“The Visio team has steadily released more and more features to increase mobility across your organization. In November 2016, we brought Visio Online Public Preview for a group of Office 365 users—and their feedback was fantastic! Since then, we’ve enabled Visio Online for VSD file format and for users who are using email through Exchange Online, Outlook.com and Hotmail. In addition to online viewing, we’re excited to announce commenting for Visio Online, giving you and your team a place to review and discuss process flows, shape data and more without switching windows.”
The APIs enable programmatic access to the embedded Visio Online diagrams in a SharePoint Online page. As a mashup example, developers can create a custom overlay, such as a list of steps required to complete before moving forward in a process, that appears when users select or hover over a diagram shape.