Nexus MLS Data Schema

The Nexus MLS database currently adheres to version 1.7 of the RESO Data Dictionary. As of right now, there are no plans to allow for custom and/or non-RESO fields in the database. If you need assistance converting or mapping non-compliant data to the RESO Data Dictionary 1.7, please contact [email protected].

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 1.7 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 1.7 Wiki. This wiki offers an extensive overview, organizing the Data Dictionary into a hierarchical tree structure that systematically categorizes resources and fields, making navigation and understanding more straightforward.

Wiki Tree Structure

The Data Dictionary is organized into a tree structure, providing an intuitive navigation scheme:

  • Resources: The top level, categorizing major real estate concepts such as Property, Member, Office, and Media.
  • Groups: Subcategories within Resources, refining the classification further.
  • Fields: Specific data points contained within Groups, detailing individual data elements.
  • Lookups: Also known as enumerations, providing predefined values for certain Fields to ensure data consistency.


  • Resource Example: Teams - Covers information about groups of members working together.
  • Group Example: Within the Teams resource, you might find groups like TeamAddress or TeamContactInfo, organizing related fields.
  • Field Example: BusinessName - Represents the name of a business entity.
  • Lookup Example: ContactStatus - Could have values like Active, Inactive, or On Vacation.

As the real estate industry evolves, so too will the standards. Nexus MLS is committed to supporting future versions of the RESO Data Dictionary as they are released, ensuring our platform remains at the forefront of data compliance and interoperability.

Nexus MLS Metadata Endpoint

The Nexus MLS RESO server offers an endpoint for metadata about resources and their schemas, available in JSON or XML formats.

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

const response = await axios.get(
    headers: {
      Authorization: "Bearer YOUR_KEY_HERE",