Gene Keys · Human Design · Astrology

The Free Human Design
& Gene Keys API

The most tested, most accurate free Human Design, Gene Keys & Astrology API — Gene Keys–Certified, local-only, and Swiss-Ephemeris-validated. A free connector to your AI, app or website, so you can anchor purpose and meaning in heavenly coordinates you can actually trust.

Try the live API ↓ GitHub ↗
247 passing tests · ~90% coverage 99.4% gate agreement vs official Gene Keys engine 2,000-birth Swiss Ephemeris study No data leaves your machine · MIT
Live in your browser

Cast a chart

Enter a birth moment. It computes locally and returns Gene Keys, Human Design and Astrology — the same JSON the free API serves.

GET /api/chart?…
Type
Authority
Profile
Defined / open centers
Gene Keys spheres
Astrology
Click “Compute chart”, then copy a ready-to-paste prompt for your AI.
Open in ChatGPT ↗
The engine, drawn

Three charts, one moment

The same birth moment rendered three ways — an astrology wheel, a Human Design bodygraph, and the Gene Keys hologenetic profile. Cast a chart above and watch them redraw.

Personality — natal planets Design — 88° solar arc before birth
Personality Design Defined center
Activation Venus Pearl
Proven, not promised

The most tested free Human Design engine

More than good-enough astrology: every gate.line is regression-locked against Swiss Ephemeris, five real third-party charts, and a 2,000-birth study vs the official Gene Keys engine.

247
Passing tests
13 suites · Jest CI on every publish
~90%
Code coverage
Mandala, bodygraph, houses, timezones
99.4%
Gate agreement
Gene Keys spheres vs official engine
95.6%
Line agreement
Same 2,000-birth study · 14 spheres
2,000
Births compared
1600–2200 AD · 30 timezones · 52k placements
125/130
Exact gate.line
5 real charts vs third-party Swiss Ephemeris calc

What the suite covers

  • Swiss Ephemeris golden vectors — gate, line and retrograde locked in profile.test.js
  • Five real reference charts — independent third-party calculator; remainders within one line
  • Official Gene Keys engine study — same birth moments vs genekeysExperimentalV2 (the Hologenetic Profiler)
  • Full bodygraph derivation — activated gates, channels, centers, Type, Authority, Profile
  • Astrology geometry — Ascendant / MC / houses (Placidus, Whole Sign, Equal)
  • Historical IANA timezones — 20th-century DST edge cases regression-locked
  • Midpoint matrix — 325 shorter-arc pairs over the 26 activations

Vs official Gene Keys engine

Hologenetic spheres only (the keys a real profile uses) — median Δ 0.01′ (≈ 0.6″), well inside a Gene Keys line (0.9375°).

MetricGene Keys spheresAll 26 bodies
Median Δ0.01′0.02′
p95 Δ0.17′10.8′
Gate agreement99.4%98.8%
Line agreement95.6%92.6%

Sun & planets typically match Swiss Ephemeris within <1″; Moon ~10″. Pure JS (astronomia VSOP87) by default — optional swisseph backend if you need AGPL precision.

Full accuracy docs on GitHub ↗
One primitive, three lenses

Everything in your profile

A single computeChart() returns three coherent layers of your design.

Gene Keys

The full Hologenetic Profile — gene key and line for every sphere, from Life's Work to your Pearl.

Human Design

Activated gates, defined channels, defined & open centers, plus Type, Authority and Profile — the whole bodygraph.

Astrology

Ascendant, Descendant, MC and IC with Placidus, Whole-Sign or Equal houses — from a location or just your timezone.

Local-only

Pure JavaScript, no native build, no ephemeris files. Nothing about your birth ever leaves the machine.

AI connector

One call returns a ready-to-paste prompt so any AI can interpret your design and walk you into the teaching.

Free & open

MIT licensed, free API, free npm package. The most tested engine of its kind — validated to the exact gate.line against Swiss Ephemeris.

Docs

Use it online or offline

Two ways to use the Free Human Design API — a free hosted REST API for quick online calls, or the npm package for fully local, private computation. Both return the same JSON.

EndpointReturns
/api/chartFull chart — Gene Keys + Human Design + Astrology
/api/genekeysGene Keys spheres only
/api/humandesignHuman Design bodygraph only
/api/astrologyAscendant / MC / houses (needs a location)
/api/midpointsAdvanced — midpoint matrix over the 26 activations
/api/promptA ready-to-paste AI interpretation prompt
/api/timezonesIANA timezone search (?q=bali)

Params: date=YYYY-MM-DD   time=HH:mm   tz=IANA   [lat lng house=placidus|whole|equal midpoints=1]

Install the npm package and compute charts in pure JavaScript — no native build, no ephemeris files, your birth data never leaves your machine.

Install
npm install free-human-design
Usage
const { computeChart } = require('free-human-design');

const chart = computeChart({
  birthdate: '1990-04-16',
  birthtime: '05:35',
  timezone: 'Europe/Brussels',
});

console.log(chart.humanDesign.type);             // "Manifesting Generator"
console.log(chart.humanDesign.profile);          // "6/2"
console.log(chart.geneKeys.spheres.lifeswork.gk); // 13
console.log(chart.astrology.angles.ascendant.sign); // "Aries"
CLI
npx free-human-design --chart --date 1990-04-16 --time 05:35 --tz Europe/Brussels
Questions

Frequently asked

Everything people ask before they cast their first chart.

Is there a free Human Design API?

Yes — this is a free, open-source Human Design API, and the most tested one available. One GET request to /api/humandesign returns the full bodygraph: activated gates, defined channels, defined and open centers, Type, Authority and Profile. No API key, open CORS, MIT licensed.

Is there a free Gene Keys API?

Yes — /api/genekeys returns the complete Gene Keys hologenetic profile: the gene key and line for every sphere, from Life's Work and Evolution to the Pearl. Free and open source.

How accurate are the calculations?

This is the most tested free Human Design engine available: 247 passing tests across 13 suites (~90% coverage). Planetary positions come from the astronomia VSOP87 ephemeris and are validated to the exact gate.line against Swiss Ephemeris — including five real third-party charts (125/130 activations exact). A 2,000-birth deviation study against the official Gene Keys engine shows 99.4% gate and 95.6% line agreement on hologenetic spheres. See the Accuracy section for the full breakdown.

Does my birth data stay private?

Yes. The engine is pure JavaScript and runs entirely on your machine — npm install free-human-design and nothing about your birth ever leaves your computer. The hosted API is stateless and stores nothing.

Can I use it with ChatGPT, Claude or another AI?

Yes — /api/prompt returns a ready-to-paste interpretation prompt containing your full chart, so any AI can read your Human Design and Gene Keys profile and walk you into the teaching.

How do I install it?

npm install free-human-design, then computeChart({ birthdate, birthtime, timezone }) returns Gene Keys, Human Design and Astrology in one JSON. A CLI is included: npx free-human-design --chart --date 1990-04-16 --time 05:35 --tz Europe/Brussels.

Into the teaching
“The calculation is only the doorway. The contemplation is the path.”

Free Human Design gives you the map for free — your Gene Keys, your Human Design, your stars — so you can spend your energy where it matters: living the experiment and contemplating the keys.