November 2026
Data Dictionary 2.1 is now the default Listings reference
The Listings API docs now describe RESO Data Dictionary 2.1. The Data Dictionary 1.7 reference stays available for existing integrations, and the Version menu switches between them on the same section.
Clearer token caching rules
The Authentication section now explains that API Gateway caches the authorization result for one hour, so re-authenticating within that hour returns the same token and does not reset its 24 hour expiry.
October 2026
Delete History endpoints
New endpoints list records removed from the Assessor, Deed, Mortgage, Assignment, Release, Pre-Foreclosure, Base Properties, Mortgage Property Aggregate, Sales and Transfer, and Loan data sets, with a dictionary for each.
September 2026
History expansions on base properties
Base property queries can now expand historicalEstimate, taxHistory, salesAndTransferHistory and mortgageHistory.
Delete and flat file details
The Property Data docs now cover how deletes are delivered and what the flat file exports contain.
Points of Interest and Transit Data removed
The Points of Interest and Transit Data sections were removed from the Property Data documentation.
August 2026
Polygon search
Pass a top-level polygon with a WKT POLYGON string of longitude and latitude pairs to return properties that intersect the shape.
Connect an AI client over MCP
New guide for pointing Claude, ChatGPT, Cursor and automation tools at the BaseProperties and Listings MCP servers, using the client ID and secret you already have.
July 2026
Authorization header required on every request
The API is stateless. Requests without an Authorization: Bearer header are rejected with 401 Unauthorized, even after earlier successful calls.
June 2026
request-trace-id header required for media
All media requests must include a request-trace-id header set to your client ID.
May 2026
Census geography on base properties
Base property queries can now return census administrative geography such as county or parish.
April 2026
Schools, school districts and RESO listings in GraphQL
The Property Data API (GraphQL) now documents resoProperties, schools and school districts alongside base properties.
Mortgage Property Aggregate
A new Mortgage Property Aggregate entity and dictionary, with its own delete history.