Law Scrapper MCP

A comprehensive Model Context Protocol (MCP) server for accessing and analyzing Polish legal acts from the Sejm API, enabling AI-powered legal research and document analysis.

Features

• Comprehensive legal act access - Full access to Polish legal acts from Dziennik Ustaw (DU) and Monitor Polski (MP)

• Advanced search and filtering - Multi-criteria search by date, type, keywords, publisher, and status

• Result Store with chained filtering - Store search results and filter with regex, type/status/year match, date ranges, sorting

• Document Store pattern - Load acts into memory for efficient section-level navigation and search

• Detailed document analysis - Metadata, structure, references, and content retrieval

• Content processing - Automatic PDF-to-text and HTML-to-Markdown conversion

• Date calculations - Specialized date utilities for legal document analysis

• System metadata - Keywords, statuses, document types, and institution data

• FastMCP integration - Built with FastMCP framework, flexible transport options

• Async HTTP client - Efficient httpx client with retry logic and connection pooling

• TTL caching - Intelligent response caching with configurable TTL

• Structured logging - JSON and text log formats for easy debugging

• Docker support - Containerized deployment with docker-compose

• Comprehensive documentation - Examples and clear parameter descriptions

Requirements

• Python: 3.13 or higher

• Package manager: uv (recommended) or pip

• Internet connection: Required for accessing Sejm API endpoints

• MCP-compatible tool: Cursor IDE, Claude Code, or other MCP clients

Installation

Using uv (recommended)

Using pip

Using uvx (no installation required)

For quick testing without cloning the repository:

Quick start

STDIO transport (default)

STDIO is the default transport for MCP communication. Start the server and connect from your MCP client:

Configure in your MCP client (e.g., Cursor .cursor/mcp.json):

For Claude Code:

HTTP transport (streamable-http)

Run the server on HTTP with streamable-http transport:

Configure in your MCP client:

Note: The URL must include the /mcp path. FastMCP exposes the streamable-http endpoint at /mcp, not at the root. Using http://localhost:7683 without /mcp results in 404 (Not Found).

Docker

Build and run with Docker:

Or use docker-compose:

Configuration

All settings are configured via environment variables with the LAW_MCP_ prefix:

Example environment configuration:

Tools reference

Law Scrapper MCP provides 13 tools for legal research and analysis:

1. get_system_metadata(category)

Retrieve system metadata for filtering and searching legal acts.

Parameters:

• category (string, default: "all") - Metadata category: "keywords", "publishers", "statuses", "types", "institutions", or "all"

Returns: Keywords, publishers, document types, statuses, and institutions available in the system

Examples:

2. search_legal_acts(publisher, year, keywords, detail_level, status, type)

Search for legal acts with advanced filtering options.

Parameters:

• publisher (string) - Publisher code: "DU" (Dziennik Ustaw) or "MP" (Monitor Polski)

• year (integer) - Publication year (e.g., 2024)

• keywords (string) - Search keywords (AND logic - use multiple searches for OR)

• detail_level (string, default: "standard") - Response detail: "minimal", "standard", or "full"

• status (string, optional) - Document status filter

• type (string, optional) - Document type filter

Returns: List of matching legal acts with metadata

Search note: Multiple keywords use AND logic. Search one keyword at a time for OR behavior.

Examples:

3. browse_acts(publisher, year, detail_level)

Browse all legal acts published in a specific year by publisher.

Parameters:

• publisher (string) - Publisher code: "DU" or "MP"

• year (integer) - Publication year

• detail_level (string, default: "standard") - Response detail: "minimal", "standard", or "full"

Returns: Complete list of acts published in the specified year

Examples:

4. filter_results(result_set_id, pattern, field, type_equals, ...)

Filter and narrow down previously retrieved search/browse/changes results.

Parameters:

• result_set_id (string) - Result set ID from a previous search/browse/changes call (e.g., "rs_1")

• pattern (string, optional) - Regex pattern for text search (supports OR: "podatek|VAT|akcyza")

• field (string, default: "title") - Field to search: "title", "eli", "status", "type", "publisher"

• type_equals (string, optional) - Exact match on document type (e.g., "Ustawa", "Rozporządzenie")

• status_equals (string, optional) - Exact match on status (e.g., "akt obowiązujący", "akt uchylony")

• year_equals (integer, optional) - Exact match on publication year

• date_field (string, optional) - Date field for range filter: "promulgation_date" or "effective_date"

• date_from / date_to (string, optional) - Date range (YYYY-MM-DD)

• sort_by (string, optional) - Sort field: "title", "year", "pos", "promulgation_date", etc.

• sort_desc (boolean, default: false) - Sort descending

• limit (integer, optional) - Maximum results to return

Returns: Filtered results with a new result_set_id for chained filtering

Examples:

5. get_act_details(eli, load_content, detail_level)

Retrieve detailed information about a specific legal act and optionally load its content.

Parameters:

• eli (string) - Act identifier in format "PUBLISHER/YEAR/NUMBER" (e.g., "DU/2024/1")

• load_content (boolean, default: false) - Load act content into Document Store for section reading

• detail_level (string, default: "standard") - Response detail: "minimal", "standard", or "full"

Returns: Act metadata (title, publication date, status, type, etc.), table of contents if load_content=true

Examples:

6. read_act_content(eli, section)

Read content from a specific section of a loaded legal act.

Parameters:

• eli (string) - Act identifier (must be loaded first via get_act_details with load_content=true)

• section (string) - Section to read (e.g., "Art. 1", "Chapter 2", "Preamble")

Returns: Content of the requested section

Workflow note: Must call get_act_details(eli="...", load_content=true) first, then use this tool.

Examples:

7. search_in_act(eli, query)

Search for specific terms within a loaded legal act.

Parameters:

• eli (string) - Act identifier (must be loaded first via get_act_details with load_content=true)

• query (string) - Search term or phrase

Returns: Matching sections with context and location

Examples:

8. analyze_act_relationships(eli, relationship_type)

Analyze legal relationships and references of an act (amendments, references, etc.).

Parameters:

• eli (string) - Act identifier

• relationship_type (string, default: "all") - Type: "amends", "amended_by", "references", "referenced_by", or "all"

Returns: List of related acts and their relationships

Examples:

9. track_legal_changes(date_from, date_to, publisher, keywords)

Track legal changes and new acts within a date range.

Parameters:

• date_from (string) - Start date (YYYY-MM-DD format)

• date_to (string) - End date (YYYY-MM-DD format)

• publisher (string, optional) - Filter by publisher: "DU" or "MP"

• keywords (string, optional) - Filter by keywords

Returns: Legal acts published in the date range

Examples:

10. calculate_legal_date(days, months, years, base_date)

Calculate legal dates with intuitive sign convention.

Parameters:

• days (integer, default: 0) - Days offset (+future, -past)

• months (integer, default: 0) - Months offset (+future, -past)

• years (integer, default: 0) - Years offset (+future, -past)

• base_date (string, optional) - Base date (YYYY, YYYY-MM, or YYYY-MM-DD format, defaults to today)

Returns: Calculated date and relative description

Sign convention: Positive = future, Negative = past

Examples:

11. compare_acts(eli_a, eli_b)

Compare metadata of two legal acts.

Parameters:

• eli_a (string) - ELI identifier of the first act (e.g., "DU/2024/1692")

• eli_b (string) - ELI identifier of the second act (e.g., "DU/2024/1716")

Returns: Comparison of titles, types, statuses, dates, keywords overlap and differences

Examples:

12. list_result_sets()

Display active result sets stored in memory.

Returns: List of result sets with IDs, query summaries, counts, and creation times

13. list_loaded_documents()

Display documents loaded into the Document Store.

Returns: List of loaded documents with ELIs, sizes, section counts, and timestamps

Document Store workflow

The Document Store pattern enables efficient content navigation and search within legal acts:

Workflow steps

1. Load an act - Call get_act_details(eli="DU/2024/1", load_content=true) to load the act into the Document Store

2. Read sections - Use read_act_content(eli="DU/2024/1", section="Art. 1") to read specific sections

3. Search within act - Use search_in_act(eli="DU/2024/1", query="penalty") to find terms

Benefits

• Efficient memory usage (configurable max documents and TTL)

• Fast section-level navigation without refetching

• Search within loaded acts without API calls

• Automatic content processing (PDF→text, HTML→Markdown)

Configuration

• LAW_MCP_DOC_STORE_MAX_DOCUMENTS - How many acts to keep in memory (default: 10)

• LAW_MCP_DOC_STORE_MAX_SIZE_BYTES - Maximum memory usage (default: 5 MB)

• LAW_MCP_DOC_STORE_TTL - How long to keep acts in memory (default: 2 hours)

Project structure

Docker

Dockerfile

The included Dockerfile builds a containerized Law Scrapper MCP server:

Build and run:

docker-compose.yml

Deployment with docker-compose:

Migration guide (v1 to v2)

If upgrading from v1.0.2, note these breaking changes:

What's new in v2.3.0

• 3 new tools — compare_acts, list_result_sets, list_loaded_documents (total: 13 tools)

• Circuit breaker — Protects against cascading failures when Sejm API is unavailable

• Centralized error handling — @handle_tool_errors decorator with error classification and full tracebacks

• asyncio.Lock migration — All stores use asyncio.Lock for proper async compatibility

• Default search limit — Search/browse return max 20 results by default to limit token usage

• Health endpoint — /health for Docker deployments with streamable-http transport

• Polish error messages — All exception messages in Polish for consistent user experience

• Decision tree docstrings — "When to use" / "When NOT to use" for all tools

Development

Setup

Running tests

Code quality

The project follows FastMCP best practices:

• Modular architecture - Separated concerns (models, client, services, tools)

• Type hints - Full type annotation with Pydantic models

• Async throughout - Async/await for all I/O operations

• Comprehensive examples - Minimum 5 examples per tool

• Tagged tools - Organized by category for easy discovery

• Annotated parameters - Clear descriptions for all inputs

• Structured logging - Configurable JSON/text formats

Running the server

Contributing

1. Fork the repository

2. Create your feature branch (git checkout -b feature/amazing-feature)

3. Commit your changes using Conventional Commits format

4. Add tests for new functionality

5. Ensure all tests pass and coverage is maintained

6. Push to the branch (git push origin feature/amazing-feature)

7. Open a Pull Request

Development guidelines

• Follow FastMCP best practices for tool definitions

• Include comprehensive examples and parameter descriptions

• Add appropriate tags for tool categorization

• Write async code throughout

• Add tests for all new functionality

• Update CHANGELOG.md with your changes

• Use English for all code comments and documentation

License

This project is licensed under the MIT License. See the LICENSE file for details.

Author

@numikel

Developed with help from:

And with models:

Legal disclaimer: This tool provides access to Polish legal documents for research purposes. Always consult with qualified legal professionals for legal advice and interpretation of laws.