Mapsmith MCP server

MapSmith

Ask a question about your data. Get an analysis — and the record that proves it.

Most GIS servers hand an agent a tool to run. MapSmith takes the question, works out the analysis — usually several operations, in an order that has to be right — validates the plan before a single file is touched, runs it, and leaves a record of every step that somebody else can check afterwards without rerunning anything.

Try it

Point any MCP client at MapSmith (one JSON block) and ask, in your own words:

Which parcels lie within 1.5 km of the river and sit at 120 m or lower? Give me the mean

elevation and the ground area of each.

That is five operations, two coordinate systems and forty-eight checks. What actually happens is below — the plan, the step that gets rejected for reading something a later step produces, the CRS decision behind every metric step, and an answer you can work out on paper before MapSmith sees the files. That rejection is structural, and so is every other one: a plan that is well formed and answers the wrong question runs instead, which is measured and written down further down this page.

The operations are executed by GeoPandas, DuckDB Spatial, exactextract and Whitebox Workflows — never by the model that asked for them. Every dataset lands on disk next to a lineage manifest: inputs with checksums, the exact parameters, the CRS decisions and why, engine versions, and the deterministic checks that ran on the result.

mapsmith.dev — a real terrain analysis and the manifest that came with it. Both are build products: the figure is rendered from GeoTIFFs MapSmith writes, so the page cannot drift from what the software does.

The manifest is a specified format, not MapSmith's private output: JSON Schema, a toolchain-free validator, a conformance suite, and a hundred-line emitter that never imports MapSmith. Records carry specversion, and CI validates real MapSmith output against the spec's own validator. The specification is archived and citable as 10.5281/zenodo.22205213. The names MapSmith puts in a record beyond the ones the specification defines — every extension check name, and every extension field in crsdecisions with the reason it is not a synonym of a key the specification already has — are listed in docs/manifest-vocabulary.md, generated from the source rather than maintained by hand.

Shortened. The full README is on GitHub.