Core chart data
Charts, houses, aspects, and transits
Generate tropical or sidereal natal charts, houses, aspects, transits, synastry, and structured horoscope signals as server-side JSON.
Explore all calculation APIs78 live calculation APIs · built for trusted backends
R231 is live: 77 standard calculations plus the Pro Nakshatra Timeline are available, with the 500-request Free allowance and globally serial durable jobs.
Build Western, sidereal, and Vedic-oriented applications with documented JPL DE421 calculations. Generate chart data and graphics, search bounded astrological events, create reports, and automate trusted server workflows through one API.
// Run on your server; store the key in ASTROAPI_KEY
const response = await fetch("https://api.cosmicephemeris.com/api/astro/birth-chart", {
method: "POST",
headers: {
"Content-Type": "application/json",
"Authorization": `Bearer ${process.env.ASTROAPI_KEY}`
},
signal: AbortSignal.timeout(20000),
body: JSON.stringify({
date: "2000-01-01",
time: "12:00",
lat: 0.0,
lon: 0.0,
timezone: "UTC"
})
});
if (!response.ok) throw new Error(`Cosmic Ephemeris HTTP ${response.status}`);
const data = await response.json();
console.log(data.chart);
# Run on your server; store the key in ASTROAPI_KEY
import os
import requests
url = "https://api.cosmicephemeris.com/api/astro/birth-chart"
payload = {
"date": "2000-01-01",
"time": "12:00",
"lat": 0.0,
"lon": 0.0,
"timezone": "UTC"
}
headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {os.environ['ASTROAPI_KEY']}"
}
response = requests.post(url, json=payload, headers=headers, timeout=20)
response.raise_for_status()
print(response.json()["chart"])
The Cosmic Ephemeris production platform
Start with established chart endpoints, then add explicitly bounded beta calculations and developer workflows without changing providers.
Start with the zodiac and house system you need, then review the supported features.
Tropical natal charts, planetary aspects, synastry, and transits at a requested instant. Equal and whole-sign houses are included, alongside beta solar-arc directions, secondary-progressed planets and solar/lunar returns.
Select Lahiri, Raman, Krishnamurti, Fagan–Bradley, Yukteshwar, Sassanian, True Chitra, True Revati, True Pushya, Galactic Center at 0 Sagittarius, or Galactic Alignment/Mardyks ayanamsa for sidereal longitudes, signs, chart angles, houses, and Moon nakshatra data.
Build from sidereal charts and nakshatra/pada geometry, with Pro transition timelines for nine bodies. Explore beta D1/D2/D3/D4/D5/D6/D7/D8/D9/D10/D11/D12/D16/D20/D24/D27/D30/D40/D45/D60/D81/D108/D144/D150, Vimshottari through optional Sookshma depth 4, Indian chart SVGs and instant Panchang with explicit conventions. Regional calendars, festivals and complete Jyotish analysis remain outside the current scope.
Chart graphics, Western and Vedic beta APIs
Pratyantardasha inputs and period conventions
Davison relationship chart conventions
Moon phases and iCalendar exports
Planetary ingresses, stations, and exact aspects
Fixed-reference house ingress search
Calculation methodology · Application use cases · About Cosmic Ephemeris · Build an astrology app
Clear answers to the questions developers actually ask.
Free includes 500 standard API requests per UTC calendar month with no credit card required. Tropical and sidereal chart calculations are included.
Cosmic Ephemeris exposes 78 live calculation endpoints: seven established routes and seventy-one bounded beta routes. Coverage includes natal charts, houses, aspects, transits, synastry and structured horoscope signals; chart SVG/PNG; composites, Davison, progressions, solar arcs, returns and lunar nodes; twenty-four Vargas, Vimshottari through optional depth 4, Panchang, Ashtakoota, and Ashtakavarga with opt-in reductions and pindas; Moon phases, planetary events, house ingresses, aspect windows, unified calendars, eclipse and electional searches; bounded electional reliability audits through exact repair-hardening minimax regret; relocation, astrocartography, natal analysis, reports, birth-time sensitivity and six fixed stars; and symbolic numerology arithmetic without predictions. Seventy-seven standard calculations are available on every plan; Nakshatra Timeline requires Pro.
All plans can use server-side API keys, projects, development/staging/production controls, per-key budgets, saved chart inputs, team workspaces, signed job-completion webhooks, deterministic report downloads and MCP access to all 78 live calculations. Durable jobs accept one to ten items from fourteen fixed operations through JSON or bounded NDJSON, with the same scopes, budgets, quotas and one-unit-per-item accounting as synchronous calls.
Cosmic Ephemeris supports tropical calculations for Western astrology and sidereal charts with Lahiri, Raman, Krishnamurti, Fagan–Bradley, Yukteshwar, Sassanian, True Chitra, True Revati, True Pushya, Galactic Center at 0 Sagittarius, or Galactic Alignment/Mardyks ayanamsa. Moon nakshatra/pada data and beta D1/D2/D3/D4/D5/D6/D7/D8/D9/D10/D11/D12/D16/D20/D24/D27/D30/D40/D45/D60/D81/D108/D144/D150, Vimshottari, Indian SVG and instant Panchang calculations support Vedic-oriented applications. Panchang uses an explicit USNO solar-event model and latitude limits; regional calendars, festivals and a complete Jyotish system are not provided.
Equal and whole-sign houses are supported, with opt-in beta Placidus and Porphyry that reject undefined geometry without a fallback. Porphyry is limited to the Houses and natal-SVG endpoints. Public calculation dates run from January 1, 1900 through December 31, 2050. Supply an IANA timezone for local birth times; omitted timezones default to UTC.
Yes. The beta solar-arc endpoint rotates natal planets and Ascendant/MC by the true tropical solar arc, with tropical or sidereal output and synthetic equal or whole-sign houses. It does not calculate physical event charts, converse directions or predictions. Each admitted calculation uses one standard request.
Yes. The beta Vimshottari endpoint returns major periods and Antardasha by default. Depth 3 adds 729 Pratyantardashas; depth 4 adds 6,561 bounded Sookshma periods. It uses a fixed 365.25-day year, supports Lahiri, Raman, Krishnamurti, Fagan–Bradley, Yukteshwar, Sassanian, True Chitra, True Revati, True Pushya, Galactic Center at 0 Sagittarius, and Galactic Alignment/Mardyks ayanamsas, and costs one standard request per admitted synchronous calculation. Other dasha systems and deeper levels are not supported.
Cosmic Ephemeris currently supports Lahiri, Raman, Krishnamurti, Fagan–Bradley, Yukteshwar, Sassanian, True Chitra, True Revati, True Pushya, Galactic Center at 0 Sagittarius, and Galactic Alignment/Mardyks ayanamsas, not every sidereal system offered by other products. The six-star-only CC0 beta is available; asteroid and minor-body calculations are not offered. Separate betas provide Moon-phase calendars, bounded global eclipse geometry and hourly electional filtering. They do not provide local eclipse visibility or paths, crescent visibility, continuous electional guarantees, rankings or advice. Solar/lunar returns find natal-longitude returns, not new or full moons.
You may integrate documented results into your application subject to the Terms; reselling raw API access is not permitted.
Authorization: Bearer <YOUR_API_KEY>
Any language capable of sending HTTPS requests.
Planetary positions use the bundled JPL DE421 ephemeris. House angles and lunar-node fields use documented engine approximations; see the calculation methodology for scope.
Yes. Use Stripe's hosted billing portal to change plans or cancel. Plan changes are prorated, and cancellation takes effect at the end of the current billing period.
API keys are returned once, stored only as one-way SHA-256 hashes, and transmitted over HTTPS. Keep them on your server.
Technology partners
Each partner keeps its own application, accounts, credentials, subscriptions, data, and policies.
Partnered with TimeMatrix
TimeMatrix brings advanced market charting, Gann tools, and financial-astrology research into one browser-based workspace.
Related products. Separate accounts, subscriptions, and policies.
Partnered with FilingSift
FilingSift turns selected debt, liquidity, covenant, waiver, and going-concern disclosures into source-cited, machine-readable changes.
Independent API and data product. Not investment advice.