Astral MCP Server

Precision-audited astrology MCP: natal charts, transits, synastry, moon phases. No API key. Exposed over MCP by the astral mcp server, that capability becomes something an assistant can invoke while it works, not something you go and do afterwards.

What it actually does

Adding it to your client

The server ships on npm as astral-mcp, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.

Its toolset

Everything the assistant can do here goes through one of these:

• astral_compute_natal_chart — full natal chart, precision-audited by default
• astral_current_transits — current + upcoming transits to a chart, with moon phase
• astral_synastry — compare two charts (harmony / chemistry / communication / growth)
• astral_moon_phase — moon phase, sign and illumination for any date
• astral_search_birthplace — geocode a place to latitude / longitude / timezone
• astral_demo — worked example chart, no input needed
• astral_capabilities — what this server supports and what it doesn't
• astral_data_inventory — data domains and recommended first calls
• astral_agent_manifest — install + usage rules for agents
• astral_connection_status — health check via a sample chart + dual-engine audit
• structured — same structure, redundant/derivable fields dropped
• summary — only the high-signal essentials (luminaries + Ascendant, chart signature, top aspects)

Caveats

• It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
• With 12 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Astral.
• MCP clients confirm each tool call by default. Leave that on until you have watched what the astral mcp server does with a few real requests.

When to reach for it

This sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Astral's toolset — astral_compute_natal_chart, astral_current_transits, astral_synastry and 9 more — is a fair guide to whether it matches your workflow. It is maintained by davidmosiah; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.