Human Design API: Build HD Apps with 12 Endpoints

🕓 Recorded 2026-04-14, updated 2026-05-09. TS / Python / PHP SDKs are now live on public registries — @astroway/sdk (npm), astroway (PyPI), astroway/sdk (Packagist). Details in changelog.

Human Design has grown from a niche esoteric system in the 1990s to a mainstream personal development framework. Apps like [Human Design App] and platforms with millions of users have normalized it — and developers are asking: how do I calculate a Human Design chart programmatically?

This post covers the technical side: what HD calculations are, which APIs support them, and how to build an HD feature into your app.

Human Design is built on three classical systems:

• Western astrology — planet positions at birth
• I Ching — 64 hexagrams mapped to 64 “gates”
• Chakra system — nine “centers” (energy hubs)

The calculation takes your birth data and produces a bodygraph — a visual chart showing:

• Type (Manifestor, Generator, Manifesting Generator, Projector, Reflector) — your energetic signature
• Strategy — how you make decisions
• Authority — which center you follow for decisions (Sacral, Emotional, Splenic, etc.)
• Profile — line combination (1/3, 4/6, etc.)
• Channels — connections between centers that define your personality
• Incarnation Cross — your life purpose, derived from four key positions

Under the hood, each of the 64 gates corresponds to a range of ecliptic longitude. Your planets’ longitudes at birth map to specific gates (and lines within gates). The “Design” calculation is done for 88° of Sun movement before birth — about 3 months earlier.

Human Design uses two birth moments:

1. Personality — your actual birth time. This is the “conscious” side.
2. Design — when the Sun was 88° before its birth position. This is the “unconscious” side.

Every gate activation belongs to one of these. A full chart has 13 + 13 = 26 activations.

This is what makes HD calculations heavier than a standard astrology chart — you’re effectively calculating two charts.

Most astrology APIs either don’t support HD at all or have shallow support (type + strategy only). Full HD implementation requires:

• 64 gate mappings (lookup table)
• 6 lines per gate (384 total cells)
• 9 centers with defined/open logic
• 36 channels (each connecting two centers)
• Incarnation Cross calculation
• Profile derivation from Sun gate line + Earth gate line (Personality and Design)

APIs that handle all of this are rare. AstroWay API has 12 HD endpoints — the deepest coverage we’ve seen in a commercial API.

Let’s say you’re adding HD to an existing astrology app. Start with the main endpoint:

import { Astroway } from '@astroway/sdk';

const client = new Astroway({ apiKey: process.env.ASTROWAY_API_KEY! });

const hd = await client.humanDesign({
  date: '1990-07-14',
  time: '14:30:00',
  timezoneOffset: 3,
  latitude: 50.4501,
  longitude: 30.5234,
});

console.log(`Type: ${hd.type}`);         // e.g. "Generator"
console.log(`Strategy: ${hd.strategy}`); // e.g. "To Respond"
console.log(`Authority: ${hd.authority}`); // e.g. "Sacral"
console.log(`Profile: ${hd.profile}`);   // e.g. "1/3"
console.log(`Defined channels: ${hd.channels.length}`);

Response shape:

{
  "type": "Generator",
  "strategy": "To Respond",
  "notSelfTheme": "Frustration",
  "authority": "Sacral",
  "profile": "1/3",
  "definition": "single",
  "cross": {
    "name": "Right Angle Cross of the Sphinx",
    "quarter": "Civilization",
    "gates": [1, 2, 7, 13]
  },
  "centers": [
    { "name": "Sacral", "defined": true },
    ...
  ],
  "channels": [
    { "gate1": 34, "gate2": 20, "name": "Channel of Charisma", "type": "Generated" }
  ],
  "personalityActivations": [...],
  "designActivations": [...]
}

Penta is a technique for understanding team dynamics in groups of 3–5 people. It’s rare — most HD calculators don’t offer it. But it’s gold for HR-tech, coaching platforms, and team-building apps.

const penta = await client.hdPenta({
  members: [
    { date: '1990-07-14', time: '14:30:00', timezoneOffset: 3, latitude: 50.45, longitude: 30.52 },
    { date: '1988-03-10', time: '08:15:00', timezoneOffset: 2, latitude: 48.85, longitude: 2.35 },
    { date: '1985-11-22', time: '18:00:00', timezoneOffset: -5, latitude: 40.71, longitude: -74.00 },
  ],
});

console.log(`Penta type: ${penta.type}`);
console.log(`Defined channels in group: ${penta.definedChannels.length}`);

HD charts are sensitive to birth time. A 10-minute error can change the profile (e.g. 1/3 → 1/4). For users who don’t know exact birth time, run sensitivity analysis:

const sensitivity = await client.hdSensitivity({
  date: '1990-07-14',
  time: '14:30:00',
  timezoneOffset: 3,
  latitude: 50.4501,
  longitude: 30.5234,
});

// sensitivity tells you which fields change if time shifts ±5/15/30 min

Use this to warn users: “Your profile might shift at this precision. Consider rectification.”

If you’re building an HD-focused app:

• Basic user: 1 HD chart at signup, cached forever = 50 credits one-time
• Power user: occasional transits + compatibility = ~200 credits/month
• 100 DAU with moderate HD use: ~110,000 credits/month → Starter ($19/mo) easily covers it
• 1,000 DAU: ~150,000 credits/month → Pro ($59/mo)

Compatibility queries are heaviest (100 credits). Cache the result for each user pair forever (results are immutable).

Bodygraph rendering is traditionally done in SVG. The API returns centers + channels data; you render the visual. Example:

function Bodygraph({ hd }: { hd: HDChart }) {
  return (
    <svg viewBox="0 0 400 600">
      {hd.centers.map(c => (
        <polygon
          key={c.name}
          points={CENTER_COORDS[c.name]}
          fill={c.defined ? CENTER_COLORS[c.name] : 'white'}
          stroke="black"
        />
      ))}
      {hd.channels.map(ch => (
        <line
          key={`${ch.gate1}-${ch.gate2}`}
          x1={GATE_COORDS[ch.gate1].x}
          y1={GATE_COORDS[ch.gate1].y}
          x2={GATE_COORDS[ch.gate2].x}
          y2={GATE_COORDS[ch.gate2].y}
          stroke="#d4a84c"
          strokeWidth="3"
        />
      ))}
    </svg>
  );
}

The coordinates are a fixed template (every bodygraph has the same 9 centers and 64 gates in the same positions).

• Human Design API — product page with full endpoint list
• Example: Human Design — detailed /v1/human-design walkthrough
• Quick start — get your free API key (up to 200 HD charts/mo on Free)