I would like to add a specific route to the ng serve command, because I need to deliver a json file from that endpoint. It contains runtime config for the angular app. In the prod env this is easily done by configuring the web server accordingly, however in dev environment I am struggling. Right now I solved it by simply starting up an nginx that does the job an letting ng serve know about it via proxy.conf.json. This works as expected but feels a bit cumbersome. I would like to get rid of the dev nginx. Any ideas?

when I try to ng xi18n –i18n-format=xlf
I get an error. When I run to app with ng serve there are no problem
It is an angular-cli 1.4.2

When I run for example a production build ng build --configuration production, then angular writes some information to the error log: