Source MLS  is a non-profit organization that allows MLSs to demonstrate the value of their data through a trademark badge that signals to data consumers that a listing comes directly from an MLS, and enables insight into where listings are displayed.

On April 15th, 2026, FBS will begin supporting Source MLS. At that time, for all participating MLSs, a SourceMLSURL field will appear with every listing record retrieved via the Spark API or RESO Web API. Developers must use this SourceMLSURL value, when present, to load & display a badge on their listing detail pages. Display requirements for the Source MLS badge can be found here, and details on how to load this badge are available here. We strongly recommend developers add conditional logic to automatically display the Source MLS badge if the SourceMLSURL field is present in the API listing payloads.

Our Developer Agreement and Spark API Terms of Use will also be updated on April 15th, 2026 with the following language:

  • 2.b.7 Source MLS Display and Tracking Compliance.
    Developer agrees that, where MLS Content includes any Source MLS, Inc. logo, URL, or tracking mechanism, Developer must (a) display the Source MLS logo as required by Source MLS, Inc.’s Display and Usage Requirements and (b) implement the Source MLS tracking mechanism for each listing detail page view. Failure to do so constitutes a material breach of this Agreement and Terms of Use.

 

Frequently Asked Questions

  • What do I need to do to prepare for FBS supporting Source MLS on April 15th, 2026?
    Before then, developers should be prepared to display the Source MLS badge on consumer-facing listing detail pages. The most scalable approach when working across multiple markets is conditional logic to automatically display the Source MLS badge any time the SourceMLSURL is present in the listing payload.
  • How can I tell whether a given MLS is participating in Source MLS?
    If an MLS is participating in Source MLS, a SourceMLSURL field will appear with every listing record. If there is no SourceMLSURL field with the listing record, the MLS is not actively participating in Source MLS.
  • Do I need to display the Source MLS badge in VOW or agent-only contexts?
    Consumer-related VOW displays, yes. Agent-only tools, no. The intent is to display for and track impressions for consumers.
  • Does FBS support Source MLS with RETS?
    No. FBS does not support Source MLS with RETS data feeds, as RETS is an old technology that will be discontinued before too much longer.