An astrology API glossary for developers

If you are integrating an astrology API, the hardest part is rarely the HTTP call. It is the vocabulary: ayanamsa, lagna, dasha, sub-lord, divisional chart, and a dozen others that determine whether your request returns the chart you actually meant. This glossary defines the terms a developer meets when wiring up the Vedika API, and maps each one to the request fields and endpoints that control it.

Coordinate and zodiac terms

Everything downstream depends on getting the frame of reference right. These four terms decide which sign a planet lands in before any interpretation happens.

Sidereal vs tropical zodiac

The tropical zodiac anchors 0° Aries to the spring equinox and is the basis of Western astrology. The sidereal zodiac anchors the signs to the fixed-star background and is the basis of Vedic astrology. The two frames currently differ by roughly 24°, which is almost a full sign. The practical consequence: the same birth moment can return a Sun in Leo under one system and in Cancer under the other. Vedika resolves this by running both frames (plus KP) from one API, so you choose the system per request rather than per vendor.

Ayanamsa

The ayanamsa is the measured offset between the tropical and sidereal frames. To get sidereal longitudes you subtract the ayanamsa from tropical longitudes. The catch is that there is no single agreed value — Lahiri (the Indian government standard), Raman, and the KP ayanamsa all differ by fractions of a degree, and the offset itself drifts about 50 arcseconds per year due to precession. A chart computed with the wrong ayanamsa can shift a planet across a sign boundary, so any serious Vedic endpoint must expose the choice.

Ascendant (Lagna)

The ascendant, called lagna in Sanskrit, is the zodiacal degree rising on the eastern horizon at the moment and place of birth. It is the anchor for the whole house framework: house 1 begins at the ascendant. Because it moves roughly one degree every four minutes, the ascendant is the most time-sensitive value in a chart — a birth time off by a few minutes, or a wrong timezone, will frequently land you the wrong rising sign.

Ephemeris

An ephemeris is the underlying table or engine that gives the position of the Sun, Moon, planets, and computed points for any instant. Vedika computes positions with XALEN Ephemeris, its own open-source engine (Apache-2.0, published to crates.io, PyPI, and npm). XALEN is validated against the JPL DE440 planetary ephemeris and the reference swetest tool across a reproducible JPL DE440 benchmark set, with no chart deviating beyond 0.1°. That is astronomical precision — it describes where the planets are, which is independent of how any tradition interprets them.

House and chart terms

Once positions exist, they are organized into houses and derived charts. This is where two practitioners using identical planet positions can still disagree, because the division method is a choice.

House systems

A house system is the rule for slicing the chart into twelve life areas. Whole-sign houses (the classical Vedic default) make each house exactly one sign. Placidus divides by time and is the most common Western system. KP relies on Placidus cusps. The system you pick changes which house a planet falls in near a cusp, which changes the reading — so it is not cosmetic. Vedika exposes whole-sign and Placidus alongside the system selector.

Divisional charts (Varga)

A divisional chart, or varga, is a derived chart that magnifies one domain of life. The Navamsa (D9) is read for marriage and dharma; the Dashamsha (D10) for career; the Saptamsha (D7) for children. Each varga is produced by a fixed mathematical subdivision of a sign, not by AI. A chart endpoint that returns the Shodasavarga set is returning sixteen such derived charts.

Nakshatra

A nakshatra is one of 27 lunar mansions, each spanning 13°20′ of the zodiac. The Moon's nakshatra at birth (the Janma Nakshatra) seeds the Vimshottari dasha sequence and is central to muhurta and matchmaking. Each nakshatra has a ruling planet, which is why the same Moon sign can yield different timelines depending on the exact degree.

Predictive and timing terms

Dasha

A dasha is a planetary period in a predictive timeline. The dominant scheme, Vimshottari, runs 120 years total and assigns each planet a fixed span — for example Venus 20 years, Saturn 19, Sun 6 — with the starting point set by the birth nakshatra. Periods nest: a mahadasha contains antardasha sub-periods, which contain pratyantardasha sub-sub-periods. Interpretation reads the active lord against its sign, house, and aspects. This structure traces to the dasha chapters of the Brihat Parashara Hora Shastra.

Transit (Gochara)

A transit, or gochara, is the current real-sky position of a planet read against the natal chart. Where a dasha is an internal clock fixed at birth, transits are external and shared by everyone alive on a given day. Predictive readings typically combine the two: the active dasha says which themes are live, the transit says when they are triggered.

Yoga

A yoga is a named planetary combination with a defined meaning — for example a Raja Yoga formed by an angular and trinal lord conjoining. Yogas are deterministic: a given placement either satisfies the rule or it does not. Vedika computes its yogas in code rather than asking a model to guess, which keeps the same chart returning the same yogas every time. Yoga definitions are sourced from classical texts such as the Phaladeepika and Saravali.

KP-specific terms

Krishnamurti Paddhati (KP) is a 20th-century refinement of Vedic technique built for precise, often yes-or-no, questions.

Sub-lord

KP subdivides each nakshatra into nine unequal parts proportional to the Vimshottari years, producing a sub-lord for any zodiacal point. Reading the sub-lord of a house cusp or a significator is the deciding step in KP analysis — finer than reading the sign lord or the nakshatra (star) lord alone. The method is laid out in Krishnamurti's KP Readers.

Significator

A significator is a planet that promises a particular house's results, ranked by a defined hierarchy (occupants of the house, the house lord, planets in the lord's nakshatra, and so on). KP horary answers are assembled by checking whether the relevant significators and sub-lords agree.

Mapping the terms to the API

The vocabulary above maps directly onto request fields. The natural-language endpoint takes a question plus structured birth details; the V2 computation endpoints take flat coordinates and return raw chart data you can interpret yourself.

curl https://api.vedika.io/api/v1/astrology/query \
  -H "x-api-key: vk_live_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "question": "Which dasha am I running and what does it mean for my career?",
    "birthDetails": {
      "datetime": "1990-08-15T14:30:00",
      "latitude": 18.5204,
      "longitude": 73.8567,
      "timezone": "Asia/Kolkata"
    }
  }'

For a deterministic chart with positions, houses, and divisional charts — no interpretation — call the V2 computation surface with flat fields:

// Minimal LLM-agnostic fetch; works in any runtime
const res = await fetch("https://api.vedika.io/v2/astrology/chart", {
  method: "POST",
  headers: {
    "x-api-key": "vk_live_xxx",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    datetime: "1990-08-15T14:30:00",
    latitude: 18.5204,
    longitude: 73.8567,
    timezone: "Asia/Kolkata"
  })
});
const chart = await res.json();
// chart.ascendant -> lagna; chart.dashas -> Vimshottari timeline;
// chart.divisionalCharts.D9 -> Navamsa

For long readings, the streaming endpoint /api/v1/astrology/query/stream returns Server-Sent Events so you can render tokens as they arrive. Add "speed": "fast" to a query body when latency matters more than depth. You can exercise all of this without a key on the free sandbox before committing to a plan.

Glossary at a glance

Key facts

• Vedika runs three astrology systems — Vedic (sidereal), Western (tropical), and KP — from one API, plus Jaimini, Tajaka, Lal Kitab, and numerology.
• The API spans 700+ operations across 25 domains (704 enumerated as of June 2026) and supports 30 languages, including 14 Indic languages.
• Positions are computed by XALEN Ephemeris, Vedika's own Apache-2.0 engine, validated against JPL DE440 and swetest with no chart deviating beyond 0.1° across a reproducible JPL DE440 benchmark set.
• Astrological claims trace to classical sources such as the Brihat Parashara Hora Shastra, Phaladeepika, Saravali, and Krishnamurti's KP Readers — yogas and dashas are computed in code, not improvised.
• Plans start at $12/mo (Starter), $60 (Professional), $120 (Business), and $240 (Enterprise), with per-query pricing around $0.01–$0.05; see pricing.
• A free, no-key sandbox lets you test request shapes before integrating.

Choosing where to start

If you want narrative answers, start with the natural-language query endpoint and let Vedika handle term resolution from the question text. If you are building your own interpretation layer or a UI that draws the chart, start with the V2 computation endpoints and treat this glossary as your field reference. Either way, the terms here — ayanamsa, lagna, dasha, varga, sub-lord — are the dials that decide what comes back, so it pays to set them deliberately rather than accept defaults. For deeper integration patterns, the documentation covers authentication, streaming, and the full endpoint catalog.

Frequently asked questions

What is an ayanamsa, and why does an astrology API need it?

Ayanamsa is the angular offset between the tropical zodiac (tied to the equinox) and the sidereal zodiac (tied to the fixed stars). Vedic calculations subtract it from tropical longitudes to get sidereal positions. Because the offset grows over time and several conventions exist (Lahiri, Raman, KP), an API must let you specify it or your sign placements drift by roughly a sign over centuries.

What is the difference between sidereal and tropical zodiacs?

The tropical zodiac fixes 0° Aries at the spring equinox and underlies Western astrology; the sidereal zodiac fixes signs against the stars and underlies Vedic astrology. They differ by about 24° today, so the same birth can show different sign placements. Vedika returns both because it runs Vedic, Western, and KP from one API.

What is a dasha in Vedic astrology?

A dasha is a planetary time period. Vimshottari, the common scheme, gives each planet a span (Venus 20 years, Sun 6 years, and so on) and nests antardasha and pratyantardasha sub-periods. The active lord is read with its house and sign to time events.

What does the KP sub-lord add over a normal house lord?

KP splits each nakshatra into nine unequal Vimshottari-proportioned parts, giving a sub-lord for any point. Reading the sub-lord of a cusp or significator is the deciding factor in KP, which is finer than reading only the sign lord or star lord.