There are APIs available on all major OSs that do this. Example: https://developer.apple.com/documentation/coreservices/1390584-uckeytranslate https://develope

There are APIs available on all major OSs that do this. Example: https://developer.apple.com/documentation/coreservices/1390584-uckeytranslate https://developer.apple.com/documentation/coreservices/13905... My memory is that if you press option E on a Mac, the translation function reports a non-zero state but no character output. You can detect this and call the translation function again with a space to get the diacritic by itself.