev:http     # HTTP server on port 3000
npm run build        # type-check + esbuild bundle → dist/
npm run start        # run compiled stdio bundle
npm run start:http   # run compiled HTTP server

Deployment

Build and run with Docker:

docker build -t saos-mcp .
docker run -p 3000:3000 saos-mcp

MCP endpoint: http://localhost:3000/mcp Health check: http://localhost:3000/health

Deploy to Railway, Render, or Fly.io using the included Dockerfile.

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Project structure

saos-mcp/
├── src/
│   ├── types.ts        ← SAOS API TypeScript interfaces
│   ├── api.ts          ← SAOS API client + in-memory cache
│   ├── format.ts       ← HTML parsing, text formatting, file saving
│   ├── server.ts       ← createMcpServer() factory - tool registration
│   ├── index.ts        ← stdio entry point
│   └── http-server.ts  ← HTTP entry point + /health endpoint
├── dist/               ← build output (gitignored)
│   ├── index.js        ← stdio bundle (with #!/usr/bin/env node shebang)
│   └── http-server.js  ← HTTP bundle
├── build.mjs           ← esbuild config (two outputs in parallel)
├── tsconfig.json       ← type-check only (noEmit), bundling via esbuild
├── server.json         ← MCP marketplace manifest
├── Dockerfile          ← multi-stage build → image with http-server.js
├── icon.svg
└── package.json

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Known limitations

• Partial coverage - SAOS indexes mainly courts of appeal and regional courts; district courts are less complete
• Anonymized parties - the API returns (...) instead of party names; this is a feature of the SAOS database
• decision field - available mainly for Supreme Court judgments; for common courts the operative part is extracted via HTML parsing
• In-memory cache - 15 min TTL, resets on process restart
• HTTP mode - does not save .md files (no access to the user's file system)

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About SAOS

SAOS (System Analizy Orzeczeń Sądowych - System of Analysis of Court Judgments) is an open academic project led by the Interdisciplinary Centre for Mathematical and Computational Modelling (ICM) at the University of Warsaw, funded by the National Centre for Research and Development (grant IS-1/040/NCBR/2014).

The platform aggregates judgments from Polish common courts, administrative courts, the Supreme Court (Sąd Najwyższy), the Constitutional Tribunal (Trybunał Konstytucyjny), and the National Appeals Chamber (KIO). Data is imported automatically from official court portals. Personal data appearing in judgments is processed under GDPR Art. 6(1)(e) (public interest); responsibility for its publication rests with the source court systems.

The API is freely accessible with no authentication required.

Disclaimer: This tool is intended for legal research only and is not a substitute for professional legal advice. Always verify citations against primary sources before relying on them in legal proceedings.

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License

Apache-2.0 © Paweł Ojdowski