MaStR MCP Server

An MCP server for the Marktstammdatenregister (MaStR) — the German energy market master data register operated by the Bundesnetzagentur (Federal Network Agency). Enables Claude Desktop, Cowork, and Claude Code to directly access the German energy plant registry.

Deutsche Version / German version

Features

21 Tools — 14 SOAP (with credentials), 7 Public (always available)

10 Filter Operators

20 Energy Carriers

All technology keywords are available in English (German aliases also work):

wind, solar, biomass, hydro, storage, geo, mine_gas, sewage_sludge, solar_thermal, pressure_relief_gas/pressure_relief_water, natural_gas, hard_coal, lignite, mineral_oil, other_gases, waste, heat, hydrogen, nuclear.

Without credentials, 7 public tools are available (search power generation, power consumption, gas production, gas consumption, market actors, grid connections + connection test). With credentials (.env), 14 additional SOAP tools are registered (detail queries, filtered searches, catalogs, balancing areas, etc.).

Installation

Prerequisites

• Python >= 3.10

• uv (recommended) or pip

• MaStR web service account (for SOAP API tools, optional): https://www.marktstammdatenregister.de

Step 1: Clone / copy project

git clone https://github.com/UliRCS/mastr-mcp-server.git
cd mastr-mcp-server

Step 2: Install dependencies

With uv (recommended):

uv sync

With pip:

pip install -e .

Step 3: Store credentials in .env

The server automatically loads credentials from a .env file in the project directory (via python-dotenv). This is the recommended approach.

cp .env.example .env
# Edit .env and fill in your values:
# MASTR_USER=SEM123456789012
# MASTR_TOKEN=your-webservice-token-540-chars

.env is excluded via .gitignore — your token will not end up in the repo.

Alternative: You can also set the variables as OS environment variables or in the env block of the Claude Desktop config — OS values take precedence.

Step 4: Test

# Quick test
uv run mastr_mcp_server.py

# Or with the MCP Inspector
npx @modelcontextprotocol/inspector uv run mastr_mcp_server.py

Configuration for Claude Desktop / Cowork

Open the Claude Desktop configuration file:

• Windows: %APPDATA%\Claude\claude_desktop_config.json

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

If .env is in the project directory, you can omit the env block:

{
  "mcpServers": {
    "mastr": {
      "command": "uv",
      "args": [
        "run",
        "--directory", "/path/to/mastr-mcp-server",
        "mastr_mcp_server.py"
      ]
    }
  }
}

Important: Adjust the path under --directory to the actual location on your system.

Configuration for Claude Code

claude mcp add mastr \
  --command "uv" \
  --args "run" "--directory" "/path/to/mastr-mcp-server" "mastr_mcp_server.py" \
  --env "MASTR_USER=SOM123456789012" \
  --env "MASTR_TOKEN=your-webservice-token"

Usage Examples

• "Show me the details of wind turbine SEE966095906064" -> get_unit

• "Find all solar plants in postcode 49074" -> search_power_generation_public({'tech': 'solar', 'postcode': '49074'})

• "Wind turbines between 1200 and 3500 kW in postcode area 23..." -> search_power_generation_public({'tech': 'wind', 'capacity>': 1200, 'capacity<': 3500, 'postcode:': '23'})

• "Wind turbines WITHOUT EEG key" -> search_power_generation_public({'tech': 'wind', 'eeg_key?': ''})

• "All non-wind units in postcode 49074" -> search_power_generation_public({'tech!=': '2497', 'postcode': '49074'})

• "Power-to-Gas hydrogen plants" -> search_gas_production_public({'gas_technology': 'Power-to-Gas (Wasserstoff)'})

• "High-voltage consumers in Bavaria" -> search_power_consumption_public({'bundesland': 'Bayern', 'voltage_level': 'Hochspannung'})

• "Gas consumers with H-Gas that generate electricity" -> search_gas_consumption_public({'gas_quality': 'H-Gas', 'gas_for_power': True})

• "DSOs with more than 100,000 connected customers in Lower Saxony" -> search_actors_public({'function': 'Stromnetzbetreiber', 'dso_large': True, 'bundesland': 'Niedersachsen'})

• "Grid connection points for power generation in postcode 49074 at medium voltage" -> search_grid_connections_public('power_generation', {'postcode': '49074', 'voltage_level': 'Mittelspannung'})

• "Gas feed-in points with H-Gas" -> search_grid_connections_public('gas_production', {'gas_quality': 'H-Gas'})

Project Structure

mastr-mcp-server/
├── mastr_mcp_server.py           # Entry point (imports package, starts server)
├── mastr_mcp/                     # Main package
│   ├── __init__.py               # Package init, conditional tool registration
│   ├── config.py                 # Constants, env vars, technology mappings
│   ├── serialization.py          # SOAP->JSON, MS-AJAX date conversion
│   ├── client.py                 # SOAP client, HTTP fetch, retry helper
│   ├── filters.py                # Filter builder, column mappings, dropdown loading
│   ├── server.py                 # FastMCP instance with instructions
│   ├── tools_soap.py             # SOAP tools (14)
│   ├── tools_public.py           # Public JSON tools (7)
│   └── resources.py              # MCP Resources (4)
├── *_dropdowns.json               # Dropdown ID mappings (5 files, from live API)
├── pyproject.toml                 # Dependencies and metadata
├── .env                           # Credentials (not in git)
└── .env.example                  # Credential template

Security Notes

• The MaStR token is confidential — it belongs in .env, never in the repo.

• The server only performs read operations (no registrations or modifications)

• Daily limit: 100,000 SOAP API calls per user (public JSON is unlimited)

• Only TLS 1.2 connections are accepted

License

MIT