In 2022, ATTOM began work to expand the data made available via ATTOM API. This is part of an ongoing process to enhance our data offerings, standardize the data provided via our API and improve its operational efficiency.

  • Consolidation of the data sources used across the company following various acquisitions. Where choices were available, we chose the best source. In most cases, this will lead to a significant improvement in the amount of data, its accuracy, and timeliness.
  • Movement of these into ATTOM Cloud to simplify the process of making the data available via API and allow us to expand the options we make available to customers in the future.
  • The adoption of a standard geocode used by other ATTOM products to identify geographical areas such as flood zones, neighborhoods, counties, and school districts.
  • A new endpoint is being added to the Area API which provides boundary definitions for most of the boundaries included as part of our Area and Community data. In addition, two endpoints are being added to the Area API to assist with migrating to the new geocodes.

This is a major change and will cause disruptions to some of our existing customer's applications. We estimate that less than 10% of our existing customers will be impacted by the changes. For those that are potentially impacted, we have assembled migration kits to help ease the process of transitioning to the new versions of the ATTOM API endpoints. The following is a summary of those changes.

Endpoints Affected

Changes are being made to almost all endpoints. The following endpoints have been identified as having a high probability of requiring changes to the applications that call them.

Area API

Community API


Property API

If your applications do not use the above endpoints, there should be no need for any immediate changes. You may want to familiarize yourself with the enhancements we are making for future projects.

Data Source Changes

The following APIs have new data sources that have been added to ATTOM Cloud:

The following APIs are using the same data source, but the data source has been moved to ATTOM Cloud:

Most of the data provided in ATTOM API V4 is now being sourced from ATTOM Cloud. This should ensure a greater level of accuracy in the data as well as provide consistency with data your company may source from ATTOM Cloud, ATTOM LIst, or Bulk File delivery of property data.

New Endpoints

Boundary Details

Defines the boundary for most areas supported by our new geocoding system in GeoJSON format.

Location Lookup

Given the name of an area and a geography type, this endpoint will return a list of all areas (including the geocodes) with matching names.

Legacy GeoId Lookup

Given an old geocode (geoid), this endpoint will return the new geocode (geoIdV4)

Geocode Changes

Search Criteria

Most API endpoints will accept a geocode as a search parameter to restrict the results to just those geocodes provided. The V4 APIs all require a new geocode (geoIdV4) to be provided. This change affects the following APIs:

API Results

Most of the ATTOM APIs provide geocodes as part of the JSON/XML output. To maintain compatibility, the existing geocode (geoid) will continue to be provided but will have very limited use. The new V4 APIs will also provide a new code (geoIdV4). The APIs affected are:

For further information, see - Geocodes

Area API

The area PI provides endpoints used to make conversions between property ids, points, latitude/longitude, and geocoded into matching geocoded. These endpoints have been converted to work with the new geocoded (geoIdV4).

Breaking Changes

  1. Any Area API endpoint that makes use of geocodes as a search parameter is considered breaking changes as these now require the use of the new GeoIdV4 parameter. All of these calls should be upgraded to V4 asap.
  2. Any calls to Area API endpoints that make use of returned geocoded should be considered breaking changes. The code should be updated to process the values for geoIdV4 returned.
  3. All Area API endpoints have been rewritten. We encourage our customers to retest their own applications to ensure no regression errors have gone undetected.

Community API

The Community API provides access to community data such as Climate, Crime, Demographics, and Natural Hazards. This data is provided at various levels of geography as specified by the geocodes requested.

Breaking Changes

  1. All calls to the Community API are considered breaking changes because of changes to the data source and the adoption of new geocodes. As a result, ATTOM strongly recommends remediating all calls made to the Community API to upgrade to V4.
  2. Community API V4 will not support V1 tokens. If your company is still using a V1 Community API token, it will be necessary to have a new token issued.

For further information see Upgrading to Community API V4


The POI API makes use of Points of Interest data.

  1. At this time, we have not identified any changes that will have an impact on the existing POI API endpoints

Property API

The Community API provides access to property data such as Addresses, Property Characteristics, Building Permits, and Sales Transactions. The data is identified by the ATTOM ID associated with the property.

Breaking Changes

  1. Any calls to Sales Trend and School endpoints must be upgraded to Property API v4
  2. Any calls to Property endpoints that make use of the geoids and/or provide geoids as part of the search parameters must be upgraded to Property API V4.
  3. If your use of the Property API does not include any of the above, then it is likely that no change is necessary at this time. We would however recommend upgrading to Property API V4 at your earliest convenience.
  4. All Property API endpoints have been rewritten. We encourage our customers to retest their own applications to ensure no regression errors have gone undetected.

For further information see Upgrading to Property API V4

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