Nous NOUSAstrology API
Astrology API

Western natal, Vedic, astrocartography, and transits — one astrology API, one endpoint.

A place and a time in. Every chart out. Send a birth moment and place, get back natal charts and house cusps, sidereal kundli and panchanga, a full astrocartography and relocation suite, and transit timing. Positions derive from JPL DE441 — the reference ephemeris — computed directly for the exact moment, not looked up in a table or proxied to a third party.

4
disciplines in one call — western, vedic, astrocartography, transits
250 µs
median full natal chart, single call
JPL DE441
the reference ephemeris — computed directly, <1e-12° cross-check
Built on JPL DE441, the reference ephemeris — computed directly for the exact moment, then cross-checked against Swiss Ephemeris and Astrodienst to under 1e-12°.
Playground

Call the real API

Pick a discipline, then a tab, fill in the inputs, and hit run. Live tabs call the actual gateway. Start with Complete Chart: give a place name and we resolve the coordinates and timezone for you, or switch to Coordinates to pass an exact lat/lon — either way it opens a clean, full read-out on its own page. Every other live tab opens its raw JSON response on its own page, so you can see exactly what each verb returns. The Astrocartography tab is one part of a full relocation suite (see below).

What's in every chart

Not just coordinates — the fields most APIs make you compute yourself

The full chart call returns decision-ready output: the derived fields report generators and interpretation apps normally have to build themselves, plus the bodies serious astrologers ask for and most APIs leave out.

Derived fields, ready to use

  • Chart shape — the overall pattern
  • Planetary dignities — total dignity score
  • Sect — day chart / night chart
  • Part of Fortune — the lot, computed
  • Moon phase
  • Retrograde flags — per body
  • Chart ruler

The points other APIs skip

  • Chiron
  • Ceres, Pallas, Juno, Vesta — the four asteroids
  • Black Moon Lilith — true and mean
  • Lunar nodes — Rahu / Ketu, true and mean
  • Declinations — for every body

Both zodiacs, one call

  • Pass dual=1 with an ayanāṃśa
  • Tropical and sidereal positions back together
  • Western and Vedic from the same birth data
  • 13 house systems · 4 ayanāṃśa

Every field above is a real key in the live chart response. Nothing here is computed on your side.

Astrocartography suite

Full astrocartography as an API

World lines, paran crossings, and local-space bearings — all in the one call — plus place-relative queries almost nobody else exposes.

GET /v1/acg

World lines, parans & local-space

Every planet's rise, set, MC, and IC line across the whole world — plus the paran latitudes where lines cross and local-space azimuth/altitude bearings — for one birth moment, in a single call.

GET /v1/acg/near

Lines near a place

Which planetary lines pass near any chosen point on Earth, and exactly how close, for one birth moment.

GET /v1/acg/cities

Nearest cities to a line

The cities nearest a specific planet's specific angle line — pick the body and the angle.

GET /v1/acg/cities/all

Cities on every line

The nearest cities to every planetary line at once — the whole world's crossings in one response.

Transits & events

Mercury retrograde dates in one call

Every planet's stations, ingresses and events across a year, ready to drop into an app or a notification feed — plus personal transits, chart transits, and lifelong activation windows.

Planetary events for a whole year

  • GET /v1/planet/events — stations, conjunctions, oppositions, elongations, closest approaches
  • /v1/transits/window — every sign or nakshatra ingress across a window

Personal & chart transits

  • /v1/transits — which transiting planet aspects which natal planet, by orb (sidereal)
  • /v1/western/transits — the full transit→natal aspect grid (tropical)

Lifelong activation windows

  • /v1/transits/windows — the ages at which a directed planet aspects a natal planet within orb
The engine

Why it's accurate

No lookup table, no third-party feed. The gold-standard source, computed directly — and reproducible at population scale.

SOURCE

Built on JPL DE441

Positions derive from JPL DE441 — the reference ephemeris professional astronomy and software are built on.

METHOD

Computed directly

Every position is computed from first principles for that exact moment — not looked up in a table, not interpolated, not proxied.

VALIDATION

Cross-checked to <1e-12°

Positions match to under 1e-12 degrees against Swiss Ephemeris and Astrodienst — the exact engines you already trust.

REPRODUCIBLE

Bit-exact at scale

Same input, same bytes out — reproducible across millions of charts and long transit spans. Built for back-testing and research.

Proof

Real numbers, not adjectives

Every figure here is measured on this engine, not a marketing estimate.

250 µs
median latency, full natal chart
13
house systems supported
4
ayanāṃśa systems for sidereal work
<1e-12°
position error vs. DE441 cross-check
CapabilityNOUS Astrology APITypical astrology SaaS APIDesktop astrology software
Disciplines from one endpointWestern, Vedic, astrocartography, transitsusually one, sometimes split into separate productsvaries by product
Median full-chart latency250 µs200–800 msinstant, but not scriptable over HTTP
House systems131–3~20 (library-dependent)
Sidereal (ayanāṃśa) support4 systems, chart and transitoften a separate productvaries by product
Astrocartography suiteACG world lines, parans, local-space bearings, lines near a place, nearest citiesrarely any ACG at allACG in some products
Asteroids, nodes, Chiron, Lilith, declinationsall in the chartusually planets onlyvaries by product
Retrograde & direct stationsevery planet, one callrarely exposedmanual lookup
Tropical + sidereal in one callyes — one flagusually separate requests/productsvaries by product
Source ephemerisJPL DE441, computed directlyinherits an upstream libraryreference-grade
Batch charting runs at 38,000 charts/sec, and a full natal-chart transit scan is a single call — both on high-throughput POST endpoints, available on request.
All verbs

Everything this API does

Grouped by discipline. Every verb is a real call against the same gateway.

Western / Natal

Vedic

Astrocartography

Transits

How it works

Birth time and place in, any chart out

01

Send date, time, place

Year, month, day, hour, minute, latitude, longitude — or a place name, resolved internally. Plain query parameters, no SDK required.

02

Pick a discipline

Western natal, sidereal Vedic, astrocartography, or transits — the same birth data drives every one.

03

Engine computes directly

Positions, cusps, lines, and transit hits are computed from JPL DE441 for that exact moment — including historical time zones and DST, the number-one cause of wrong charts, resolved internally.

04

Get JSON back

Charts, houses, aspects, nakshatras, lines, or transit dates in a flat, predictable response.

One call, not five

Downstream of nothing

Place and time in — nothing else. No geocoder, no timezone API, no sunrise service, no ephemeris to license or maintain. Your world today is roughly five vendors; ours is one call.

Geocoding API Timezone API Sunrise / sunset service Ephemeris to license or open-source (AGPL) No one selling ACG

One NOUS call

Resolve the location, handle historical time zones, compute every chart plus the full relocation suite — from a single endpoint. Stop maintaining calculation code; the peak-hour compute spikes go away and your engineers build product instead.

Self-hosting Swiss Ephemeris today? You carry two costs most teams forget: its commercial license fee, or the AGPL obligation to open-source anything you serve over a network. Our engine is independent — neither one applies to you.

Vedic depth

Regional depth for Indian-market products

Not just a generic sidereal chart. Panchanga returns tithi, karana, yoga, and vara — plus solar maasa, solar rashi, and the Tamil calendar — alongside 4 ayanāṃśa systems, full kundli, and nakshatra with pada.

Panchanga — the daily almanac

  • Tithi, karana, yoga, vara
  • Solar maasa and solar rashi
  • Tamil calendar
  • Nakshatra with pada

Kundli & sidereal work

  • Full sidereal chart — planets and houses
  • 4 ayanāṃśa: Lahiri, Raman, Krishnamurti, Fagan-Bradley
  • Whole-sign and 13 house systems
  • Retrograde flags per body

Nakshatra & ayanāṃśa

  • Nakshatra and pada for any body
  • Ayanāṃśa value for any date, any system
  • Sidereal transits with an ayanāṃśa
Built for developers

Integrated in an afternoon

Plain query parameters over HTTP. No SDK to install, no client library to version. Flat, predictable JSON back — the same response shape across every discipline.

No SDK

Call it with any HTTP client. Nothing to install, nothing to keep in sync with a release cadence.

Query params in

Every input is a plain query parameter — year, month, day, hour, lat, lon. Readable, cURL-able, debuggable.

Flat JSON out

Predictable keys, the same shape across disciplines. Parse once, reuse everywhere.

Usage-based

Pay for calls, not seats. Costs track your actual traffic, not your headcount.

Docs

Example request

GET /v1/chart?year=1990&month=6&day=15&hour=10&minute=0&lat=48.8566&lon=2.3522
{
  "ok": true,
  "fields": {
    "sun": "24°03′ Gemini",
    "moon": "14°14′ Pisces",
    "ascendant": "5°09′ Virgo",
    "mc": "28°02′ Taurus",
    "house_system": "Placidus"
  },
  "raw": "SUN 84.0493 GEM, MOON 344.2370 PIS, ASC 155.1425, MC 58.0349"
}
Use cases

Who this is for

Astrology apps

One integration for natal, Vedic, relocation, and forecast features — no separate vendors to stitch together.

Report generators

Bulk-produce charts, kundli, paran tables, and transit timelines for PDF/print reports at scale.

Compatibility & travel tools

Call two charts and compare them on your end, or rank cities by planetary line in real time as a user adjusts birth data.

Researchers

Reproducible, bit-exact positions across large populations of charts and long spans of transits.

Pricing

Pay for calls, not seats

Usage-based tiers — costs track your actual traffic. One credit is one basic chart; richer calls cost a few credits. Start free and go break the playground before we ever talk money.

Free
$0 / mo
1,500 credits / month
  • Western, Vedic & transits — core data
  • Full DE441 engine: geocode + historical DST
  • Community support
Get started
Starter
$24 / mo
96,000 credits / month
  • Everything in Free + all 12 themed packs
  • Astrocartography lines + Grand Profile
  • Email support
Choose Starter
Scale
$99 / mo
396,000 credits / month
Birth-time rectification + research analytics
  • Everything in Growth
  • 40 requests/sec sustained throughput
  • Direct engineering support
Choose Scale
Enterprise
Let's talk
Custom volume
Full engine, dedicated capacity
  • Dedicated batch throughput
  • Volume & SLA terms
  • White-glove onboarding
Talk to us

Ready to compute a chart?

No signup required to try the playground above.

Try it live
FAQ

Common questions

Is this one API for all four disciplines, or four products?+
One API. Western natal, Vedic, astrocartography, and transits share the same gateway, the same birth-data inputs, and the same flat JSON response shape — you integrate once.
What is the engine actually built on?+
Positions derive from JPL DE441 — the reference ephemeris professional astronomy and software are built on — computed directly for the exact moment, not looked up in a table or proxied to a third party. We cross-check the output against Swiss Ephemeris and Astrodienst to under 1e-12°, so you're not gambling on a new source of truth.
Are results reproducible for back-testing and research?+
Yes — same input, same bytes out. Positions are reproducible and bit-exact across millions of charts and long transit spans, which is what makes population-scale research and back-testing possible.
Do you include Chiron, the asteroids, nodes, and Lilith?+
Yes — the full chart returns Chiron, the four asteroids (Ceres, Pallas, Juno, Vesta), Black Moon Lilith (true and mean), the lunar nodes (Rahu/Ketu, true and mean), and declinations, alongside the standard planets. It also returns derived fields — chart shape, dignities, sect, Part of Fortune, moon phase, and retrograde flags.
What astrocartography techniques do you support?+
A full suite: /v1/acg returns world lines, paran crossings, and local-space compass bearings in one call, and the /v1/acg/near, /v1/acg/cities, and /v1/acg/cities/all routes answer place-relative questions — which lines pass near a place, and the nearest cities to a line. Local-space bearings are rarer than ACG itself. The astrocartography suite is a Growth-and-up feature.
Can I get Mercury retrograde dates?+
Yes — /v1/planet/events returns every planet's notable events across a year in one call: retrograde and direct stations, conjunctions, oppositions, greatest elongations, and closest approaches, each timestamped.
Do you offer sidereal (Vedic) charts?+
Yes — full kundli, panchanga, nakshatra, and ayanāṃśa endpoints, and you can pass dual=1 with an ayanamsha on the natal chart call to get tropical and sidereal positions together. Four ayanāṃśa systems: Lahiri, Raman, Krishnamurti, Fagan-Bradley. Panchanga also returns solar maasa, solar rashi, and the Tamil calendar.
Which house systems are supported?+
Placidus, Koch, Porphyry, Regiomontanus, Campanus, Equal, Whole Sign, Topocentric, Alcabitius, Morinus, Meridian, Horizontal, and Krusinski.
How are pre-1925 timezones and local mean time handled?+
Historical timezone and local-mean-time offsets are resolved from the coordinates and date supplied, including for dates before formal timezone standardization — you don't need to pre-compute UTC yourself. Historical time zones and DST are the number-one cause of wrong charts; that bug just isn't yours here.
Does astrocartography accept a place name, like "Tokyo"?+
Yes — location resolution is built in. Send coordinates directly, or a place name, and it's resolved internally; you don't need a separate geocoding service. Timezone and local-mean-time are derived the same way, from the place and date supplied.
Is there an SDK to install?+
No — it's plain query parameters over HTTP with flat, predictable JSON back. Call it with any HTTP client; there's no SDK or client library to install or version.
Do you support Vimshottari daśā or divisional (varga) charts?+
Not on this gateway today. It covers natal charts, kundli, panchanga, nakshatra, ayanāṃśa, astrocartography, relocation, and transits — daśā periods and varga charts aren't exposed yet. We publish what isn't there rather than let you find out.
About

A precision instrument for the cosmos

The NOUS Astrology API is an independent product: a single endpoint that turns a place and a time into every chart — Western, Vedic, astrocartography, and transits — computed directly on JPL DE441. It's part of the Nous ARK family of independent tools, each sold on its own merits.

Every position is computed directly on JPL DE441 — the reference ephemeris behind the world's observatories — to 0.0001-arcsecond precision, orders of magnitude finer than the truncated ephemerides most services inherit. Cross-check any result against the engines you already trust; you're priced by usage.

Contact

Talk to us

Comparing APIs, running a high-volume workload, or want enterprise terms? Start a conversation — no price gate, just a chat about your use case.