gridpin for Node.js

Offline geocoder: an address to coordinates and back, from one local file per country (a "sheet"). No API key, no rate limit, no query leaves the machine. The same engine as the gridpin CLI, Python package, R package and DuckDB extension, through its C interface.

const { Geocoder, sheets } = require('gridpin');

const sheet = await sheets.fetch('us');          // once: download, check size and SHA-256 against the signed release
const g = new Geocoder(sheet);
g.geocode('1600 Pennsylvania Ave NW, Washington, DC', { k: 1 });
// [{ lat: 38.8976751, lon: -77.036547, precision: 'house', street: 'PENNSYLVANIA Avenue Northwest',
//    housenumber: '1600', commune: 'Washington', postcode: '20500', confidence: 0.95, weak: false, ... }]
g.geocodeMany(['10 Downing St', null, '350 5th Ave, New York']);   // one list per row, input order kept
g.reverse(38.8977, -77.0365);
g.close();

• weak: true marks an answer the engine itself says needs a check before use (city level, low confidence, or a fuzzy street with middling confidence). An exact house on an exact street is never weak.
• Sheets live where the CLI and gridpin-mcp keep them: GRIDPIN_HOME, else $XDG_CACHE_HOME/gridpin, else ~/.cache/gridpin. sheets.list(), sheets.where('us'), sheets.verify('us'); GRIDPIN_OFFLINE=1 forbids downloads.
• geocodeMany runs on the calling thread: for large batches, use a worker thread.

Countries, data sources and licenses: https://gridpin.dev. Engine: Apache-2.0. Sheet data: OpenStreetMap contributors (ODbL), Overture Maps and national open address sources.