geoprims
Exact, cited math for maps, flight, drones, and surveying. It runs on your device.
Density altitude before a flight. Ground sample distance for a drone survey. A traverse closure, a UTM conversion, an H3 cell, sunrise at a field site. geoprims answers questions like these in a plain sentence, then shows how it got there.
- For people: a fast, free website. The answer comes first, with a map or diagram and a "How we got this" panel showing the formula with your numbers and its sources.
- For AI agents: a local MCP server that runs the same calculators and returns the same results, byte for byte. See mcp/README.md.
Why trust it
- Accurate. Reference methods, not shortcuts: Karney geodesics rather than haversine, checked against GeographicLib, PROJ, H3, and published worked examples.
- Cited. Every result names its source, edition, and section. The build fails if a source goes out of date.
- Honest. Assumptions like datum, true vs. magnetic north, and rules of thumb show up as warnings, not fine print. Tools that pass full verification are marked stable; the rest say experimental.
- Private. No ads, accounts, tracking, or server-side math. Your inputs never leave your device.
What it covers
Geodesy, navigation, geometry, aviation, drones, surveying, spatial indexing, raster and terrain, time, and units — with guided workflows that chain the calculators end to end, and explainers for the concepts behind them.
Progress
Live at geoprims.com since September 23, 2026, and still growing. The plan and specs live in openspec/changes/.
Building it
You need rustup, binaryen's wasm-opt, and Node 22 or newer.
npm run build
node mcp/server.mjs
To contribute, start with AGENTS.md.
Disclaimer
geoprims is a planning and education aid. It is not certified for navigation and is not a legal survey. Check operational values against official sources, your aircraft's POH/AFM, and current regulations.
License
MIT
