gridpin-mcp — offline geocoding for AI agents

An MCP server that lets an agent geocode addresses with GridPin: one memory-mapped file per country, read on your machine. No API key, no rate limit, and no query leaves the machine. The only network step is downloading a country sheet once, verified against the signed GridPin release.

Countries (release v0.4.0): Brazil, France, Germany, Italy, Netherlands, Serbia, Spain.

Add it to an agent

Claude Code:

$ claude mcp add gridpin -- uvx gridpin-mcp

Any client that reads an mcpServers config (Claude Desktop, Cursor, ...):

{ "mcpServers": { "gridpin": { "command": "uvx", "args": ["gridpin-mcp"] } } }

Tools

Tool	What it does
list_countries	covered countries, sheet sizes, which are downloaded
download_sheet	fetch one country sheet (32-677 MB) once, verify its SHA-256; the only tool that uses the network
geocode	address text -> ranked candidates with lat, lon, precision, confidence
reverse	coordinates -> nearest indexed addresses with distance_m
batch	up to 1000 addresses of one country per call, in input order

Results are the same as the GridPin CLI, Python and DuckDB return. Treat street or city precision as approximate.

Download a sheet without MCP

$ pip install gridpin-mcp
$ gridpin-fetch fr          # prints the path, e.g. ~/.cache/gridpin/v0.4.0/france.bin

import gridpin
from gridpin_mcp import sheets

path = sheets.download("fr")   # no-op when already downloaded
gridpin.Geocoder(str(path)).geocode("1 rue de la Paix, Paris", 1)

Sheets go to $GRIDPIN_HOME, else $XDG_CACHE_HOME/gridpin, else ~/.cache/gridpin. Sizes and SHA-256 of every sheet are pinned in the package from the signed release attestation; a download that does not match is discarded.

License

Apache-2.0. Sheet data: see attributions.