Open Source in Finance Forum London 2025

There is a strong desire in the FDC3 community to support multiple app scopes within a parent app scope. FDC3's origins lie in desktop containers, and for web apps this meant hosting apps via urls in separate windows. This means micro-frontend containers in vanilla web browsers need to host apps in separate windows or iframes in order to use FDC3. This is appropriate when hosting apps from multiple vendors (e.g. for code isolation purposes) but is an undesirable restriction for apps from a single vendor. In particular, many organizations have existing platforms hosting separate web apps as modules within the same window (same DOM) by means of module federation or import maps. Retrofitting FDC3 support to such a platform is currently problematic. Beyond web apps, there are also similar challenges with composition in the case of native apps. The FDC3 Standard Working Group has been working on a solution, which involves the new concept of 'sub-agents'. This talk provides an overview of the motivation, the opportunity, the challenges, and the proposed changes to the FDC3 Standard to enable 'sub-agents' and multiple app scopes - for both browsers and other containers.