Hello again. Thank you for your replies. Overrides the paste function of the operating system via keyboard shortcuts. Sorry for the misunderstanding, what I was saying by overriding is that it provides an alternative keyboard shortcut for pasting text, which is manipulated by the app in some way. Also, the app is QT-based since it is developed as a cross-platform app. One thing to note thought: Don’t try to use the Accessibility API for this. It’s not available in sandboxed apps. The functionality was implemented via the Accessibility API, but I'll try to find other solutions. If anyone has suggestions for other approaches, I'd be grateful to hear them. Thanks in advance!