Spark RESO Web API
Spark's implementation of the RESO Web API, exposed as an OData service at the /Reso/OData endpoint and serving data shaped by the RESO Data Dictionary. Version 3 is the recommended service root; versions 2 endpoints remain documented. Resources are Property, Member, Office, Media, OpenHouse, Room, Unit, Green Verification, Power Production and Lookup. The OData $metadata document at https://replication.sparkapi.com/Version/3/Reso/OData/$metadata is the machine-readable contract, but it is not anonymously retrievable — it returned HTTP 401 on 2026-07-26. The same API keys used for the Spark API authorize this endpoint.