Astronomy MCP Server

@cyanheads/astronomy-mcp-server What's in the sky, computed offline - planet and moon positions, rise/set, phases, eclipses, and seasons for any place and time via MCP. STDIO or Streamable HTTP. Its 8 documented tools cluster into astronomy, parallax.

People who work with astronomy, cyanheads and eclipse and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-08-25 · ★ 3 · #18 OF 55 MAINTAINED WEB FRAMEWORK · VERIFIED 2026-09-18

Apache-2.0 · TypeScript servers · how we verify → /methodology

01 · Install Astronomy MCP Server

before you install - you'll need

Set MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL before connecting.

Claude Code

claude mcp add cyanheads-astronomy-mcp-server --transport http https://astronomy.caseyjhand.com/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "cyanheads-astronomy-mcp-server": {
      "url": "https://astronomy.caseyjhand.com/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://astronomy.caseyjhand.com/mcp

transport: streamable-http

endpoint alive - responded to MCP initialize · probed 2026-09-17

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions · remote - your agent's requests go to astronomy.caseyjhand.com

endpoint auth accepted our unauthenticated MCP initialize - no credentials needed to connect

license Apache-2.0 - declared in the repository

npm package @cyanheads/astronomy-mcp-server - published under the repo owner's npm scope (@cyanheads)

registry namespace io.github.cyanheads is GitHub-verified and matches the repo owner

03 · What Astronomy MCP Server can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

What you can build

An agent gets 8 documented tools across astronomy, parallax, including astronomy_get_sky_position, astronomy_get_rise_set, astronomy_get_moon_phase, astronomy_find_events.

Capability map

Tools grouped from the project's README - what Astronomy MCP Server lets an agent do.

Astronomy

7 tools - e.g. Apparent position of one body or named star for an observer and instant - equatorial (RA/Dec), horizontal (alt/az), ecliptic, plus distance, magnitude, angular ; Rise, set, and culmination times for a…

astronomy_get_sky_position · astronomy_get_rise_set · astronomy_get_moon_phase · astronomy_find_events · astronomy_list_visible · astronomy_get_ephemeris…

Parallax

1 tool - e.g. and aberration-corrected for the observer; default elevation 0 m, default time now

Parallax

Latest releases

v0.2.9 · 2026-08-25

mcp-ts-core 0.12 adoption - strict inputs, error-envelope outputSchema, cache hints · Tool calls with an argument key the schema doesn't declare are now rejected by name instead of accepted…

v0.2.8 · 2026-08-18

content[] parity and body-card recovery · astronomy_list_visible tails every numeric field on its per-body scan line, not just distance - a content[]-only client now recovers the same values a structuredContent client…

v0.2.7 · 2026-08-18

Rise/set chronology, stargazing-plan anchoring, and zoneless-UTC time · This release changes existing output for common inputs: the first astronomy_get_rise_set cycle for a body already above the horizon, and any…

04 · Who maintains Astronomy MCP Server

astronomy-mcp-server is maintained by cyanheads. We track 125 MCP servers from cyanheads - 119 actively maintained, 1,816 combined GitHub stars, oldest repo from Dec 2024. Full record: all servers from cyanheads.

05 · Facts

repository: github.com/cyanheads/astronomy-mcp-server
category: web framework - ranked #18 of 55 actively-maintained web framework servers as of 2026-09-18.
release cadence: 10+ releases in the last 90 days (latest 2026-08-25)
registry: io.github.cyanheads/astronomy-mcp-server (active, first published 2026-06-28 · 12 versions)
packages: npm:@cyanheads/astronomy-mcp-server · npm:@cyanheads/astronomy-mcp-server

06 · Astronomy MCP Server FAQ

Is Astronomy MCP Server still maintained?

Yes - as of 2026-09-18, its last commit was 2026-08-25 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

What can Astronomy MCP Server do?

An agent gets 8 documented tools across astronomy, parallax, including astronomy_get_sky_position, astronomy_get_rise_set, astronomy_get_moon_phase, astronomy_find_events.

How do I install Astronomy MCP Server?

Run `npx -y @cyanheads/astronomy-mcp-server`. The README documents 2 environment variables (MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL) to set first. Set MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL before connecting. You can also paste the ready-made client config above.

Does Astronomy MCP Server require authentication?

No - the endpoint accepted our unauthenticated MCP initialize when probed on 2026-09-17; you can connect without credentials.

07 · Alternatives to Astronomy MCP Server

Alternatives to Astronomy MCP Server

Maintained web framework servers if Astronomy MCP Server isn't the fit.

More web framework MCP servers · Gitwand · Source Library · Qrcodly · Aspicio · Inbed

More TypeScript MCP servers · Aviation Weather MCP Server · Biorxiv MCP Server · Brapi MCP Server · Cdc Health MCP Server · Census MCP Server · see all