Arcgis Loudoun

What Arcgis Loudoun does

Arcgis Loudoun MCP server exposes Loudoun County, Virginia open geospatial data through MCP. The underlying sources are ArcGIS Feature Services and Map Services covering areas such as parcels, addresses, zoning, and public works. An AI client can use the server to locate relevant datasets, understand a layer's structure, and retrieve matching records.

The integration is unofficial and is not affiliated with, endorsed by, or published by Loudoun County or its upstream GIS provider.

How it works

The normal workflow begins with search_datasets. Give it a keyword, such as parcels or zoning, and it returns matching dataset names, summaries, record counts, owners or organizations, and service URLs. Those URLs are then used with the other tools.

layer_info describes a selected layer before querying it. Its response includes field names and types, geometry type, total records, and service capabilities. query_layer retrieves rows from a Feature Service or Map Service layer. It accepts a SQL-like where expression, a comma-separated out_fields list, ordering, a result limit, and an offset. Results contain attributes and geometry. To inspect a sample, use where="1=1" with out_fields="*".

Setup and configuration

The Arcgis Loudoun MCP server can be connected through the hosted Pipeworx endpoint:

{
  "mcpServers": {
    "arcgis-loudoun": {
      "url": "https://gateway.pipeworx.io/arcgis-loudoun/mcp"
    }
  }
}

The hosted connection also exposes shared Pipeworx meta-tools in addition to the three Arcgis Loudoun tools. Its initialize response is the authoritative source for the tools available at connection time. The gateway can route broader questions through ask_pipeworx.

For a local connection, run the package as a stdio MCP server:

{
  "mcpServers": {
    "arcgis-loudoun": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-arcgis-loudoun"]
    }
  }
}

The local mode requires no Pipeworx account and exposes only this pack's tools. The hosted endpoint can also be called over HTTP without an MCP client. The documented examples state that no account is needed for the first calls.

Tools and capabilities

• search_datasets: find Loudoun County GIS datasets by keyword.
• layer_info: inspect schema, geometry, record totals, and capabilities.
• query_layer: retrieve filtered, ordered, paginated records and geometry.
• Use service URLs returned by search_datasets as inputs to the inspection and query tools.
• Query with selected output fields instead of requesting every field when a narrower response is sufficient.

Limitations and notes

Arcgis Loudoun MCP server is limited to the data exposed by Loudoun County GIS ArcGIS services. Queries require a service URL, normally obtained from search_datasets, and the returned fields and capabilities depend on the selected layer.

The hosted pack endpoint lists shared gateway tools alongside the pack's own tools; the standalone stdio package does not.