ARES MCP Server

A Model Context Protocol (MCP) server that provides access to the Czech ARES (Administrativní registr ekonomických subjektů) API - the official business registry of the Czech Republic.

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Demo

See the ARES MCP Server in action within Claude Desktop:

The demo shows:

• 🔍 Searching for companies by name (e.g., "AiMingle")
• 📋 Getting detailed company information by IČO
• ✅ Validating IČO numbers
• 🏢 Searching in specific registries
• 📊 Using advanced filters (legal form, CZ-NACE codes, etc.)

Quick Start

1. Install the server:

   git clone https://github.com/yourusername/ares-mcp-server.git
   cd ares-mcp-server
   pip install -e .
   

2. Add to Claude Desktop config:

   {
     "mcpServers": {
       "ares": {
         "command": "python3",
         "args": ["-m", "ares_mcp_server.server"],
         "cwd": "/path/to/ares-mcp-server"
       }
     }
   }
   

3. Restart Claude Desktop and start searching Czech companies!

Features

• Full implementation of ARES API endpoints
• Complex search with multiple filters (IČO, name, address, legal form, CZ-NACE, etc.)
• Registry-specific searches (Public Registry, Trade Registry, Schools, etc.)
• Built-in rate limiting
• Optional authentication support
• Proper Czech naming following the API documentation

Prerequisites

• Python 3.8 or higher
• pip (Python package manager)

Installation

Quick Install

# Clone the repository
git clone https://github.com/yourusername/ares-mcp-server.git
cd ares-mcp-server

# Run automated setup
./run.sh  # macOS/Linux
# or
run.bat   # Windows

Manual Installation

# Create virtual environment
python3 -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

# Install dependencies
pip install -r requirements.txt

# Create configuration
cp .env.example .env

Configuration

Configure the server using environment variables in .env:

# Rate limiting (default: 100 requests per 60 seconds)
ARES_RATE_LIMIT_REQUESTS=100
ARES_RATE_LIMIT_WINDOW=60

# Optional authentication token
ARES_AUTH_TOKEN=your_token_here

# Logging level
LOG_LEVEL=INFO

Claude Desktop Configuration

Add to your Claude Desktop configuration file:

macOS

~/Library/Application Support/Claude/claude_desktop_config.json

Windows

%APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "ares": {
      "command": "python3",
      "args": ["-m", "ares_mcp_server.server"],
      "cwd": "/path/to/ares-mcp-server"
    }
  }
}

Available Tools

1. vyhledat_ekonomicke_subjekty

Main search tool - Search economic entities using complex filters

Parameters:

• start (optional): Starting position (default: 0)
• pocet (optional): Number of results (default: 20, max: 200)
• razeni (optional): Sort order array ["ICO", "OBCHODNI_JMENO_DESC", etc.]
• ico (optional): Array of IČO numbers to search
• obchodniJmeno (optional): Business name
• sidlo (optional): Address filter object
  • kodCastiObce: District code
  • kodObce: Municipality code
  • textovaAdresa: Text address search
  • etc.
• pravniForma (optional): Array of legal form codes
• financniUrad (optional): Array of tax office codes
• czNace (optional): Array of CZ-NACE activity codes (max 5)

2. najit_ekonomicky_subjekt

Get detailed information about a specific economic entity

Parameters:

• ico (required): IČO number (8 digits)

3. vyhledat_v_registru

Search in a specific registry

Parameters:

• registry (required): Registry code
  • vr: Veřejné rejstříky (Public Registers)
  • res: Registr ekonomických subjektů (Economic Entities)
  • rzp: Registr živnostenského podnikání (Trade Licensing)
  • nrpzs: Národní registr poskytovatelů zdravotních služeb (Healthcare)
  • rpsh: Registr politických stran a hnutí (Political Parties)
  • rcns: Registr církví a náboženských společenství (Churches)
  • szr: Společný zemědělský registr (Agricultural)
  • rs: Registr škol (Schools)
  • ceu: Centrální evidence úpadců (Bankrupts)
• Plus same search parameters as main search

4. najit_v_registru

Get entity from specific registry by IČO

Parameters:

• registry (required): Registry code
• ico (required): IČO number

5. validovat_ico

Validate IČO format and check existence

Parameters:

• ico (required): IČO to validate

6. vyhledat_ciselniky

Search codebooks and nomenclatures

7. vyhledat_adresy

Search standardized addresses

8. vyhledat_notifikace

Search notification batches

Example Usage in Claude Desktop

Once configured, you can interact with ARES data directly in Claude Desktop. Here are some common use cases:

🔍 Basic Company Search

Ask Claude: "Search for companies with name containing 'Microsoft' in ARES"

Claude will use:

vyhledat_ekonomicke_subjekty with:
- obchodniJmeno: "Microsoft"
- pocet: 10

📊 Get Company Details

Ask Claude: "Get details for company with IČO 26168685"

Claude will use:

najit_ekonomicky_subjekt with:
- ico: "26168685"

✅ Validate IČO

Ask Claude: "Is IČO 26168685 valid?"

Claude will use:

validovat_ico with:
- ico: "26168685"

🏭 Industry-Specific Search

Ask Claude: "Find all restaurants in Prague"

Claude will use:

vyhledat_ekonomicke_subjekty with:
- czNace: ["56"]  # Restaurants and food service
- sidlo: { "nazevObce": "Praha" }
- pocet: 50

📋 Search Multiple Companies

Ask Claude: "Get info for companies with IČO 26168685 and 00000019"

Claude will use:

vyhledat_ekonomicke_subjekty with:
- ico: ["26168685", "00000019"]

🏢 Registry-Specific Search

Ask Claude: "Search for software companies in the trade registry"

Claude will use:

vyhledat_v_registru with:
- registry: "rzp"
- obchodniJmeno: "software"

Development

Project Structure

ares-mcp-server/
├── ares_mcp_server/
│   ├── __init__.py
│   ├── server.py           # Entry point
│   ├── server_v3.py        # Main server implementation
│   ├── api_client_v3.py    # ARES API v3 client
│   └── tools_v3.py         # Tool definitions
├── tests/
├── examples/
├── requirements.txt
├── pyproject.toml
└── README.md

Running Tests

source venv/bin/activate
pytest tests/

API Documentation

This server implements the official ARES API. For detailed API documentation, see:

• ARES Swagger UI
• ARES Website
• API Base URL: https://ares.gov.cz/ekonomicke-subjekty-v-be/rest

Changelog

v0.3.0 (2025-07-04)

• Complete rebuild based on ARES API v3 specification
• Tool names now match API endpoints (Czech names)
• Proper parameter structure matching API documentation
• Support for all search filters including address components
• Added registry-specific search endpoints
• Added utility endpoints (codebooks, addresses, notifications)

License

MIT License

Support

For issues or questions:

• Create an issue on GitHub
• Check the ARES API documentation

Acknowledgments

This server integrates with the Czech ARES API provided by the Ministry of Finance of the Czech Republic.