geoprimsField-grade geospatial math

Licenses

What geoprims is built from, and the attribution each licence asks for.

geoprims itself is MIT. Its source is at github.com/clay-good/geoprims, and the verification report lists the digest of every module in this release.

Data shipped with the site

Every dataset is self-hosted, with its SHA-256 checked before it is used. None is fetched from a third party at run time.

DatasetIssuerLicense
EGM96 geoid, 15-minute grid
EGM96 geoid model by NGA and NASA; 15-minute grid from GeographicLib (C. F. F. Karney).
National Geospatial-Intelligence Agency (EGM96); grid packaged by GeographicLibPublic domain (US Government work); GeographicLib packaging MIT
International Geomagnetic Reference Field, 14th generation
IGRF-14, International Association of Geomagnetism and Aeronomy.
IAGA Working Group V-MODFree to use with attribution (IAGA)
NADCON5 first-step grids: each region's old datum to NAD 83
NADCON5 by the National Geodetic Survey (NOAA); grids from PROJ-data.
National Geodetic Survey, NOAA; GeoTIFF packaging by the PROJ projectPublic domain (US Government work)
World Magnetic Model 2025
World Magnetic Model 2025, NOAA NCEI and BGS.
NOAA NCEI and British Geological SurveyPublic domain (US Government work)

Fonts and the base map

Build dependencies

None of these ship to your browser as themselves; they build the static files this site serves.

PackageVersionLicense
@astrojs/svelte9.0.1MIT
astro7.3.3MIT
axe-core4.13.0MIT
playwright1.62.1MIT
svelte5.57.0MIT

The Rust core and the MCP server have no third-party runtime dependencies. The MCP server is plain Node with none at all.

Left out on purpose

Some datasets people ask for are not here, and will not be. The reason matters more than the absence:

what3words
Its address grid is proprietary and its licence forbids reimplementation, so there is no way to compute it here and show the work.
Enhanced Magnetic Model (EMM)
Its high-resolution coefficients are far larger than the World Magnetic Model for a difference almost no practitioner needs, and it would push the offline download past its budget.
Copyrighted design tables (AASHTO, ASTM, and similar)
Reproducing the tables would infringe. Tools that need a value from one cite the table and take the value as an input instead.
Commercial basemap tiles
Every tile request would tell a third party where you are looking. The map is drawn from public-domain Natural Earth data served from this site.