A system for intermediated communication between applications running on the same computer is presented. The system routes communication between a first application and a second application through a data broker on a remote server to avoid direct communication between the applications. The first application may be a desktop application, such as a word processing application, that has an add-in installed to facilitate communication through the data broker. The second application may be a web browser that includes a web client implemented using standard functionality of the web browser, without an application-specific plug-in. The data broker operates on a remote server to receive and direct communication between the applications. By eliminating direct communication between the applications, the data broker improves system security and reliability by utilizing communication protocols and capabilities already existing within the computer.