Parcel atlas, npm SDK and MCP server

npm SDK, @urbankitstudio/atlas

A typed wrapper around the atlas, bundled offline so your code makes no runtime network call to resolve a county. Look up an endpoint by slug or FIPS, read its searchable fields, and build deep-links into the parcel-lookup tool. Works in Node 18+ and every modern bundler.

npm i @urbankitstudio/atlas

A real example

Every function below ships in v0.5.3. findCountyByFips and findCounty return undefined on a miss rather than throwing, so you can branch on the result.

import { findCountyByFips, listStates, atlas } from "@urbankitstudio/atlas";

// 1. Resolve a 5-digit county FIPS to its parcel endpoint.
const kane = findCountyByFips("17089"); // Kane County, IL
if (kane) {
  const endpoint = kane.endpoints[0];
  console.log(endpoint.url);          // the live ArcGIS REST URL
  console.log(endpoint.searchFields); // [{ name: "PIN", searchable: true }, ...]
}

// 2. Discovery: which states are indexed, and how many counties each.
const populated = listStates().filter((s) => s.populated);
console.log(populated.length, "states");

// 3. Coverage totals are on the bundled atlas root.
console.log(atlas.totals); // { states, counties, endpoints }

// Unknown / malformed input returns undefined. It never throws.

MCP server, for AI agents

The parcel atlas is available as a published npm MCP server you can run in any MCP-capable client with one command:

It exposes four tools: list_counties, find_county, get_parcel_endpoint, and build_owner_query. The server is public and read-only. Your client pays its own LLM-token cost; there is no key to manage.

Claude Desktop config

Open claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/; Windows: %APPDATA%\Claude\) and merge in this block, then restart Claude Desktop.

{
  "mcpServers": {
    "urbankit-atlas": {
      "command": "npx",
      "args": ["-y", "@urbankitstudio/mcp-atlas"]
    }
  }
}

Clients that connect by URL instead of spawning a subprocess can point at the remote HTTP endpoint: https://urbankitstudio.com/api/mcp. It exposes six public discovery tools plus two key-gated actions: enrich_address returns owner, APN, and mailing fields for one address, and radius_ownersreturns every owner parcel inside a radius. enrich_address runs on paid plans or pay-as-you-go and uses one unit when data is released; radius_owners is paid-plans-only and uses one unit per parcel row returned, with a caller-set cap and a count_only preview.

The full MCP server page has the per-tool reference, an example conversation, a curl walkthrough, and setup notes for Cursor and other clients.

Property owner lookup API

The SDK and MCP server hand you the verified county endpoint to query. If you would rather send a US street address and get the owner back directly, the hosted /api/atlas/lookup endpoint is the property owner lookup API on top of the same 155-county atlas. One authenticated GET resolves the address to its county, the parcel endpoint, and the owner / APN / mailing fields that endpoint exposes, the address-to-owner API behind the parcel-lookup tool, and a practical skip-trace API alternative when the owner of record is all you need.

curl "https://urbankitstudio.com/api/atlas/lookup\
?address=100 N Lake St, Aurora, IL" \
  -H "Authorization: Bearer uk_live_..."

{
  "ok": true,
  "matched": true,
  "geocode": {
    "matchedAddress": "100 N LAKE ST, AURORA, IL, 60506",
    "countyName": "Kane",
    "stateAbbrev": "IL",
    "countyFips": "17089"
  },
  "atlas_indexed": true,
  "county": {
    "county_name": "Kane",
    "county_fips": "17089",
    "endpoints": [
      {
        "url": "https://.../MapServer/0",
        "searchable_fields": [
          { "name": "PIN",        "label": "Parcel number (APN)" },
          { "name": "OWNER_NAME", "label": "Owner of record" },
          { "name": "SITE_ADDR",  "label": "Site address" }
        ],
        "sample_query": ".../query?where=PIN='...'&outFields=*&f=json",
        "endpoint_status": "ok"
      }
    ]
  }
}

Anonymous calls work up to 10 a day so you can try the response shape; a free key raises that to 500 a day, and the paid plans add bulk address-to-owner enrichment for whole lists. Owner data comes from each county's own public ArcGIS layer. When a county does not publish owner names, the response says so rather than guessing.

SDK or MCP, which one?