RentCast API vs HUD open data 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. HUD open data is a set of government datasets about HUD-subsidized multifamily properties (an ArcGIS feature service) and Fair Market Rents (HUD USER API); not a listings API.
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.
- HUD open data: Mapping subsidized apartment buildings and checking rents against HUD Fair Market Rents, not finding a vacant unit.
Side by side
| RentCast API | HUD open data | |
|---|---|---|
| Searches | Active sale and rental listings by city or area with filters, plus 150+ million property records, valuations and market trends. | Locations and program details of HUD-subsidized multifamily properties; Fair Market Rent figures by area. |
| 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. | Property locations and assistance-program attributes; FMR rent figures. No vacancy, availability or asking-rent fields are described. |
| Before the first call | A RentCast account and an API key from the dashboard; no MLS membership or license. | Nothing stated for the ArcGIS endpoint; the Fair Market Rents API needs a HUD USER account and an access token. |
| Free | Developer plan: 50 API calls a month for $0. | – |
| Paid | Foundation plan: $74 a month for 1,000 requests. | – |
| 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 property manager contact is 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. | – |
| Coverage | US nationwide; listings are gathered from public sources, not directly from MLSs. | US |
| MCP server | Official hosted MCP server: https://developers.rentcast.io/mcp | – |
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 $0.
Sources
Every line about another company comes from its own pages. Prices and terms change, so check the source before you rely on one.
RentCast API, read on October 15, 2026:
- rentcast.io/api: “Our pricing plans start with 50 free API calls per month”
- rentcast.io/api: “$ 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.”
HUD open data, read on October 15, 2026:
- catalog.data.gov/dataset/multifamily-properties-assisted: “This dataset denotes HUD subsidized Multifamily Housing properties excluding insured hospitals with active loans.”