The decision
If you want to add Human Design chart calculation to your application, you have two paths: build the calculation engine yourself, or integrate an existing API.
Comparison table
| Factor | Build from Scratch | Use Human Design Hub API |
|---|---|---|
| Time to first chart | 4-12 weeks | 30 minutes |
| Astronomical calculation stack | Integrate and maintain a precision astronomy stack | Handled by API |
| Astronomical data files | Download and maintain calculation data files | Not your concern |
| Gate mapping tables | Implement 64 Gate degree ranges | Built into API |
| Center definition logic | Implement 36 Channel activation rules | Automatic |
| Accuracy verification | Test against known charts manually | High-precision chart calculations included |
| Transit calculations | Additional planetary position math | 5 dedicated endpoints |
| Composite analysis | Overlay logic for 2 charts | Single POST request |
| Group Penta | No open-source implementation exists | Exclusive endpoint |
| Ongoing maintenance | Calculation data updates, bug fixes | Included in subscription |
| Cost (year 1) | $10,000-50,000 in developer time | $0-1,200 ($0-99.99/mo) |
When to build yourself
Building your own engine makes sense if:
- You need sub-arc-second precision for research purposes
- You want to modify the fundamental calculation methodology
- You are building a library to sell to other developers
- You have an existing astrology engine and only need the HD mapping layer
When to use the API
The API is the right choice if:
- You want to ship a product quickly
- Human Design calculation is a feature, not your core product
- You need composite, transit, or Group Penta analysis
- You want React visualization components out of the box
- You do not want to maintain ephemeris data files