MCP Ephemeris vs Open Ephemeris

In-depth architectural comparison of the MCP Ephemeris and Open Ephemeris MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

Which MCP Server Should You Choose?

Choose MCP Ephemeris when:

• You need dedicated capabilities in the Aerospace & Astrodynamics domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).

Explore MCP Ephemeris Details

Choose Open Ephemeris when:

• You need dedicated capabilities in the Aerospace & Astrodynamics domain.
• You prefer local stdio subprocess transport architecture.
• Your security boundary fits: No auth required (Free / Open Source).

Explore Open Ephemeris Details

Feature & Specification Comparison

Specification	MCP Ephemeris Aerospace & Astrodynamics	Open Ephemeris Aerospace & Astrodynamics
Summary	NASA-validated computed planetary positions for your AI — 19 astrology tools, never hallucinated.	Sub-arcsecond ephemeris and astrology on NASA JPL DE440: natal, transits, eclipses, Human Design.
Category & Scope	Aerospace & Astrodynamics	Aerospace & Astrodynamics

Tools & Capabilities Breakdown

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

{
  "mcpServers": {
    "mcp-ephemeris": {
      "command": "npx",
      "args": [
        "-y",
        "@cosmosos/mcp-ephemeris"
      ]
    }
  }
}

{
  "mcpServers": {
    "open-ephemeris": {
      "command": "npx",
      "args": [
        "-y",
        "@smithery/cli"
      ]
    }
  }
}

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