{"openapi":"3.1.0","info":{"title":"Natal Chart Lab astronomy API","version":"1.0.0","description":"Apparent geocentric planet longitudes on the tropical zodiac (Astronomy Engine, checked against NASA JPL Horizons) and the precomputed retrograde table. No key; CORS enabled. Retrograde data is CC BY 4.0: credit Natal Chart Lab.","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"}},"externalDocs":{"description":"Methodology and accuracy check","url":"https://natalchartlab.com/methodology"},"servers":[{"url":"https://natalchartlab.com"}],"paths":{"/api/positions":{"get":{"operationId":"getPositions","summary":"Zodiac positions of the Sun, Moon, planets, mean North Node and mean Black Moon Lilith at an instant","parameters":[{"name":"t","in":"query","required":false,"description":"ISO 8601 UTC instant between 1800 and 2200, e.g. 2026-01-01T00:00Z. Defaults to now.","schema":{"type":"string","format":"date-time"}}],"responses":{"200":{"description":"Positions at the instant","content":{"application/json":{"schema":{"type":"object","required":["time","zodiac","frame","positions"],"properties":{"time":{"type":"string","format":"date-time"},"zodiac":{"const":"tropical"},"frame":{"type":"string"},"source":{"type":"string","format":"uri"},"positions":{"type":"array","items":{"type":"object","properties":{"body":{"enum":["sun","moon","mercury","venus","mars","jupiter","saturn","uranus","neptune","pluto","node","lilith"]},"name":{"type":"string"},"longitude":{"type":"number","description":"Ecliptic longitude in degrees, 0 = 0° Aries"},"sign":{"enum":["Aries","Taurus","Gemini","Cancer","Leo","Virgo","Libra","Scorpio","Sagittarius","Capricorn","Aquarius","Pisces"]},"degree":{"type":"string","description":"Degree within the sign, e.g. 4°12′"},"speed_deg_per_day":{"type":"number"},"retrograde":{"type":"boolean"}}}}}}}}},"400":{"description":"t is not a valid time between 1800 and 2200"}}}},"/api/sky":{"get":{"operationId":"getSkyNow","summary":"The sky right now: positions, the Moon's sign, phase, next sign change and void-of-course windows for seven days, and each planet's retrograde or shadow status","responses":{"200":{"description":"Current sky; times are ISO 8601 UTC to the minute","content":{"application/json":{"schema":{"type":"object","required":["time","positions","moon","retrogrades"],"properties":{"time":{"type":"string","format":"date-time"},"positions":{"type":"array","items":{"type":"object"},"description":"Same items as /api/positions"},"moon":{"type":"object","properties":{"sign":{"enum":["Aries","Taurus","Gemini","Cancer","Leo","Virgo","Libra","Scorpio","Sagittarius","Capricorn","Aquarius","Pisces"]},"degree":{"type":"string"},"phase":{"type":"string"},"illumination":{"type":"number","description":"Illuminated fraction, 0–1"},"next_sign":{"enum":["Aries","Taurus","Gemini","Cancer","Leo","Virgo","Libra","Scorpio","Sagittarius","Capricorn","Aquarius","Pisces"]},"enters_next_sign_at":{"type":"string","format":"date-time"},"void_of_course":{"type":"boolean"},"next_new_moon":{"type":"string","format":"date-time"},"next_full_moon":{"type":"string","format":"date-time"},"void_of_course_windows":{"type":"array","items":{"type":"object","properties":{"sign":{"enum":["Aries","Taurus","Gemini","Cancer","Leo","Virgo","Libra","Scorpio","Sagittarius","Capricorn","Aquarius","Pisces"]},"void_from":{"type":"string","format":"date-time"},"until":{"type":"string","format":"date-time"},"last_aspect":{"type":["string","null"]}}}}}},"retrogrades":{"type":"array","items":{"type":"object","properties":{"planet":{"type":"string"},"status":{"enum":["retrograde","pre-shadow","post-shadow","direct"]},"since":{"type":"string","format":"date-time"},"until":{"type":"string","format":"date-time"},"sign":{"type":"string"}}}}}}}}}}}},"/data/retrogrades.json":{"get":{"operationId":"getRetrogrades","summary":"Every retrograde of mercury, venus, mars, jupiter, saturn, uranus, neptune, pluto beginning 1950–2050, with UTC station times and shadow dates","responses":{"200":{"description":"Column names and rows; times are ISO 8601 UTC","content":{"application/json":{"schema":{"type":"object","properties":{"generated":{"type":"string"},"columns":{"type":"array","items":{"type":"string"}},"rows":{"type":"array","items":{"type":"array"}},"license":{"type":"string"}}}}}}}}},"/data/retrogrades.csv":{"get":{"operationId":"getRetrogradesCsv","summary":"The retrograde table as CSV","responses":{"200":{"description":"CSV with a header row","content":{"text/csv":{}}}}}},"/data/horizons-validation.json":{"get":{"operationId":"getHorizonsValidation","summary":"Our longitudes compared with NASA JPL Horizons at 50 body–time points","responses":{"200":{"description":"Comparison rows and the largest difference in arcseconds","content":{"application/json":{}}}}}}}}