Celestium App — Astrology Engine & Interface

The Problem

A premium natal product needs a real engine behind it. Off-the-shelf astrology APIs are either limited, expensive at scale, or don’t expose the structured data needed for archetypal synthesis. Building the engine in-house meant control over precision, interpretation surfaces, and the long tail of features (astrocartography, transits, human design, tarot) that competitors silo into separate products.

The Solution

A four-module Swift package:

• CelestiumEngine — core astrological computation: natal charts, transit synthesis, astrocartography, human design, tarot deck. Includes a comprehensive interpretation layer (transit angle meanings, traditional astrology audit harness).
• CelestiumApp — the SwiftUI shell that presents readings to the user.
• CelestiumUI — shared design system and view components.
• CelestiumCLI — command-line surface for batch generation and testing.

Tests live alongside each module — including an astrology standards audit that verifies the engine’s output against canonical references.

Status

Engine and app under active development. CLI is operational for batch generation (used by Celestium product fulfillment). UI is iterating.

What This Demonstrates

Building the substrate, not just consuming an API. Owning the engine means the product can evolve without renegotiating with a vendor every time the interpretation surface changes — and means the same engine powers the consumer app, the product fulfillment pipeline, and any future surfaces.