---
title: "How to Query County Parcel Data by API | Developer Guide | Realie"
description: "Step-by-step guide on how to query U.S. county parcel records, APNs, parcel boundaries, and assessor data by REST API, CLI, or MCP server."
canonical: https://www.realie.ai/info/how-to-query-county-parcel-data-by-api
---

# How do I query county parcel data by API?

By Realie · Published 2026-08-13 · Updated 2026-10-20

## Quick Answer

To query county parcel data by API, send an HTTP GET request to Realie’s property endpoints with your target state, county, parcel ID (APN), or street address, authenticated with a Bearer API key. You receive normalized JSON containing parcel boundaries, owner records, assessor valuations, sale history, and zoning across 3,100+ U.S. counties.

### Summary

Querying county parcel data traditionally required navigating thousands of separate county assessor and recorder portals, each with different parcel identifier (APN) formats and data schemas. A property data API resolves that fragmentation into a single endpoint. You pass a parcel ID, street address, or geographic coordinates and receive normalized property records as JSON. For coding agents and CLI workflows, Realie also provides a command-line tool and an MCP server for direct IDE querying in Claude and Cursor.

## Querying by State, County, and Parcel ID (APN)

The most direct lookup is by Assessor Parcel Number (APN). Because APN formats vary across counties (some use dashes, others use leading zeroes), Realie normalizes parcel identifiers while preserving the raw county APN in the payload. To query, pass the state, county name, and parcel ID to the `/api/public/property/parcelId` endpoint.

The API returns parcel boundary polygons, land square footage, building area, current assessed value, tax status, and legal description in a single payload.

## Querying by Address or Location Radius

If you do not have the exact APN, you can query by street address or geographic location coordinates. Address lookups (`/api/public/property/address`) parse and standardize street lines against county tax rolls. Location lookups (`/api/public/property/location`) use spatial indexing to return parcel records near latitude and longitude coordinates within a specified radius.

Property search and location endpoints return result pages of up to 100 properties. Address and parcel ID lookups return a single property. Set pagination and measure response times for your actual workload.

## CLI and AI Agent Workflows (MCP)

Developers and AI agents do not need to write raw HTTP requests manually. The Realie CLI provides terminal-native lookups with `--json` output for shell scripts. For AI coding assistants like Claude Code, Cursor, and VS Code, the Realie MCP server enables agents to fetch county parcel records directly during code generation.

## Sources

- [Realie parcel ID lookup](https://docs.realie.ai/api-reference/v3/property/parcel-id-lookup)
- [Realie plans and token limits](https://docs.realie.ai/api-reference/pricing)
- [Realie MCP setup and authentication](https://docs.realie.ai/realie-mcp-server)

## Frequently asked questions

### What parameters are required to query by parcel ID?

You need the state, county name, and the county parcel identifier (APN). Realie handles formatting and hyphen variations automatically.

### Does the API return parcel boundary polygons?

Yes. Parcel boundary geometry is returned alongside building, owner, tax, and zoning attributes in the same JSON object.

### Can AI agents query county parcel data directly?

Yes. Supported MCP hosts can call Realie’s property tools after authentication and account setup. The CLI also supports JSON output for scripts and agents. Follow the current MCP or CLI setup guide.

### How fast are parcel API responses?

Response time depends on the endpoint, request, network path, and load. Measure representative lookups from your application’s region and compare percentiles against your response-time budget.

## Related Questions

- [What is a real estate data API?](https://www.realie.ai/info/what-is-real-estate-data-api)
- [Where can I search county parcel data?](https://www.realie.ai/info/county-parcel-data-search)
- [What is parcel boundary data, and how is it different from assessor data?](https://www.realie.ai/info/parcel-boundary-data)
- [How do I integrate a real estate API?](https://www.realie.ai/info/real-estate-api-integration)
- [How do I connect Realie to Claude?](https://www.realie.ai/info/realie-for-claude)
- [How do I connect Realie to Cursor?](https://www.realie.ai/info/realie-for-cursor)
- [What is the Realie MCP server?](https://www.realie.ai/info/realie-mcp-server)