Nexus MLS Data Format

The Nexus MLS database currently adheres to version 2.0 of the RESO Data Dictionary, potentially with some custom fields included to account for locale-specific data or information not covered by the RESO standard. If you need assistance converting or mapping non-compliant data to the RESO Data Dictionary 2.0, please contact support@nexusmls.io. In addition, Nexus MLS follows the standard for RESO Web API implementation, which is based on OData Version 4.0.

Contained on the rest of this page are ways that developers may view and examine the Data Dictionary. As the Data Dictionary is updated and changed over time, support for future versions may be implemented.

RESO Data Dictionary

The official RESO Data Dictionary Spreadsheet for version 2.0 can be found here. This comprehensive spreadsheet allows you to explore various fields, their definitions, and corresponding data types across different resources. As newer versions receive support, additional links to their respective Data Dictionary spreadsheets will be provided here for your convenience.

For a more in-depth and structured exploration of the Data Dictionary, consider visiting the RESO Data Dictionary 2.0 Wiki. This wiki offers a detailed overview of the standard and its structure.

Data Dictionary Wiki Overview

The RESO Data Dictionary is comprised of the following overall elements:

  • Resources: The top level element that organizes major data categories such as Property, PropertyRoom, or Media.
  • Groups: Subcategories within each Resource that group together related fields
  • Fields: Specific pieces of data regarding a particular entity of a Resource
  • Lookups: Predefined values for certain fields that help to normalize data

Below are some examples of the various elements of the RESO Data Dictionary:

  • Resource Example: Property - Includes all the groups and fields needed to describe a particular property and/or listing
  • Group Example: Structural Group - Includes fields that describe the structure and makeup of a property (beds, baths, area, etc.)
  • Field Example: InteriorFeatures - Contains a list of features or description of the interior of a particular Property
  • Lookup Example: Chandelier - One of several possible Lookup values for the InteriorFeatures field, indicates that the Property has a chandelier

As the real estate industry evolves, so too will the standards. Nexus MLS plans to support future versions as they are released.

Nexus MLS RESO Web API Endpoints

Though Nexus MLS supports endpoints for all standard RESO resources, this documentation focuses only on the resources that are most commonly used. If you are working with any data or plan to use any endpoints from resources that are not included in the API reference section, please contact support@nexusmls.io so that we can provide assistance.

In addition to the informational resources discussed previously, the Nexus MLS RESO server offers an endpoint that returns metadata about the various resources and their schemas in either a JSON or XML format.

To request this metadata, use the following example, replacing 'YOUR_KEY_HERE' with your actual Nexus MLS API key:

const response = await axios.get(
  "https://api.nexusmls.io/$metadata?$format=application/json",
  {
    headers: {
      Authorization: "Bearer YOUR_KEY_HERE",
    },
  }
);