Swiss Ephemeris
@dm0lz
Swiss Ephemeris MCP Server is a Model Context Protocol (MCP) server that provides precise astrological calculations—including natal charts, planetary transits, synastry, and solar return charts—using the Swiss Ephemeris. It exposes tools for LLMs and AI agents to retrieve planeta
Overview
What is Swiss Ephemeris?
The Swiss Ephemeris MCP Server is a Model Context Protocol server that provides astronomical calculations using the Swiss Ephemeris library. It calculates planetary positions, houses, chart points, and asteroids for any date and location, targeting developers and astrologers integrating ephemeris data into AI tools.
How to use Swiss Ephemeris?
Install the swetest command locally (required for Claude Desktop), then configure the server via Claude Desktop’s MCP settings or run manually with npx github:dm0lz/swiss-ephemeris-mcp-server. Four main tools are provided: calculate_planetary_positions, calculate_transits, calculate_solar_revolution, and calculate_synastry, each accepting ISO8601 datetime and geographic coordinates.
Key features of Swiss Ephemeris
- Calculates positions for Sun, Moon, and all classical planets
- Includes true and mean lunar nodes
- Supports asteroids: Chiron, Ceres, Pallas, Juno, Vesta, Lilith
- Computes 12-house Placidus system
- Returns Ascendant, Midheaven, IC, Descendant, South Node, Part of Fortune
Use cases of Swiss Ephemeris
- Generate accurate birth charts for any date, time, and location
- Compare natal chart positions with current transits
- Compute solar return charts for a given year
- Analyze relationship compatibility via synastry aspects
FAQ from Swiss Ephemeris
What prerequisites are needed for local use?
The Swiss Ephemeris swetest command must be installed; the README provides a script to compile and copy it from the official source.
How do I configure Swiss Ephemeris with Claude Desktop?
Add the server entry to Claude Desktop’s MCP configuration JSON, using npx as the command and the GitHub repo as the argument.
What transport modes does Swiss Ephemeris support?
Stdio is the default mode for Claude Desktop; HTTP mode can be enabled by setting the environment variable MCP_HTTP_MODE=true, useful for web integration via ngrok.
Where can I find the Swiss Ephemeris library and source code?
The library is available at https://www.astro.com/swisseph/ and the server repository at https://github.com/dm0lz/swiss-ephemeris-mcp-server.
Does Swiss Ephemeris require an internet connection for calculations?
No; calculations are performed locally using the installed Swiss Ephemeris binaries – no network dependency is mentioned.
