ArcGIS provides easy access to your authoritative data for constituents, collaborators, and other organizations to use in their decision making. Sometimes source data are managed in external systems such as permitting, service requests, licensing, etc. In this session, we'll talk about the Koop.js open-source developer project where you can build custom adapters for third-party data sources to use directly in ArcGIS products and configurable apps. We'll also review how Koop.js can be used to integrate ArcGIS back into other platforms and API standards such as GeoRSS, ICS, DCAT, and more.