ATTOM Property API vs Realie Property Data API for AI agents
ATTOM Property API is a REST API for US property records: ownership, sales history, valuations (AVM and rental AVM), mortgages, schools, crime and neighborhood data. Realie Property Data API is a US property data API (REST, CLI and MCP) for parcel lookup, property search, owners and comparables; its docs describe property records, not MLS listings.
The short answer
- ATTOM Property API: Deep public-record and valuation data on any US property, rather than finding homes currently on the market.
- Realie Property Data API: Cheap, agent-friendly lookups of US parcel and owner records, not finding homes for sale or rent.
Side by side
| ATTOM Property API | Realie Property Data API | |
|---|---|---|
| Searches | Properties by address, parcel number, ATTOM ID or latitude/longitude; the docs describe last sales, sales history and valuations, not active for-sale or rental listings. | Properties and parcels by address, parcel ID, location or whole areas such as counties. |
| Returns | JSON or XML property records with characteristics, ownership, sale history, AVM values and area data. | Property and parcel records with owner details and comparables. |
| Before the first call | A trial sign-up to receive an API key; production plans through ATTOM. | A Realie account, an API key from the dashboard, and a payment method on file before sending API requests. |
| Free | 30-day free trial with an API key. | Free plan: $0 a month with 25 tokens a month. |
| Paid | Not stated on its pages | Tier 1: $50 a month for 1,250 tokens. |
| Acting on a result | Nothing: no agent, landlord or listing contact fields are described. | Nothing: no agent or landlord contact is described (it has owner tools, not listing contacts). |
| Limits on keeping or showing results | Use of data is governed by a separate license agreement that is not published on the site. | Not stated on its pages |
| Coverage | US, 160+ million properties. | US nationwide property data. |
| MCP server | ATTOM MCP Server (access arranged through ATTOM): https://www.attomdata.com/solutions/delivery/mcp-server/ | Official MCP server: https://app.realie.ai/api/mcp (OAuth sign-in) |
Where Openpath fits
Openpath has no homes listed yet. Owners and landlords can list a home for rent or sale on Openpath today, free, and agents will find it through the same search as jobs and businesses. Get listed.
Questions people ask
What do I need before I can use ATTOM Property API?
A trial sign-up to receive an API key; production plans through ATTOM.
Is ATTOM Property API free?
30-day free trial with an API key.
What do I need before I can use Realie Property Data API?
A Realie account, an API key from the dashboard, and a payment method on file before sending API requests.
Is Realie Property Data API free?
Free plan: $0 a month with 25 tokens a month.
Sources
Every line about another company comes from its own pages. Prices and terms change, so check the source before you rely on one.
ATTOM Property API, read on October 15, 2026:
- attomdata.com/solutions/property-data-api: “Sign up for a free 30-day trial to receive an API key and explore ATTOM’s extensive property data”
- attomdata.com/solutions/property-data-api: “Covering 160+ million U.S. properties and 99% of the U.S. population”
- attomdata.com/solutions/property-data-api: “ownership information, lat/long, square footage, loan types, sales history, sales comps, crime, schools and more”
- api.developer.attomdata.com/docs: “return information pertaining to the most recent sale of a property or list of properties”
- attomdata.com/solutions/property-data-api: “The ATTOM MCP Server provides AI-native access to ATTOM Intelligence through the Model Context Protocol (MCP).”
- attomdata.com/solutions/delivery/mcp-server/how-it-works: “Access is governed, permissioned, and centrally managed”
- attomdata.com/terms-of-use: “subject to the terms of a separate license agreement”
Realie Property Data API, read on October 15, 2026:
- docs.realie.ai/api-reference/pricing: “$0 / Month ... 25 Tokens / Month”
- docs.realie.ai/api-reference/pricing: “$50 / Month ... 1,250 Tokens / Month”
- docs.realie.ai/api-reference/faq: “Add a payment method from Billing before sending API requests.”
- docs.realie.ai: “accessing nationwide property data programmatically”
- docs.realie.ai/api-reference/property-data: “A flexible way to paginate through large areas (such as entire counties) to collect all relevant data.”
- docs.realie.ai/realie-mcp-server: “https://app.realie.ai/api/mcp”