Ascendant

Ascendant is a Python package for calculating Vedic astrology charts, Vimshottari Dashas, Yoga combinations, and Ashtakavarga values.

It uses Swiss Ephemeris through pyswisseph and supports typed configuration for ayanamsa and house-system defaults.

Installation

Ascendant requires Python 3.11 or later.

python -m pip install astro-ascendant

pyswisseph is installed as a package dependency. No separate flatlib installation is required.

Quick start

Create an Ascendant instance with the local birth time, UTC offset, and geographic coordinates:

from ascendant import Ascendant

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    utc="+5:30",
    latitude=28.6139,
    longitude=77.2090,
)

# Rasi chart (D1)
chart = astro.get_chart(division=1)

# Detected Yoga combinations
present_yogas = [
    yoga for yoga in astro.get_yogas() if yoga["present"]
]

# Vimshottari Dasha
dasha_timeline = astro.get_dasha_timeline()
current_dasha = astro.get_current_dasha()

# Ashtakavarga and Sarvashtakavarga
ashtakavarga = astro.get_sav()
sarvashtakavarga = ashtakavarga["sarva"]

By default, Ascendant uses the Lahiri ayanamsa and Whole Sign houses.

Features

• Sidereal planetary and house calculations using Swiss Ephemeris
• Divisional charts, including D1, D9, D10, and other supported Vargas
• Vimshottari Mahadasha and Antardasha timelines
• Current Dasha lookup for a supplied date
• Registered Vedic Yoga evaluation with structured results
• Bhinnashtakavarga, Sarvashtakavarga, Shodhana, and Shodhya Pinda
• Typed, immutable calculation configuration

Configuration

Override the defaults for an individual chart:

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    utc="+5:30",
    latitude=28.6139,
    longitude=77.2090,
    ayanamsa="Krishnamurti",
    house_system="Porphyry",
)

Or configure application-wide defaults:

from ascendant import (
    Ascendant,
    AscendantConfig,
    Ayanamsa,
    HouseSystem,
    configure,
)

configure(
    AscendantConfig(
        ayanamsa=Ayanamsa.LAHIRI,
        house_system=HouseSystem.PORPHYRY,
    )
)

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    utc="+5:30",
    latitude=28.6139,
    longitude=77.2090,
)

Explicit Ascendant arguments take precedence over configured defaults, which take precedence over the package defaults. Each instance captures an immutable configuration snapshot when it is created.

Use get_config() to inspect the configured defaults and reset_config() to restore Lahiri and Whole Sign. Unsupported constructor values raise ValueError.

Supported ayanamsas

• Lahiri
• Lahiri_1940
• Lahiri_VP285
• Lahiri_ICRC
• Raman
• Krishnamurti
• Krishnamurti_Senthilathiban

Supported house systems

• Whole Sign
• Placidus
• Equal
• Equal 2
• Porphyry

Result shape

Ascendant returns regular Python dictionaries and lists. For example, every Yoga result contains:

{
    "id": "gajakesari",
    "name": "GajaKesari",
    "present": True,
    "strength": 0.9,
    "details": "Jupiter in house 4 and Moon is in 1",
    "type": "Positive",
}

Use present to select detected combinations and retain details when presenting or interpreting a result.

Documentation

The repository includes guides for:

• Divisional charts
• Dasha systems
• Yoga combinations
• Configuration

Development

Clone the repository, create the local environment, and use the documented Make targets:

make help
make test
make typecheck
make lint

Swiss Ephemeris accuracy cases live in tests/test_swiss_ephemeris_accuracy.py.

Agent skills

The repository also contains an optional Ascendant agent plugin. It is not required to use the Python package.

npx skills add thaletto/ascendant

Codex users can install the bundled plugin from the repository marketplace:

codex plugin marketplace add https://github.com/thaletto/ascendant.git --ref main
codex plugin add agent@ascendant