game.modules.get("kg-cities").api:

Function	What it does
cityOf(scene)	A city scene's { city, era, year, bounds, ... }, or null.
projector(scene)	Lat/lon to scene pixels (and back) for any city scene.
transit(cityId, era)	A city's rapid transit for an era: track, lines, stations.
addLandmarks(fn)	Add landmarks to city maps. fn(cityFlag) returns landmark-like entries (KG Transit's airports use it).
generateCity(cityId, { era, year, area, at, view })	Make a city scene without the dialog. area is "core", "metro" or "auto".
sceneCovering(cityId, { lat, lon, era })	The smallest existing scene of a city whose map covers a point.
cities()	The cities the module knows.

Hook: kgCities.airport is called with { airport, scene } when the GM clicks an airport landmark.

• npm test (Node 20 or later) runs the tests.
• tools/era-preview.html draws a city's era outside Foundry, served by python tools/serve.py.
• The data is built by the tools in tools/ (landmarks, eras, transit) from OpenStreetMap through Nominatim and Overpass. See the notes at the top of each tool.
• node tools/release.mjs <version> builds a clean release in dist/.