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MCP live MCP 2026-07-28 http

CycleCalcs Astronomy

cyclecalcs/astronomy

Astronomy calculations for any place and date: sun and moon rise/set times, planet positions and visibility, Mercury and Venus apparition events, solar and lunar eclipses, lunar phases, dark-sky observing windows, and place lookup. Eleven tools over a 29-endpoint REST API, covering 1700-2200. Streamable HTTP, no install. Tool calls need a CycleCalcs API key from RapidAPI (the Basic plan is free); browsing the tool list needs nothing. Astronomy, not astrology.

Watch this dependency Share evidence report
Uptime
100.0%
5 direct probes · 30d
Response
1160ms
last probe
Tools
12
callable
Resources
0
readable
Prompts
0
available
Primary URL
https://cyclecalcs.com/mcp
Score: 100/100
Handshake verified by our own probe.
pass Answers the MCP handshake 50/50
The handshake and the list calls succeeded on the primary URL.
pass Lists tools, resources or prompts 30/30
12 tools, 0 resources, 0 prompts returned.
pass 3 or more catalogue items 10/10
12 items in total; 3 or more earns these points.
pass Describes itself 10/10
463 characters; more than 30 earns these points.

Tools · 12

astro_sky_today

One-call snapshot of the whole sky for a place and moment: moon phase and illumination, which planets are up and worth looking at, the next eclipse, and (with a location) sun times. Reach for this fir…

astro_sun

The complete solar day for one location: sunrise, sunset, solar noon, day length, civil, nautical and astronomical twilight boundaries, and explicit polar day/night status at high latitudes. Location …

astro_moon

The Moon at an instant or as a daily series: phase name and angle, illuminated fraction, distance, apparent size, libration, bright limb, and the next quarter phases. A location adds rise/set and alti…

astro_moon_phases

Every new moon, quarter and full moon in a window (or the next few from a date): each with its exact instant, distance, apparent size, supermoon classification under both competing definitions, tradit…

astro_positions

Exact positions for up to 20 bodies at an instant or over a time grid: right ascension and declination in both J2000 and of-date frames, ecliptic longitude and latitude, distance, and, with a location…

astro_rise_set

Rise, upper transit, set and lower transit for one body at one location, with an explicit status at extreme latitudes (circumpolar, never rises) instead of missing values. Accepts fixed radec targets.…

astro_eclipses

Solar and lunar eclipses: the next or previous from a date, or all in a range, with type, magnitude, obscuration, Saros series and global geometry. A solar eclipse also carries a computed hybrid flag …

astro_dark_window

The genuinely dark, moonless observing window for a night: astronomical night intersected with the Moon being down, ranked across up to 62 nights with a trend. The right tool for "when should I starga…

observing_windows

Is tonight good for observing here, and when? The clear, dark windows of tonight, and of the next nights the hourly cloud forecast covers, for one place: astronomical night with the Moon down (or up, …

astro_planet_board

All eight planets in one call for a date and optional location: constellation, magnitude, apparent size, elongation from the Sun, morning or evening sky, retrograde state with the next station, rise/s…

astro_planet_events

Dated planet events. For Mercury and Venus, the apparition cycle: inferior and superior conjunctions, greatest eastern and western elongations, peak brightness (a Venus-only event: Mercury's brightnes…

astro_find_place

Resolve a place name to coordinates, region, country, IANA timezone and a stable place_id, or reverse-look-up the nearest places to a lat/lon. Results are GeoNames data (CC BY 4.0); the response carri…

How to use

Claude Desktop or claude.ai: add a custom connector (Customize → Connectors; on Team and Enterprise plans an owner adds it under Organization settings → Connectors) with this server URL: https://cyclecalcs.com/mcp

Cursor or Cline: add to your MCP config:

{
  "mcpServers": {
    "cyclecalcs_astronomy": {
      "url": "https://cyclecalcs.com/mcp",
      "transport": "http"
    }
  }
}