RentCast API vs ATTOM Property API for AI agents
RentCast API is a self-serve REST API for US property records, value and rent estimates, market data, and active sale and rental listings. 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.
The short answer
- RentCast API: The quickest self-serve way to search active US rentals and for-sale homes with agent contacts, without MLS paperwork.
- ATTOM Property API: Deep public-record and valuation data on any US property, rather than finding homes currently on the market.
Side by side
| RentCast API | ATTOM Property API | |
|---|---|---|
| Searches | Active sale and rental listings by city or area with filters, plus 150+ million property records, valuations and market trends. | 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. |
| Returns | Listing records with address, coordinates, property type, beds, baths, size, price or rent, status, days on market, MLS name and number, history, and listing agent and office. | JSON or XML property records with characteristics, ownership, sale history, AVM values and area data. |
| Before the first call | A RentCast account and an API key from the dashboard; no MLS membership or license. | A trial sign-up to receive an API key; production plans through ATTOM. |
| Free | Developer plan: 50 API calls a month for $0. | 30-day free trial with an API key. |
| Paid | Foundation plan: $74 a month for 1,000 requests. | Not stated on its pages |
| Acting on a result | Listings include the listing agent's and listing office's name, phone, email and website; no landlord contact is described. | Nothing: no agent, landlord or listing contact fields are described. |
| Limits on keeping or showing results | The API terms allow storing API data in your own systems and redistributing it only as the license section permits; no attribution is required. | Use of data is governed by a separate license agreement that is not published on the site. |
| Coverage | US nationwide; listings are gathered from public sources, not directly from MLSs. | US, 160+ million properties. |
| MCP server | Official hosted MCP server: https://developers.rentcast.io/mcp | ATTOM MCP Server (access arranged through ATTOM): https://www.attomdata.com/solutions/delivery/mcp-server/ |
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 RentCast API?
A RentCast account and an API key from the dashboard; no MLS membership or license.
Is RentCast API free?
Developer plan: 50 API calls a month for $0.
What do I need before I can use ATTOM Property API?
A trial sign-up to receive an API key; production plans through ATTOM.
Is ATTOM Property API free?
30-day free trial with an API key.
Sources
Every line about another company comes from its own pages. Prices and terms change, so check the source before you rely on one.
RentCast API, read on October 15, 2026:
- rentcast.io/api: “Our pricing plans start with 50 free API calls per month”
- rentcast.io/api: “$ 74 Per Month”
- rentcast.io/api: “Active sale and rental listings across the country.”
- developers.rentcast.io/reference/introduction: “To get started, create a RentCast account to access your API dashboard and generate your first API key.”
- developers.rentcast.io/reference/introduction: “We have nationwide coverage for most residential properties and select commercial property types in the US”
- developers.rentcast.io/reference/property-listings: “the names and contact information of the listing agent, the listing office or broker”
- developers.rentcast.io/reference/property-listings: “we do not retrieve our property listing data directly from the MLS”
- rentcast.io/terms-api: “and (v) to incorporate and store the API Data within your internal systems”
- rentcast.io/terms-api: “neither use of the RentCast API nor use of the API Data requires attribution”
- developers.rentcast.io/reference/ai-tools: “The RentCast API MCP server is hosted at https://developers.rentcast.io/mcp.”
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”