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)

Tool	API	Auth	Description
get_unit	SOAP	Yes	Full unit details + EEG + CHP + permit + storage in one call
search_power_generation_soap	SOAP	Yes	Filtered search for power generation (all 20 energy carriers, postcode, capacity)
get_actor	SOAP	Yes	Market actor details by MaStR number
get_api_quota	SOAP	Yes	Daily API quota (used / limit)
get_recent_changes	SOAP	Yes	Delta sync: changes since date (EEG, CHP, permit, location, storage)
search_power_consumption_soap	SOAP	Yes	Filtered search for power consumers (postcode, state, status, etc.)
search_gas_production_soap	SOAP	Yes	Filtered search for gas production (capacity, postcode, etc.)
search_gas_consumption_soap	SOAP	Yes	Filtered search for gas consumers (capacity, postcode, etc.)
search_actors_soap	SOAP	Yes	Filtered search for market actors (function, role, postcode, etc.)
get_location	SOAP	Yes	Location details incl. linked units + grid connection points
get_catalog_values	SOAP	Yes	Catalog/enum values (legal form, manufacturer, etc.) by category ID
get_catalog_categories	SOAP	Yes	List all available catalog categories
get_balancing_areas	SOAP	Yes	Balancing areas (Y-EIC codes, control areas), optionally by DSO
get_grid_connection	SOAP	Yes	Grid connection points for a unit (voltage level, location, co-located units)
search_power_generation_public	JSON	No	Power generation units (27 filter keys)
search_actors_public	JSON	No	Market actors (23 filter keys)
search_power_consumption_public	JSON	No	Power consumption units (29 filter keys)
search_gas_production_public	JSON	No	Gas production / gas storage (30 filter keys)
search_gas_consumption_public	JSON	No	Gas consumption units (30 filter keys)
search_grid_connections_public	JSON	No	Grid connection points & locations (4 types, 12-20 filter keys)
get_local_time	SOAP	No	Connection test (always available)

10 Filter Operators

Suffix	Operator	Description
(none) / =	eq	Equal (default)
!=	neq	Not equal
%	ct	Contains
!%	nct	Does not contain
:	sw	Starts with
$	ew	Ends with
>	gt	Greater than
<	lt	Less than
?	null	Is NULL
! / !?	nn	Is NOT NULL

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