You've been able to do that for ages, a client automating Excel through COM and listening for events in Excel from script: https://news.ycombinator.com/item?id=

You've been able to do that for ages, a client automating Excel through COM and listening for events in Excel from script: https://news.ycombinator.com/item?id=37229850 https://news.ycombinator.com/item?id=37229850 Microsoft's advice page for wrapping Office in a web application fronted by ASP/ASP.Net: https://support.microsoft.com/en-us/topic/considerations-for-server-side-automation-of-office-48bcfe93-8a89-47f1-0bce-017433ad79e2 https://support.microsoft.com/en-us/topic/considerations-for... And that has links to documentation about Excel Web Services of old (on-premises SharePoint days, not sure if it translates to today's cloud), which is SOAP/HTTP: https://learn.microsoft.com/en-us/sharepoint/dev/general-development/walkthrough-developing-a-custom-application-using-excel-web-services?redirectedfrom=MSDN https://learn.microsoft.com/en-us/sharepoint/dev/general-dev...