Astrology MCP Tool

A Python-based astrology calculation tool using Swiss Ephemeris for use with MCP servers and local LLMs.

Features

• Natal Chart Calculation: Calculate complete birth charts with planetary positions, houses, and angles
• Planetary Positions: Get current positions of all planets including Mercury through Pluto
• Aspect Calculations: Calculate planetary aspects (conjunction, square, opposition, trine, sextile)
• Transit Analysis: Track transiting planets and their aspects to natal positions
• Progressions: Solar arc progressions for forecasting

Supported House Systems

• Whole Sign (default) - Each house corresponds to a full zodiac sign
• Placidus, Equal House, Koch, Porphyry, and Regiomontanus available

Installation

Using a Virtual Environment (Recommended)

# Create and activate a virtual environment
python -m venv .venv
source .venv/bin/activate

# Install dependencies
pip install -r requirements.txt

System-wide Installation (Not Recommended)

# Install dependencies globally
pip install -r requirements.txt

Swiss Ephemeris Setup

Swiss Ephemeris requires ephemeris files for accurate calculations. Download the free ephemeris files:

1. Visit https://www.astro.com/swisseph/
2. Download sweph_01.zip through sweph_06.zip
3. Extract to a directory (e.g., ~/ephe)

The ephemeris files will be automatically detected or you can set the path explicitly.

Usage

Basic Example

from astrology.charts.chart import calculate_natal_chart
from datetime import datetime, timezone

# Create a chart for July 20, 2024 at 14:30 in New York
chart = calculate_natal_chart(
    birth_datetime=datetime(2024, 7, 20, 14, 30),
    latitude=40.7128,
    longitude=-74.0060
)

# Access chart data
print(f"Sun: {chart.get_planet_sign('SUN')} {chart.get_planet_degree('SUN')}°")
print(f"Ascendant: {chart.ascendant.sign_name} {chart.ascendant.degree_in_sign}°")

# Get planetary positions
for planet, position in chart.planets.items():
    print(f"{planet.name}: {position.longitude.sign_name} {position.longitude.degree_in_sign}°")

# Get house positions
for planet, house in chart.house_positions.items():
    print(f"{planet.name} is in House {house}")

With Timezone Support

The library handles timezone-aware datetimes automatically. For accurate results, include timezone information in your datetime strings:

from datetime import datetime, timezone, timedelta

# PDT (UTC-7) - California daylight saving time
birth_dt = datetime(1984, 5, 10, 20, 44, tzinfo=timezone(timedelta(hours=-7)))
chart = calculate_natal_chart(
    birth_datetime=birth_dt,
    latitude=34.0211,
    longitude=-118.3965
)

# Or use ISO format with timezone offset
chart = calculate_natal_chart(
    birth_datetime=datetime.fromisoformat("1984-05-10T20:44:00-07:00"),
    latitude=34.0211,
    longitude=-118.3965
)

Note: Without timezone info, the library assumes input is in local time and converts it to UTC. For the most accurate results, always include timezone information.

Using with Any MCP Client

The server uses the Model Context Protocol (MCP) and can be integrated with any MCP-compatible client.

Quick Start:

1. Copy mcp.json from this project to your MCP client's configuration directory
2. Restart or reload your MCP client

Manual Setup:

# Activate virtual environment first
source /path/to/astrology-mcp/.venv/bin/activate

# Run the server
python -m astrology_mcp_server.main

The server communicates via stdio, so any MCP client that supports stdio transport can use it.

Available tools:

• get_current_time - Get the current UTC date and time
• calculate_natal_chart - Calculate a complete birth chart (birth_datetime with timezone recommended)
• get_planet_positions - Get current planetary positions
• calculate_aspects - Calculate planetary aspects between chart objects
• calculate_transits - Get current transits to a natal chart
• get_houses - Get house positions for planets

Important: For accurate natal charts, provide birth datetime with timezone.

Project Structure

astrology-mcp/
├── src/
│   ├── astrology_mcp_server/
│   │   └── main.py            # MCP server entry point
│   └── astrology/
│       ├── __init__.py
│       ├── core/
│       │   ├── calendar.py    # Date/time handling
│       │   ├── ephemeris.py   # Planet positions
│       │   └── aspects.py     # Aspect calculations
│       ├── charts/
│       │   └── chart.py       # Natal chart calculation
│       ├── transits/
│       │   └── transit.py     # Transit calculations
│       └── progressions/
│           └── solar_arc.py   # Progression calculations
└── tests/

Development

# Ensure virtual environment is activated
source .venv/bin/activate

# Run tests
python -m pytest tests/

# Install in development mode
pip install -e .

# Run example natal chart (with your birth data)
python my_natal_chart.py

Troubleshooting

Incorrect Chart Results

If your chart shows incorrect planet signs or house positions:

1. Check timezone handling: Ensure your datetime has proper timezone info

   from datetime import datetime, timezone, timedelta
   
   # Include timezone offset for accurate conversion to UTC
   dt = datetime.fromisoformat("1984-05-10T20:44:00-07:00")  # PDT
   
   chart = calculate_natal_chart(
       birth_datetime=dt,
       latitude=34.0211,
       longitude=-118.3965
   )
   

2. Verify ephemeris files: Make sure Swiss Ephemeris files are downloaded and accessible

3. Check house system: Verify you're using the correct house system (default is Whole Sign)

License

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

Note: This project uses Swiss Ephemeris, which is available under a dual license (AGPL or Commercial). See the LICENSE file for full details and attribution requirements.

Using with LM Studio

LM Studio is a popular interface for running local LLMs and integrating MCP servers.

Setup:

1. Copy mcp.json from this project to your LM Studio MCP config directory (typically ~/.lmstudio/mcp.json)
2. Restart LM Studio

Example configuration:

{
  "mcpServers": {
    "astrology": {
      "command": "/path/to/astrology-mcp/.venv/bin/python",
      "args": [
        "-c",
        "import sys; sys.path.insert(0, '/path/to/astrology-mcp/src'); import astrology_mcp_server.main; astrology_mcp_server.main.main()"
      ]
    }
  }
}

Available tools in LM Studio:

• get_current_time - Get the current UTC date and time
• calculate_natal_chart - Calculate a complete birth chart (birth_datetime with timezone recommended)
• get_planet_positions - Get current planetary positions
• calculate_aspects - Calculate planetary aspects between chart objects
• calculate_transits - Get current transits to a natal chart
• get_houses - Get house positions for planets