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MCP live MCP 2025-11-25 streamable-http

io.github.heavyblotto/caelus-mcp

io.github.heavyblotto/caelus-mcp

34-tool Caelus MCP for validated astrology: charts, transits, Vedic, facts, sky view, synthetic.

Uptime
100.0%
1 direct probes · 30d
Response
895ms
last probe
Tools
35
callable
Resources
3
readable
Prompts
2
available

Tools · 35

natal_chart

A person's birth chart. Requires their exact birth date+time and birthplace (all three: date, lat, lon). Use this — not current_sky — whenever the question is about someone's natal/birth chart. Return…

current_sky

The sky at a moment and place — not tied to any person. Use for "what's the sky/transits right now" or the chart of a non-birth event. Date defaults to now; lat/lon default to 0,0 (geocentric on the e…

sky_view

Where the visible bodies land in a framed photo of the sky, for an image prompt. Give a place, a moment, an aim (compass direction and altitude), a lens, and an image size; get each in-frame body's pi…

sky_view_sequence

A time sequence of sky frames for an animation: the same place, aim, and lens stepped through time. Returns a compact per-frame timeline (instant, twilight, Sun/Moon altitude, Moon phase + bright-limb…

synthetic_validate

Check an authored synthetic celestial system for ill-defined inputs: duplicate body ids, non-positive periods, out-of-range eccentricity, or a dangling observer. Returns `impossible` and a list of pro…

synthetic_positions

Positions of every body in an authored synthetic system at one instant. Three body modes: `placement` (fixed longitude), `periodic` (uniform motion), `kepler` (constant elements). With `observer` set …

synthetic_sky_view

Sky View for a mix of real and synthetic bodies: register the authored system on an ephemeral engine, then frame the visible sky like sky_view. Synthetic bodies can carry render attributes (sizeDeg, m…

transits

Transiting planets vs natal chart: aspects within orb (applying/separating), natal house per transiting body.

synastry

Compare two people's birth charts: inter-chart aspects with orbs, house overlays both ways, plus ranked citable fact atoms and a ready `brief` (synastry/composite ids for auditCitations). Each person …

find_aspect_dates

Exact dates a transiting body makes an aspect, within a range: to a fixed longitude OR to another transiting body. Provide exactly one of target_lon / target_body. Includes retrograde re-hits. Body na…

rectification_grid

Rectification sweep: ASC/MC at each step across a window of UTC hours on one date, with ASC sign-change times. Use when the birth time is unknown and you want candidate times. The sweep runs over wind…

sky_events

Sky events in a UTC date range: rise/set/meridian transits (need lat+lon+body), lunar phases (new/quarters/full), solar and lunar eclipses, stations (body turns retrograde/direct; needs body), zodiac …

planetary_hours

Planetary hours for a moment and place: the unequal hour in effect (its ruler, day/night, hour number 1-24, start/end UTC), the ruler of the planetary day, and the full 24-hour ruler sequence. Hours s…

void_of_course

Void-of-course Moon at a moment: whether the Moon makes no further Ptolemaic aspect to a traditional planet (Sun..Saturn) before it leaves its current sign. Returns the Moon's sign, the UTC time it ex…

returns

Solar or lunar return: the instant(s) a body returns to its natal longitude within a window, plus the full return chart for the first one. The Sun returns about yearly (the solar-return chart for the …

progressions

Secondary progressions (day-for-a-year) and solar-arc directions of a natal chart to a target date. Returns, per body, the secondary-progressed longitude and the solar-arc-directed longitude, plus the…

composite

Relationship charts for two people: the midpoint composite (each body and angle is the shorter-arc midpoint of the two natal positions) and the Davison chart (a real chart cast for the midpoint in tim…

dignities

Essential dignity and sect for the seven traditional planets at a moment and place. Per planet: its sign, any essential dignity (domicile/exaltation/detriment/fall), its weighted essential-dignity sco…

lots

The seven Hermetic lots (Arabic parts) — Fortune, Spirit, Eros, Necessity, Courage, Victory, Nemesis — cast from the Ascendant and reversing direction by sect (a chart is day when the Sun is above the…

profections

Annual and monthly profections (a Hellenistic time-lord technique) at a target date. The natal Ascendant advances one whole sign per year of life; the profected sign's traditional ruler is the lord of…

firdaria

Firdaria (firdariyyat): the Persian/medieval planetary time-lord periods. Life divides into nine major periods totalling 75 years — the seven planets (a day chart starts with the Sun, a night chart wi…

releasing

Zodiacal releasing (aphesis), the Hellenistic time-lord technique from Vettius Valens, released from a Lot (Spirit by default, or Fortune). From the Lot's sign, periods release sign by sign with plane…

directions

Primary (mundane) directions of the seven traditional planets to the four angles (MC, IC, Ascendant, Descendant), and optionally between the planets themselves. The diurnal rotation carries a body to …

nakshatras

The nakshatra (one of the 27 lunar mansions of 13°20′) of each classical point on the sidereal zodiac: the seven traditional planets and the Ascendant (lagna). Per point: the nakshatra name, its pada …

dasha

Vedic dasha periods — planetary time-lord cycles started from the Moon's birth nakshatra. system selects Vimshottari (120-year, the standard), Yogini (36-year, eight yoginis), or Ashtottari (108-year)…

vargas

Parashari divisional charts (vargas): the sign of each of the seven planets and the Ascendant in the requested D-charts — D1 rasi, D2 hora, D3 drekkana, D9 navamsa, D10 dasamsa, D12 dwadasamsa, D30 tr…

yogas

Vedic yogas (planetary combinations) on the sidereal rasi chart: the five Pancha Mahapurusha yogas (Ruchaka, Bhadra, Hamsa, Malavya, Shasha), Gajakesari, Budha-Aditya, and Chandra-Mangala; whether Kem…

aspect_patterns

Classical aspect configurations in a chart: T-squares, grand trines, grand crosses, yods, kites, mystic rectangles, and stelliums by sign and by house. Each is a structured object with the participati…

parans

Parans (paranatellonta): co-angular bodies over the 24 hours from a date at a latitude — every pair of bodies simultaneously on one of the four angles (rising, culminating, setting, anti-culminating) …

chart_signature

A chart's structural signature as plain counts: element, modality, angularity, quadrant, and hemisphere distributions over the bodies; the dominant element, modality, and most-occupied sign; and the c…

chart_facts

A chart's validated facts as ranked, citable atoms for interpretation. Each fact has a stable id (e.g. "aspect:moon~neptune:conjunction"), the bodies it concerns, a salience score (luminaries, angular…

counterfactual_chart

A birth chart, perturbed — a 'what if'. Give a base chart (date+lat+lon) and an edit: `shift_time` (e.g. '1h', '-30m', 'P1D') moves the instant ("born an hour later"), `move_lat`+`move_lon` recompute …

similar_skies

Find when the sky most resembled a reference moment. Builds a feature vector for the reference date's planetary configuration and scans a window for the closest matches by cosine similarity (1.0 = ide…

electional_search

Rank moments in a window for an electional aim. Samples the window and scores each instant by how closely a set of wanted body-to-body aspects is satisfied (tighter and applying aspects score higher),…

cosmic_weather

The mundane sky on a date: the active aspect configurations among the transiting planets (T-squares, grand trines, grand crosses, yods, kites, mystic rectangles, stelliums by sign), any planet station…

Resources · 3

chart-widget

Renders the natal_chart / current_sky payload as a caelus-wheel chart.

ui://widget/chart.html
accuracy

Per-body accuracy: vs Swiss Ephemeris (swiss) and JPL Horizons apparent positions (jpl).

caelus://accuracy
glossary

Machine-readable definitions: aspect angles and default orbs, signs, bodies, the twelve house systems, and essential dignities (domicile/exaltation/detriment/fall).

caelus://glossary

Prompts · 2

rectification_session

Guide a birth-time rectification: sweep candidate ascendants across the day, then test them against dated life events.

natal_reading

Guide a grounded natal reading: compute the chart's ranked fact atoms, then write an interpretation in which every claim cites the atom ids it rests on.

How to use

Add to your Claude Desktop / Cursor / Cline MCP config:

{
  "mcpServers": {
    "io.github.heavyblotto/caelus-mcp": {
      "url": "https://www.ephemengine.com/api/mcp",
      "transport": "streamable-http"
    }
  }
}